Unihedron Sky Quality Meter, Error Identification and Elimination

Background

This Unihedron Sky Quality Meter (Ser. No. 5739 / Mod. 2.17) has been used over a six-year period at various venues in South Africa. I noted that the first four to six readings in every series of measurements we took drifted lower before stabilizing. My revised operating procedure discards the first four reading in every series and this has virtually eliminated the initial drift of earlier measuring sessions. My results showed and still show inexplicable outliers which have a negative impact on the error profile of the results produced. By mounting the unit on a tripod and making sure it is level and exactly vertical instead of operating it while hand-held, I have reduced the number of outliers but not eliminated them.

  1. Experiment 1.

The results of the first experiment were obtained at Bergwater Lodge (-33°39’47.06″, 20°00’44.13″, 501m) near Montagu. The objective was to see if the readings taken with the Sky Quality Meter at the zenith (0°) and at 30° and 60° down from 0°, toward each cardinal direction varied and, if they varied, by how much. In experiment 1 the meter was hand-held.

  1. Results for Experiment 1.
The readings toward the east (E30°) and West (W30°) were consistently similar and both sets were slightly better (darker) than the zenith readings. The values toward the North (N30°) and south (S30°) were consistently less dark than the East & West readings with the N30° readings slightly better (darker) than the S30° ones. I have no explanation for the outlier in the S30°set.
The readings toward the east (E30°) and West (W30°) were consistently similar and both sets were slightly better (darker) than the zenith readings. The values toward the North (N30°) and south (S30°) were consistently less dark than the East & West readings with the N30° readings slightly better (darker) than the S30° ones. I have no explanation for the outlier in the S30°set.
The E30° readings were darker than either the 0° readings or the W30° ones. The W30° readings were marginally less dark than the 0° values. The values for N30° were quite close to the other values but not quite as dark and S30° was noticeably different and again the lowest (least dark) of the five sets.
The E30° readings were darker than either the 0° readings or the W30° ones. The W30° readings were marginally less dark than the 0° values. The values for N30° were quite close to the other values but not quite as dark and S30° was noticeably different and again the lowest (least dark) of the five sets.
The E60° readings were darker than either the 0° readings or the W60° ones and both sets were darker than the 0° values. The values for N60° and S60° were quite close to the other values but not quite as dark, however, all the different sets were much closer together than in Figures 1 and 2.
The E60° readings were darker than either the 0° readings or the W60° ones and both sets were darker than the 0° values. The values for N60° and S60° were quite close to the other values but not quite as dark, however, all the different sets were much closer together than in Figures 1 and 2.
The E30° readings were darker than either the 0° readings or the W30° ones. The W30° readings and the 0° values are very close to each other. The values for N30° and S30° were also quite close together but, in this case, the N30° values were marginally less dark than the S30° ones.
The E30° readings were darker than either the 0° readings or the W30° ones. The W30° readings and the 0° values are very close to each other. The values for N30° and S30° were also quite close together but, in this case, the N30° values were marginally less dark than the S30° ones.
The W60° readings were now the darkest ones followed by the E60° ones. The 0° readings and the S60° values are hardly distinguishable with the N60° values just slightly lighter.
The W60° readings were now the darkest ones followed by the E60° ones. The 0° readings and the S60° values are hardly distinguishable with the N60° values just slightly lighter.
Depiction of the % difference between zenith (0°) readings and other values.  Zenith values were taken as 100% so negative values indicate series of readings that were higher (darker) than zenith readings.
The depiction of the % difference between Zenith (0°) readings and other values. Zenith values were taken as 100% so negative values indicate series of readings that were higher (darker) than zenith readings.
  1. Discussion of Experiment 1.

The results in Figures 1 to 6 show that the values given by the Sky Quality Meter do differ at the different cardinal points and also at 30° and 60 ° down from the zenith (0°). At both 30° and 60°, the readings were darker toward the west and east than at 0° and less dark toward the north and south.

In order to illustrate the differences more clearly, the Sky Quality Readings were calculated as a percentage of the value obtained for the zenith (0°) and these results are depicted in Figure 7 (above). Here it is clear that W30°, E30°, W60° & N60° readings were consistently darker than the readings at 0° (average -0.4222) while those for N30°, S30°, N60° & S60° were lighter by a larger margin (average 0.8175).

  1. Future Planning.

One set of results is not enough to draw any general conclusions from and I suspect the results will vary from site to site. In all probability, they will also vary from season to season for the same site as the position of objects in the sky changes seasonally. I will select a suitable site and repeat the test at three monthly intervals over the course of one year.

  1. Experiment 2.

The values in the second experiment were obtained at the SAAO Hostel near Sutherland (-32°22’35.29″, 20°48’18.56″, 1703m). I wanted to verify that my Unihedron Sky Quality Meter’s readings were consistent at 0° when the instrument was rotated 90° between consecutive readings around the vertical axis. In experiment 2 the meter was tripod-mounted and the tripod was set to level and vertical using a spirit level.

  1. Results for Experiment 2.
The two sets of south/north (S/N) -readings are consistently darker than the west/east (W/E) -readings. Despite the three outliers, the two sets of S/N-readings lie quite close together as do the two sets of W/E readings.
The two sets of south/north (S/N) -readings are consistently darker than the west/east (W/E) -readings. Despite the three outliers, the two sets of S/N-readings lie quite close together as do the two sets of W/E readings.
  1. Discussion of Experiment 2.

From these results, it appears that the Unihedron Sky Quality Meter I use does, in fact, give different readings in the two 90° orientations around the vertical axis that were tested. Even if one takes into consideration the three outlier values the S/N values are consistently darker than the W/E values. It seems possible to produce quite different sets of values, and therefore draw different conclusions depending on how the instrument is orientated around the vertical axis.

  1. Future Planning.

I will repeat the test using all four possible 90° orientations around the vertical axis. On that occasion, it will hopefully have the time to take two or three sets of readings on the same evening and also to repeat all of them on two or more consecutive evenings.

Stargazing visit to Leeuwenboschfontein: Monday 26th of December 2016 to Sunday 01st January 2017.

The day after Christmas we (Lynnette, Snorre and I) arrived at Leeuwenboschfontein just before lunch. We were followed later in the week by Iain Finlay – Willem stayed at home keeping their cats, Tiger and Aimé, company. Rob Bark with his wife Michelle and daughter Victoria were next in, followed, eventually, by Paul Kruger, with his famous breakfast. Dave, Spiro and Sharon were due to fly in from up north but eventually drove down due to thundery weather over the central parts of the country.  Martin Lyons had plans to fly in as well but gave up on that idea as the altitude, heat and short runway made it unsafe for the plane he was going to use. Auke could not make it either because of last minute complications.

I have to sit here all morning and wait for them to finish so that we can get going and go to Leeuwenboschfontein.
I have to sit here all morning and wait for them to finish so that we can get going and go to Leeuwenboschfontein.
TOP LEFT: Earth shadow and Venus’s girdle with one of the nice new bungalows at Leeuwenboschfontein in the foreground. BOTTOM LEFT: Iain Finlay, Rob Bark and I on the stoep of bungalow no. 5; one of the spanking new bungalows at Leeuwenboschfontein. TOP RIGHT: Two single beds pushed together to make a double bed in our bungalow. MIDDLE RIGHT: The bunk-bed and washbasin in our bungalow. BOTTOM RIGHT: Two burner gas stove, fridge and table with two benches in our bungalow.
TOP LEFT: Earth shadow and Venus’s girdle with one of the nice new bungalows at Leeuwenboschfontein in the foreground. BOTTOM LEFT: Iain Finlay, Rob Bark and I on the stoep of bungalow no. 5; one of the spanking new bungalows at Leeuwenboschfontein. TOP RIGHT: Two single beds pushed together to make a double bed in our bungalow. MIDDLE RIGHT: The bunk-bed and washbasin in our bungalow. BOTTOM RIGHT: Two burner gas stove, fridge and table with two benches in our bungalow.
Dalzicht on the left, with bungalows one and two hidden behind the island in the road. They are both equipped with their own bathrooms. Bungalows four to six on the right use the ablution block hidden in the background behind unit three.
Dalzicht on the left, with bungalows one and two hidden behind the island in the road. They are both equipped with their own bathrooms. Bungalows three to six, on the right, use the ablution block hidden in the background behind unit three.

Monday evening was fine, Tuesday evening was completely clouded over and Wednesday evening was very windy in the early evening with a fair amount of cloud that cleared after midnight. Thursday night was a repeat of Wednesday and Friday was more of the same. Saturday was a near-perfect night to round off the weekend.

TOP: Sunset on the 30th of December. SECOND FROM THE TOP: Sunset about 20 minutes later. BOTTOM: The Moon going down for the last time in 2016 over Leeuwenboschfontein.
TOP: Sunset on the 30th of December. SECOND FROM THE TOP: Sunset about 20 minutes later. BOTTOM: The Moon going down for the last time in 2016 over Leeuwenboschfontein.

One thing that is a problem at Leeuwenbosch is the lighting along the entrance road and in the garden between the guest houses.  They are all these horrible round white things that distribute light in all directions. Some sort of a cover that prevents light from escaping upward and horizontally, would solve the problem and the use of cooler bulbs would also help. I temporarily solved the problem by taking the bulbs out as soon as it looked as if all the folks in the houses had gone to bed and then replaced them when I was done observing. Johan Roux, however, has shown me where the light switches for these lights are and it is now a case of flicking two switches and seeing conditions around the guest houses and new chalets will improve by at least 200%.

TOP LEFT: Paul taking a break on the way to Leeuwenboschfontein. TOP RIGHT: Paul is a firm believer in a hearty breakfast to start his day. BOTTOM LEFT: Paul’s braai and bottle of wine in preparation for the night’s photography. BOTTOM RIGHT: Paul’s very nice set of star trails taken from Leeuwenboschfontein.
TOP LEFT: Paul taking a break on the way to Leeuwenboschfontein. TOP RIGHT: Paul is a firm believer in a hearty breakfast to start his day. BOTTOM LEFT: Paul’s braai and a bottle of wine in preparation for the night’s photography. BOTTOM RIGHT: Paul’s very nice set of star trails taken from Leeuwenboschfontein.

The camp, however, was a bigger problem this time around. Because it was the holiday season and specifically the New Year’s weekend, the camp was full of revellers who switched on all possible lights including that infernal spotlight on the mast in the middle of the camp. Why get tipsy in the dark, after all? The light spill from this lot even affected the seeing down in the telescope area next to the runway, almost a kilometre away.

At least these light pollution problems will not be a problem during the SSP because we have Johan’s permission to switch everything off for that weekend.

On the subject of light pollution, I recorded a set of dark sky readings for those of the readers who might be interested.

MSAS = Magnitudes per Square Arc Second NELM = Naked Eye Limiting Magnitude
MSAS = Magnitudes per Square Arc Second
NELM = Naked Eye Limiting Magnitude

I also recorded some weather data, using Hans van der Merwe’s clever data logger. Here are some results that might interest amateur astronomers.

Graphic representation of some of the weather data from Hans van der Merwe's data logger.
Graphic representation of some of the weather data from Hans van der Merwe’s data logger.

Leeuwenboschfontein Astronomy Weekend: 11 December 2015.

On Wednesday the 09th we set off for Leeuwenboschfontein (visit their website to by clicking here) within minutes of our scheduled departure time. We were quite chuffed, online as we do not often manage to meet our departure deadlines for trips like this. We stopped off at Die Veldskoen Padstal (visit their Facebook page by clicking here) about 4 km north of De Doorns for a light lunch, prescription buying a few bottles of wine and a bag of fresh cherries. For good, friendly service and quality food I can really recommend this place.  We have been stopping off there since 2008 and not been disappointed once. At Leeuwenboschfontein we found that the permanent caravans had been nicely enclosed to afford privacy and protection against the wind which often becomes quite chilly in the evenings.

Willem and Iain were already camped on site, Alan and Rose arrived on Thursday and moved into the second permanent caravan, followed by Barry and Miemie who occupied Dalzicht guest house. Johan, Nellie and Dominique moved into the third caravan on Friday and Auke, Chris, Lenelle and Susan, all camping, also arrived during the course of Friday. Joan, who runs the reception at Leeuwenboschfontein, was kind enough to lend us a deepfreeze for the campers to use over the weekend, which was very useful.

TOP LEFT: Sunrise at Leeuwenboschfontein looking down the Nougaskloof roughly in the direction of the Anysberg which lies to the right but out of the picture. TOP RIGHT: Sunset, but looking east from Leeuwenboschfontein. BOTTOM LEFT: The same sunset as in the previous photograph but looking west from the camping area. BOTTOM RIGHT: The same sunset reflected in the dam in the campsite at Leeuwenboschfontein.
TOP LEFT: Sunrise at Leeuwenboschfontein looking down the Nougaskloof roughly in the direction of the Anysberg which lies to the right but out of the picture. TOP RIGHT: Sunset, but looking east from Leeuwenboschfontein. BOTTOM LEFT: The same sunset as in the previous photograph but looking west from the camping area. BOTTOM RIGHT: The same sunset reflected in the dam in the campsite at Leeuwenboschfontein.
TOP LEFT: The very neatly and sensibly enclosed permanent caravan sites at Leeuwenboschfontein with the two telescopes under their shiny protective wraps. TOP RIGHT: The handy table with power outlet and light behind the shade cloth screen very nicely extend ones living space from inside the caravan to the space in front and the shade cloth affords on a great deal privacy as well as protection from the prevailing wind. BOTTOM LEFT: The tranquil sunset view across the dam from our caravan. BOTTOM RIGHT: The 12” being prepared for the night’s working session.
TOP LEFT: The very neatly and sensibly enclosed permanent caravan sites at Leeuwenboschfontein with the two telescopes under their shiny protective wraps. TOP RIGHT: The handy table with power outlet and light behind the shade cloth screen very nicely extend ones living space from inside the caravan to the space in front and the shade cloth affords one a great deal privacy as well as protection from the prevailing wind. BOTTOM LEFT: The tranquil sunset view across the dam from our caravan. BOTTOM RIGHT: The 12” being prepared for the night’s working session.

Thursday evening everyone socialized at our caravan but the evening was also very good from an astronomy point of view with excellent seeing conditions. Rose and Lynnette went to bed shortly after midnight but Alan persevered until around 02:00. Barry also put in some time with the telescope and camera and, amongst other things produced a beautiful shot of the Tarantula Nebula (NGC 2070 or 30 Doradus). I was up until just before 06:00.

Friday evening saw more socializing in the late afternoon and early evening with the telescope work taking place later on and after midnight. The seeing was very good. Early on Auke and Barry remarked that one could walk away from the group around the fires and, without too much effort and hardly any dark adaptation, see 47 Tucanae (NGC 104), Omega Centauri (NGC 5139), the Jewel Box (NGC 4755), Eta Carinae, the Southern Pleiades (IC 2602) and the Andromeda Galaxy (M31/NGC 224).

Readings were taken with the Unihedron Sky Quality Meter (visit their website by clicking here to find out more) on the 09th, 10th & 11th and the average of 20 readings on each night was 21.70, 21.69 & 21.58 (Magnitudes per Square Arc-Second or MSAS) respectively. This converts NELM (Naked Eye Limiting Magnitude) values of 6.4816, 6.4772 & 6.4168. Using the Loss of the Night application and viewing 30 stars, at the same time as taking the Sky Quality readings, gave a limiting magnitude of >5 ± 0.1 on all three occasions.

Snorre, with his flashing red light. He seems exceptionally at home in the rocky and bushy terrain at Leeuwenboschfontein and tends to disappear at night. With the light we can find him more easily and we think that it not only affords him some protection against predators, but also warns his potential prey of his approach, much to his disgust.
Snorre, with his flashing red light. He seems exceptionally at home in the rocky and bushy terrain at Leeuwenboschfontein and tends to disappear at night. With the light we can find him more easily and we think that it not only affords him some protection against predators, but also warns his potential prey of his approach, much to his disgust.
TOP LEFT: Auke and Chris in a pensive mood. TOP RIGHT: Lynnette, Rose and Alan. BOTTOM LEFT: Lenelle with her back to the camera, Nellie, Auke, Chris and Miemie. BOTTOM RIGHT: Chris, Lenelle, Miemie just visible, Johan with his back to the camera, Barry, Lynnette, Alan sitting on his haunches with his back to the camera and Rose. On the table is the bottle of sparkling wine to celebrate Alan and Rose’s anniversary.
TOP LEFT: Auke and Chris in a pensive mood. TOP RIGHT: Lynnette, Rose and Alan. BOTTOM LEFT: Lenelle with her back to the camera, Nellie, Auke, Chris and Miemie. BOTTOM RIGHT: Chris, Lenelle, Miemie just visible, Johan with his back to the camera, Barry, Lynnette, Alan sitting on his haunches with his back to the camera and Rose. On the table is the bottle of sparkling wine to celebrate Alan and Rose’s anniversary.
TOP: Nellie, Johan again with his back to the camera, Lenell, Chris, Mienie, Barry, Lynnette, Alan and Rose. BOTTOM: Auke, Nellie with her back to the camera, Chris, Miemie, Barry, Lenelle Susan with her posterior to the camera and Lynnette.
TOP: Nellie, Johan again with his back to the camera, Lenelle, Chris, Miemie, Barry, Lynnette, Alan and Rose. BOTTOM: Auke, Nellie with her back to the camera, Chris, Miemie, Barry, Lenelle Susan with her posterior to the camera and Lynnette.

On Saturday the weather closed in and light rain fell so observing was out as was the customary braai under the stars. Fortunately Leeuwenboschfontein has a very nice enclosed central lapa for just such occasions. We spent a pleasant evening there, out of the wind and rain and warmed by the braai-fires. Alan opened a bottle of sparkling wine to celebrate he and Rose’s wedding anniversary, which was the following day, so it really was a festive occasion. Later in the evening Snorre managed to attract a lot of attention by climbing a tree that proved difficult to get out of but, once everybody had stopped making a fuss, he did what cats normally do; climbed down on his own.

Supper on the grill on Saturday evening in the boma.
Supper on the grill on Saturday evening in the boma.
LEFT: Auke checking out the weather and contemplating the pile of calendars waiting for him at home. RIGHT: Miemie and Barry.
LEFT: Auke checking out the weather and contemplating the pile of calendars waiting for him at home. RIGHT: Miemie and Barry.

Sunday was overcast too, but most people had planned to leave on Sunday in any case. Chris left early, followed by Johan, Nellie and Dominique and then Lenelle and Susan.  Alan and Rosemary left just after lunch and Auke, who had intended staying until Tuesday, also decided to leave because the weather forecast did not look promising, from an astronomical point of view, for the next two evenings. In any case he had a pile of calendars to pack. Before Auke left we looked over the facilities being prepared in the large shed adjacent to De Oude Opstal guest house and they look very promising indeed. With only Willem, Iain, Lynnette, Snorre and I in the camp and Barry and Miemie in Dalzicht Leeuwenbosch was suddenly very quiet. On Monday Barry, Miemie and the Fosters packed up, said goodbye to Joan and to Leeuwenboschfontein and left the camp to Iain and Willem.

TOP: Crux or the Southern Cross is the smallest of the 88 constellations but other than Orion and Scorpius it is probably one of the most distinctive. Two of the stars in Crux appear to have planets and it also contains the distinctive open cluster known as the Jewel Box (NGC 4755) as well as the extensive dark nebulae known as the Coal Sack. Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 5s – f/1.8, 30 photographs stacked and processed with PhotoScape ® BOTTOM: Star trails in the vicinity of Orion. Legend: M1 to M4 are meteor trails and A is the tremor caused by our illustrious President playing ping-pong with his Finance Ministers. Actually, this is the result of Snorre stretching up against the tripod to play with the flashing green light on the camera. B is the trace of the Orion Nebula (M42/NGC 1976) and C indicates the traces of Orion’s three belt stars (Alnitak, Alnilam & Mintaka) also known as the Three Kings or the Three Sisters. Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 4s – f/1.8, The image was generated from 93 photographs taken at 38 second intervals.& processed with StarStax ®
TOP: Crux or the Southern Cross is the smallest of the 88 constellations but other than Orion and Scorpius it is probably one of the most distinctive. Two of the stars in Crux appear to have planets and it also contains the distinctive open cluster known as the Jewel Box (NGC 4755) as well as the extensive dark nebulae known as the Coal Sack.
Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 5s – f/1.8, 30 photographs stacked and processed with PhotoScape ®
BOTTOM: Star trails in the vicinity of Orion.
Legend: M1 to M4 are meteor trails and A is the tremor caused by our illustrious President playing ping-pong with his Finance Ministers. Actually, this is the result of Snorre stretching up against the tripod to play with the flashing green light on the camera. B is the trace of the Orion Nebula (M42/NGC 1976) and C indicates the traces of Orion’s three belt stars (Alnitak, Alnilam & Mintaka) also known as the Three Kings or the Three Sisters.
Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 4s – f/1.8, The image was generated from 93 photographs taken at 38 second intervals.& processed with StarStax ®
TOP: Orion Nebula (M42/NGC 1976) It is a diffuse nebula situated in Orion’s sword at a distance of about 1340 light years. It is the closest area to the Earth in which there is a large amount of star formation in progress. M42 is about 24 light years wide. BOTTOM: Omega Centauri (? Cen/NGC 5139) The largest globular cluster in the Milky Way. Situated at 15 800 light years from the Earth it has a diameter of about 150 light years it contains an estimated 10 million stars. Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 4s – f/1.8, 20 photographs stacked and processed with PhotoScape ®
TOP: Orion Nebula (M42/NGC 1976) It is a diffuse nebula situated in Orion’s sword at a distance of about 1340 light years. It is the closest area to the Earth in which there is a large amount of star formation in progress. M42 is about 24 light years wide. BOTTOM: Omega Centauri (? Cen/NGC 5139) The largest globular cluster in the Milky Way. Situated at 15 800 light years from the Earth it has a diameter of about 150 light years it contains an estimated 10 million stars.
Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 4s – f/1.8, 20 photographs stacked and processed with PhotoScape ®
Eta Carinae at bottom left is a star grouping that contains two stars with a combined brightness that is several million times that of our Sun, It is situated at about 7 500 light years from the Earth in the constellation Carina. The primary star is expected to explode as a supernova in the not too far distant astronomical future. The Southern Pleiades (IC 2602) is an open cluster in the constellation Carina and contains about 60 stars. This cluster is between 35 and 45 million years old and lies approximately 500 light years away with a diameter of about 15 light years. Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 5s – f/1.8, 15 photographs stacked and processed with PhotoScape ®
Eta Carinae at bottom left is a star grouping that contains two stars with a combined brightness that is several million times that of our Sun, It is situated at about 7 500 light years from the Earth in the constellation Carina. The primary star is expected to explode as a supernova in the not too far distant astronomical future. The Southern Pleiades (IC 2602) is an open cluster in the constellation Carina and contains about 60 stars. This cluster is between 35 and 45 million years old and lies approximately 500 light years away with a diameter of about 15 light years.
Camera: Nikon D5100, Lens: AF-S NIKKOR 50mm f/1,8G, ISO: 1000, Shutter: 5s – f/1.8, 15 photographs stacked and processed with PhotoScape ®

We arrived home safely and started the dreaded unpacking and packing away to wrap up our final visit to Leeuwenboschfontein for 2015, but we will be back in 2016. We did not make use of the stargazing enclosure next to the runway this time because there were very few other people in the camp so we could control the lights. A problem with the water supply has also resulted in the grass dying inside the enclosure so it would have been very sandy and dusty in there. Johan snr has promised the grass will be back in 2016 and so will we, hopefully on a regular basis.

Evaluation of a potential stargazing site near Montagu: December 2014

Bon Solitaire, a potential stargazing site near Montagu (33° 49’ 04”S 20° 12’ 44”E & 276 m)

How to get there is important so let’s start with the instructions. Once in Montagu one leaves the town on the road to Barrydale. At 0,4 km outside Montagu one crosses a bridge and 0,67 km after the bridge there is a turnoff to the left. One of the names on the various signposts at the turnoff is for Talana. Turn left here and follow the road. Stay on the tar and do not turn off. About 5 km after the turnoff it becomes a gravel road and 2 km after that there is a very short tarred section and the guest house is on your left. From Brackenfell to there is about 170 km.

The place is run by Christine’s daughter Ruzanne and her husband Raoul, but Christine does most of the day to day management. The accommodation is good and could at a push sleep six if there were children in the group but four adults would be comfortable in the two double beds. The bathroom is small but modern. There is a wide wooden deck, of which one half is roofed, and it has a convenient braai. There is also an inside braai for those chilly days and the less hardy souls. Braai wood can be purchased from the adjacent farm. The cottage has a fridge/freezer, a microwave, a two plate cooker/oven-combination and all crockery and cutlery. Bedding is supplied but no towels. The mobile reception is very unreliable. During the fruit season one can buy fruit from the surrounding farms.  Lynnette and I bought 10 kg of apricots from Flip and Christine Haasbroek of Lank-Gewag Boerdery just across the road from the cottage. Price for the cottage is available on request from Ruzanne. I almost forgot to say there is a television as well.

Vie from the deck in front of the cottage to the East
Looking east from the deck in front of the cottage.  There is a drop of about one metre to get to the ground and the Beefwood trees on the right also limit viewing from here. To get a telescope out into the open area will be quite an exercise
Looking south-southeast from the deck. The Beefwoods on the left are again a problem for viewing in that direction
Looking south-southeast from the deck. The Beefwoods on the left are again a problem for viewing in that direction
Looking almost directly west from the deck.  The open area is a good viewing area although the cottage blocks ones view to the north
Looking almost directly west from the deck. The open area is a good viewing area although the cottage blocks ones view to the north
A panoramic view from the garden to the west of the cottage.
A panoramic view from the garden to the west of the cottage.
Up the steps to the cottage. the incline is fairly steep.
Up the steps to the cottage. The incline is fairly steep. As mentioned one half of the deck is roofed and the other not. The outside braai is visible to the left of the steps.  In this view one is looking north
We bought apricots from this friendly couple just across the road from the cottage
We bought apricots from this friendly couple just across the road from the cottage
The Mountains to the east bordering the northern side of the road which leads to the Poortjieskloof Dam are quite spectacular when seen close up
The Mountains to the east bordering the northern side of the road which leads to the Poortjieskloof Dam are quite spectacular when seen close up. Can you see the mountain retreat somebody has built up there?
This is my idea of a mountain retreat.
This is my idea of a mountain retreat.
The outside braai and the coals are just right
The outside braai and the coals are just right
Braai is going and supper is almost ready!
Braai is going and supper is almost ready!

Covered parking for two vehicles is available just inside the main entrance, adjacent to the main dwelling. From there access to the cottage is via a well-kept, enclosed lawn and garden, with a salt water swimming pool. The garden and pool are for the use of the cottage occupants. Be forewarned that you have to carry everything from the car to the cottage through the garden and back again so a small trolley will be a great help.

A composite of the inside of the cottage
A composite of the inside of the cottage.  Inside bedroom double bed, Inside bedroom sleeper couch, Outside bedroom beds, Inside braai, microwave & hotplate/oven, Kitchen, Bathroom, Entrance off deck, Roofed area of the deck, Outside braai & open area of the deck

As far as astronomy is concerned Raoul, Ruzanne and Christine are very accommodating and switch off all outside lights as well as all inside lights facing the cottage. The garden between the house and the cottage is a safe area but the horizons are quite high from there. One could also put a telescope on the uncovered section of the deck which improves the south eastern to south-western horizons. One could also put a telescope in the open area on the eastern side of the house but, given the logistics of carrying the equipment there I would use the lawn. On our visit the clouds moved in after sunset and it was eventually completely overcast on Sunday evening in a repeat of the conditions at Kopbeenskloof. Monday evening was better and we set up the telescope in the driveway next to the main house and the cars. The area is not level but certainly workable as one has a paved surface underfoot. Seeing was reasonable given the presence of high level clouds that eventually took over after 23:00. The area is definitely dark except for two security lights in adjacent farms but it is possible to position the telescopes so that these are not in one’s direct line of sight. The dark sky readings 21,06 MSAS (average of ten readings, std. dev. of 0,030984) and 21,03 MSAS (average of ten readings, std. dev. of 0,026854) (MSAS = Magnitudes per Square Arcsecond). and all clouds had reassuring black undersides.

On a completely different note I noted that there is the start of a cactus infestation and this is something which is quite widespread throughout the Karoo areas of South Africa. These plants were imported and used as garden and ornamental plants but once they escape into the veld they become a problem and there is unfortunately the start of such an infestation in the kloof adjacent to the cottage. Go here to read more about cactus infestation by this specific plant.

A cactus plant in the garden and I think this is Cereus jamacaru
A cactus plant in the garden and I think this is Cereus jamacaru
Here plants in the veld in a kloof adjacent to the cottage can be seen
Here plants in the veld in a kloof adjacent to the cottage can be seen

I think the cottage is quite suitable for astronomy provided one does not want to work too close to the horizons, especially to the north and east. Astrophotographers wanting to cover selected objects in the open areas should be quite happy here. I think the cottage has a lot of potential for astronomers who want to take their partners or families along. As a general breakaway for a small group or for a family I think it is an excellent base given the close proximity of Montagu and Barrydale. Ruzanne’s telephone number is 072 177 3013 and is best used during office hours, given the unreliable nature of the mobile service in the area. Her e-mail address is ruzannebeetge@gmail.com.

Sunset over the Langeberg Mountains to the west
Sunset over the Langeberg Mountains to the west. The pool, covered parking and main house are clearly visible at the end of the garden

Dark Sky outing to Kopbeenskloof during December 2014

Dark Sky at Kopbeenskloof (33° 35’ 52”S, 19° 57’ 26”E & 1248 m) in December 2014

I previously reported on the venue so please go here for those details. On this occasion we left later than planned on Thursday morning because of complications caused by having the Blaauwklippen event back to back with the deep sky outing. Iain Finlay was on the road at more or less the same time and he waited for us at the Shell service station in Worcester so we could travel together for the last part of the journey. We stopped off at the Veldskoen Padstal just past De Doorns for coffee and something to eat. The Veldskoen does a very good toasted cheese sandwich and a superb cheese cake. The other items on their menu are also excellent so next time you pass there pop in and treat yourself.

The Veldskoen Padstal is a very nice stop before the long haul north if one is headed for Sutherland, for instance. We were not going that far but stopped of in any case.
The Veldskoen Padstal is a very nice stop before the long haul north if one is headed for Sutherland, for instance. We were not going that far but stopped of in any case.

Next stop was Kopbeenskloof where we were welcomed by the owner, Wouter Stemmet. If you want to know more about what Wouter and Elsabé do at Kopbeenskloof please visit their website here. There were all sorts of communication problems in the week leading up to this visit. As a result Wouter was not quite prepared for us but he quickly rectified that and we could start unloading and settle in. Despite beautiful clear skies during the day the evening turned cloudy and then went completely overcast with clouds coming in from the south east driven by a very chilly wind. Lynnette and I were short on sleep after our Blaauwklippen escapades of the previous night so we did not really complain about getting to bed early. I got up somewhere around 03:00 to check the weather but we still had clouds from horizon to horizon.

Lynnette and Iain chat on the stoep of the guest house while Snorre and I go for a walk. Note the colour of the sky
Lynnette and Iain chat on the stoep of the guest house while Snorre and I go for a walk. Note the colour of the sky
The guest house from a distance and the sky is clearly not going to allow us to do astronomy
The guest house from a distance and the sky is clearly not going to allow us to do astronomy
Nice sunset and this is also the area where the sky glow from Worcester and De Doorns is most prominent
Nice sunset and this is also the area where the sky glow from Worcester and De Doorns is most prominent

Friday morning was still cloudy but by mid-morning we had bright blue skies all around. Eddy and Jannie Nijeboer arrived later that afternoon after having struggled with the last section of our route instructions. These will be updated and made more user-friendly. By late afternoon Thursday’s weather pattern repeated itself and by 19:30 it was almost completely overcast and quite chilly. We were also concerned about Auke as we could not contact him and neither could he reach us. If Eddy and Jannie had struggled with the directions Auke could be well on his way to the Anysberg by now. It later materialized that domestic problems had prevented him from attending. So we again opted for a relatively early night. The 03:00 inspection was negative again but we got up at 06:00 and went for a walk with Snorre.

The Earth's shadow making a distinctive blue band in the west as sunrise approached
The Earth’s shadow making a distinctive blue band in the west as sunrise approached
Matroosberg at sunrise as not many have been privileged to see it
Matroosberg at sunrise as not many have been privileged to see it
Lynnette's mid-morning siesta.  Note the jacket and cap - it was not warm.
Lynnette’s mid-morning siesta. Note the jacket and cap – it was not warm.
Snorre and I on a section of his walk
Snorre and I on a section of his walk

Saturday was a beautiful, cloudless day and we went down to the farm where Wouter showed us around the other amenities he and Elsabé had to offer. The five of us spent some time looking around. The guest house, situated about a kilometre away from the farmhouse, which will sleep 10 at a push but eight is a more realistic number and six, as far as I am concerned, is just right. At the main house there are chalets and other facilities to cater for large groups and functions. The enclosed entertainment area, inside braai and large kitchen and the chalets definitely have possibilities. However, sleeping 12 people per chalet will not work for astronomers and Wouter says he would be quite happy to put up two people per chalet, which would mean lots of storage space on the empty beds.  The ablution facilities are quite adequate for the number of chalets. There is a large grassed area, which Wouter intends expanding, which would work well for a telescope area but has also been used in the past for camping and caravans. Power can be laid on by long leads from the kitchen area for the astrophotographers and they can actually be grouped separately from the telescopes which addresses the light pollution problem too. There is a very rustic cottage, the K’roo Huise situated some way away from the main house for those who would really like to rough it as it has no electricity and water is heated for showers by means of an old fashioned “donkey”.

From left to right, Jannie, Wouter, Eddy and Iain in the enclosed entertainment area.  This would also make a nice sheltered viewing area for the astrophotographers
From left to right, Jannie, Wouter, Eddy and Iain in the enclosed entertainment area. This would also make a nice sheltered viewing area for the astrophotographers
In the spacious inside braai area adjacent to the large kitchen
In the spacious inside braai area adjacent to the large kitchen
The chalets from the outside
The chalets from the outside
Inside a chalet
Inside a chalet
A view of the second group of chalets
A view of the second group of chalets
This grassy area next to the one group of chalets can be used for a telescope area but has also served as a camping area
This grassy area next to the one group of chalets can be used for a telescope area but has also served as a camping area
View from the parking area of the K'roo Huisie
View from the parking area of the K’roo Huise.  The one on the right.
Eddy on the stoep of the K'roo Huisie
Eddy on the stoep of the K’roo Huise
Panoramic view from in front of the K'roo Huis
Panoramic view from in front of the K’roo Huis
There is a large parking area but it is dusty which means that after rain it will be muddy and there is no shade for the vehicles. The large building in the background is the ablution block
There is a large parking area but it is dusty which means that after rain it will be muddy and there is no shade for the vehicles. The large building in the background is the ablution block

After the inspection we went back to the guest house and prepared for an evening’s star gazing. There were one or two small clouds lurking around but in general the evening was quite productive for stargazing with Kitchi Koo and the 12” Dobby. It was as definitely dark with dark sky readings of, 21,50 MSAS (average of ten readings, std. dev. of 0,024518) and 21,52 MSAS (average of ten readings, std. dev. of 0,024518) (MSAS = Magnitudes per Square Arcsecond). All clouds were definitely black, and the only light pollution is to the south west where Worcester and De Doorns throw up a considerable sky glow, especially if there is low cloud in that area. The seeing was not all that good because of the instability in the upper atmosphere but on an absolutely clear night the seeing should be excellent considering that the altitude there is only about 200m lower than Sutherland. By around 02:00 the dew made it impossible to continue without heaters on our telescopes. In any case the temperature had dropped to an unexpectedly low 09°C by then, so bed was a very attractive proposition.

Sunsets tend to be quite spectacular from the guest house
Sunsets tend to be quite spectacular from the guest house
Sunset through the trees on the western side of the guest house
Sunset through the trees on the western side of the guest house
Sunset framed by the ruins of an old barn
Sunset framed by the ruins of an old barn

The next morning we had a leisurely breakfast and proceeded to pack up. By about 12:00 we said our goodbyes and left, followed closely by Iain.  Jannie and Eddy were a bit slower off the mark, but probably left shortly after us. We did not go straight home but headed for Montagu where we wanted to take a look at a potential venue recommended by Christine.

The all important notice board we left out of the instructions on how to get to Kopbeenskloof.  This is the turnoff from the R318 and makes no mention of Kopbeenskloof but one has to turn left her. Kopbeenskloof is signposted 6 km further down the road after you turn left here
The all important notice board we left out of the instructions on how to get to Kopbeenskloof. This is the turnoff from the R318 and makes no mention of Kopbeenskloof but one has to turn left here. Kopbeenskloof is signposted 6 km further down the road after you turn left here

Kopbeenskloof – May 2014

Exploring the Astronomy Potential at Kopbeenskloof

This report is a bit late.  I thought I had written it and obviously I hadn’t so now I have to write it and look as sheepish as possible about the fact that it’s so late.

In May Lynnette and I went of to investigate a place we’d had our eye ever since we’d visited Leeuwenboschfontein a few kilometres further down the road in 2012. Other than the ominous sounding name it has the added attraction of being situated at over 1200 m above sea level and that, makes it one of the highest farms in the Western Cape Province.  For the astronomers who also hike or walk during daytime, there are lots of trails and hikes and the farm is also ecologically interesting as it straddles the transition from typical Renosterveld to the Cape Mountain Fynbos.

The farm is run by Wouter and Elsabé Stemmet and regularly hosts groups of up to 200 from various youth organizations such as the Voortrekkers and Land Care & Land Services. These groups make use of a number of very basic wooden chalets containing only bunk beds. For the chalets there are adequate ablution facilities and a large, well equipped kitchen as well as an outside braai area. Wouter and Elsabé also cater for large functions and large groups, if asked to do so.

View of the one group of chalets
View of the one group of chalets
View of one of the second group of chalets
View of one of the second group of chalets
The very nice outside braai area for the chalets
The very nice outside braai area for the chalets
Part of the interesting inside braai area
Part of the interesting inside braai area

A separate camping area for tents and caravans that has its own ablution facilities is also available.

There is a rustic cottage for four that has no electricity and one heats the shower water by making a fire, situated about 200 m from the main house and the chalets.

The guest house, that could sleep nine in three en-suite bedrooms with double beds and three single beds in open areas, is situated about two km away from the main house and the chalets. The house has a kitchen with a stove, microwave and fridge and also has a large inside fireplace suitable for having a braai, should the weather turn nasty. All bedding and towels are supplied and further details can be found on their website if you go here.  One last thing is that mobile phone reception is limited to one spot in the garden of the main house and I do not know if one can get a signal for all three service providers there.

To get there one takes the R318 from the N1 and, after 26 km you turn left onto the Nougaspoort gravel road. After six km the turnoff to Kopbeenskloof is on your right and then you just follow the road to the main farm house, the chalets and the rustic cottage, or go past the house, keeping to the left and after two gates, you will be at the guest house.

The reason we went there was to try and evaluate Kopbeenskloof for future astronomy outings.  It might work for a Star Party but the chalets are very basic and the area around the chalets does not really lend itself to placing telescopes and I can also see the astrophotography people experiencing problems with power. I  think the chalets and the camping are too far apart to allow the groups to interact easily. I would, however, not rule the site out for Star Parties, as one could possibly overcome some of the perceived difficulties by negotiating with Wouter and Elsabé.

The rustic cottage could work for a small group with Dobbies, or even equipment that will run off batteries, which I am sure the owners would be more than happy to allow one to re-charge the next day.

The outside amenities at the guest house. Fortunately no longer  in use but the pines on the left lie to the south of the house and those in the background are to the west
The outside amenities at the guest house. Fortunately no longer in use but the pines on the left lie to the south of the house and those in the background are to the west
The back of the guest house as seen from the south east.  The pines to the west of the house can be seen in the background
The back of the guest house as seen from the south east. The pines to the west of the house can be seen in the background
This is Leeuwenboschfontein's "Eagles Nest"  to the North west of Kopbeenskloof. Where I intend spending a clear night with a telescope  some time in 2015.  Line of site distance from the guest house to there is about 10 km.
This is Leeuwenboschfontein’s “Eagles Nest” to the north west of Kopbeenskloof, where Lynnette and I intend spending a clear night with a telescope some time in 2015. Line of site distance from the guest house to there is about 10 km.

The guest house is a suitable site for doing astronomy and astrophotography but obviously only for small groups. There are some limitations as the house has tall pine trees on both the western and southern sides. The trees are about 25 m from the house but the area other side the trees is open so one can put a telescope there. The areas north and east of the house are open but the house then creates a high horizon to either the south or the west. The site is dark but unfortunately when we were there the weather was not good and we had partially cloudy weather on the first two nights and complete overcast on the third night. One aspect of the site that needs mentioning is the very noticeable sky glow from Worcester if there is even the slightest hint of cloud along the western horizon.

Sunset was quite spectacular and here one gets a good idea of how low the horizon on that side is
Sunset was quite spectacular and here one gets a good idea of how low the horizon on that side is
More sunset a little later on
More sunset a little later on
A single shot up at Scorpio
A single shot up at Scorpio
The sky glow from Worcester and De Doorns reflected against the low clouds
The sky glow from Worcester and De Doorns reflected against the low clouds at around 21:30
Venus and the moon in the dawn sky
Venus and the Moon in the dawn sky
Moon and Earth shine before dawn
Moon and Earth shine before dawn

Here are my Sky Quality Meter readings taken at the guest house on Kopbeenskloof.

Place: Kopbeenskloof Guesthouse
Locality & GPS: -33°35’53”, 19°57’27”, 1250m

Date: 26/05/2014
Time (SAST): 00:10
Temp (°C): 11.00
Comments: (Z)
Average (10) (MSAS): 21.21
StdDev (MSAS): 0.034705
NELM (V mags): 6.2298

Date: 26/05/2014
Time (SAST): 00:50
Temp (°C): 11.00
Comments: (Z)
Average (10) (MSAS): 21.17
StdDev (MSAS): 0.013333
NELM (V mags): 6.2102

Date: 27/05/2014
Time (SAST): 23:20
Temp (°C): 08.00
Comments: (Z)
Average (10) (MSAS): 21.37
StdDev (MSAS): 0.051034
NELM (V mags): 6.3152

Date: 27/05/2014
Time (SAST): 23:50
Temp (°C): 08.00
Comments: (Z)
Average (10) (MSAS): 21.42
StdDev (MSAS): 0.008498
NELM (V mags): 6.3408

I think one needs to get a group together, stay at the guest house, do some astronomy there and then take a decision on how suitable the site is. A summer visit might be our best bet.

Astronomy Recce in August 2014

The search continues for the perfect viewing site

Lynnette and I went off on another New Moon recce, looking for suitable venues at which to present either Southern Star Parties or Dark Sky events.  Our first port of call was a farm in the Touw’s River area which belongs to an acquaintance of ours. The owner is not amenable to the idea of allowing people onto the farm for astronomy or any other activity, for that matter. We would like, nevertheless, to share our astronomy experiences there.  The sky brightness reading was 21,53 MSAS.

Nikon D5100 VR 18-200mm F/3.5-5.6G ISO 6400 18 mm, 5s @ F/3.5
Nikon D5100
VR 18-200mm F/3.5-5.6G
ISO 6400
18 mm, 5s @ F/3.5
Nikon D5100 VR 18-200mm F/3.5-5.6G ISO 6400 18 mm, 10s @ F/3.5
Nikon D5100
VR 18-200mm F/3.5-5.6G
ISO 6400
18 mm, 10s @ F/3.5

Our next stop was Marion Maclean’s place in the Montagu area. She is situated in the same area as Bergwater Lodge but closer to the R318 and a bit further North at just over 400 m above sea level..  Marion has a spare room with a separate entrance that will sleep three and, at a push, four. You share her bathroom and kitchen but bear in mind she does not have a freezer, electric kettle or microwave and all cooking is on gas. Marion has expressed interest in having one or two people at a time there for Astronomy and also anyone interested in hiking, walking, birds, plants, insects, reptiles and small mammals – Evan take note. The average sky brightness reading there was 21,52 MSAS.

Marion's house, with the stoep and the spare room on the right facing you
Marion’s house, with the stoep and the spare room on the right facing you.  The sun set directly over that bush next to the carport’s pole, just to the left of the house.
The Vito and Marion's car. Note the angel of the yard sloping away from the house
The Vito and Marion’s car. Note the angel of the yard sloping away from the house.  Yhe sun set in the saddle between the two small peaks at the head of the valley.
A spooky panoramic shot of the house and surroundings
A spooky panoramic shot of the house and surroundings

Marion’s place is certainly dark enough for Astronomy and, I think in particular for astrophotography. There might be a problem with the horizon, as that is quite high to the West and North. Astrophotographers can set up on the stoep right outside their room from where they have an excellent view from East, through South and round to South-West all the way up to the zenith. I do, however, doubt if more than two people could setup in the space available there.  You could certainly set up a telescope on a tripod in front of and away from the house, but the surface is not level and setting up a Dobby there would present one with major problems.

Early morning view South from the stoep
Early morning view South from the stoep

We still have to negotiate the terms on which Marion is prepared to make her place available and, when that’s done, we will let everyone know. In the meantime, just take note that the place has potential for very small groups of astronomers.

The two other venues that we have already visited that might be suitable are Leeuwenboschfontein (average sky brightness reading 21,29 MSAS) and Kopbeenskloof (average sky brightness reading 21,29 MSAS) , both situated over 900 m above sea level.  We intend organizing a visit to both these venues for interested parties at a date in the not too far distant future so I won’t say much more about them now.

For purposes of comparison the sky brightness reading at Kati’s Wine farm was 21,20 MSAS. My value for Night Sky is 21,58 MSAS and 21,54 MSAS for Bergwater.

Autumn Southern Star Party from April 25th to April 28th 2014

Night Sky Caravan Park, Oudekraal, Bonnievale (-33.012486, 19.994881& 207m)

To start with, a special word of thanks to the sponsors, speakers, newcomers, day visitors and of course the regulars who helped to make the event possible. If you want to read some feedback from people who attended the Star Party please go here.

Sponsors:
Andrie van der Linde, Eridanus Optics,
http://www.eridanusoptics.com/store

Anneliese Carstens, Bonnievale Verhurings, Gelukshoop,
marankis@lando.co.za

Gesina de Wet, Oudekraal, Bonnievale,
nightsky@breede.co.za

SAASTA, South African Agency for Science and Technology Advancement,
http://www.saasta.ac.za

Waltons – Stellenbosch,
http://www.waltons.co.za

Donors
Alan & Rose Cassells – the two lights for the interior of the marquee.

Speakers (in order of appearance)
Martin Lyons – “Live Video Astronomy Demo”
Kos Coroniaos – “Amateur Astronomy in South Africa”
Martin Lyons – “Basic Spectroscopic Astronomy”
Lia Labuschagne – “Brown Dwarfs”
Alan Cassels – “Comfortable observing – Moving the Beast”
Auke Slotegraaf – “Photometry with a DSLR Camera”
Kechil Kirkham – “The SKA – The story so far”
Kerry Patterson – “Planetary Models of Hu Aquarii”
Brett du Preez – “Collimating a Newtonian Reflector Telescope”

Newcomers
Dwayne Engelbrecht, Lia Labuschagne, Charmaine Pretorius, Anneke Steyn, Bernie, Michelle & Keagan Swanepoel, Gerhard Vermeulen and Wendy Vermeulen

Day visitors
Anneliese & Tertius Carstens, Willie Lombard & Elise, Inus & Elsophie van Staden

The “old hands”
Alan & Rose Cassells, Charl and Yolandi Cater, Kos Coronaios, Brett du Preez, Wim Filmalter, Iain Finlay, Kechil Kirkham, Martin Lyons, Kerry Paterson, John Richards, Leslie Rose, Auke Slotegraaf, Willem van Zyl, and of course Lynnette and myself.

The 2014 Autumn Southern Star Parties Group Photo
The 2014 Autumn Southern Star Parties Group Photo

Lynnette, Snorre the cat and I got off to a very early start in Brackenfell and arrived at Night Sky by about 09:30 on Thursday.  Alan and Rose were already settled in and shortly after 10:00 Anneliese Carstens of Bonnievale Verhuurings and her two assistants were on site to pitch the marquee tent.  The whole process took just over 70 minute.  As soon as that was done,  we started putting up the banners and posters and doing all the other essentials to get the inside organized.  Alan and Rose pitched in to help with this and without their very able assistance, the job would have taken a great deal longer.  Thanks guys, as usual your convivial company made an otherwise boring task seem quite fun. Lynnette got the Admin table sorted out, as well as the chairs in the main tent and the coffee bar at the back of the tent.

The banner displayed at the entrance to Night Sky Caravan Park dates back to a 2004 astronomy outreach programme
The banner we displayed at the entrance to Night Sky Caravan Park dates back to a 2004 astronomy outreach programme
The side of the marquee tent facing the main camp area
The side of the marquee tent facing the main camp area
The left side of the tent's interior with the Admin Table on the left.
The left side of the tent’s interior with the Admin Table on the left.
The right side of the tent's interior.  The Sale Table is hidden by the chairs on the right.  All banners, inside and outside the tent, were designed by Auke.
The right side of the tent’s interior. The Sale Table is hidden by the chairs on the right. All banners, inside and outside the tent, were designed by Auke.
The Coffee Table was open all day and all night
The Coffee Table was open all day and all night
The Sale Table later sported binoculars and eyepieces put up for sale by various attendees.
The Sale Table later sported binoculars and eyepieces put up for sale by various attendees.

 

Lynnette at the Admin Table
Lynnette at the Admin Table

Thursday evening didn’t offer much by way of stargazing as it was one of those evenings where the clouds opened up and, just as one thought it was telescope time, they closed in again. Somewhere between 02:00 and 03:00 I got up to have a peek and it was totally clear, but I was too lazy to take the telescopes outside.

During the course of Friday most of the others trickled in, but by sunset there were still people on the list who had not turned up so we decided to move the Pub Quiz forward to the Saturday.

The weather looked indecisive about being cloudy or not, so we socialized and had an uncharacteristically late braai while Martin Lyons started setting up for his live video astronomy demonstration. Unfortunately the electronic gremlins were out in force and even with the able assistance of Kos Coraniaos the system obstinately refused to perform to expectations. As the clouds had cleared up we all dispersed to the telescopes and spent the rest of the evening observing or introducing the newcomers to the wonders of the night sky.

John, Alan & Leslie around the braai fires
John, Alan & Leslie around the braai fires
Paul, Alan, part of the camp and the marquee looking almost due South
Paul, Alan, part of the camp and the marquee looking almost due south
Evening reflection looking south-east
Evening reflection looking south-east
Alan point out a UFO to Paul, or maybe an early star?
Alan pointing out a UFO to Paul, or maybe an early star?

On Saturday Kos kicked off the programme followed by Lia in Martin’s vacant slot. The planned braai turned into a bit of a fiasco, because it started raining quite heavily just as the fires got going nicely. Kos and Wim’s attempts to rescue one of the fires by putting the braai drum on Brett and Leslie’s stoep, had unexpected consequences. Despite the fact that they closed the doors and windows the smoke from the fire still got into the house and tainted everything with a distinct “wood smoke” odour.

I am going to get myself a camera with a CCD this wide
I am going to get myself a camera with a CCD this wide
Leslie, Brett & Wenday at Kos's talk
Leslie, Brett, Wendy, Charmain & Gerhard at Kos’s talk
Lia concentrating on Brown Dwarfs
Lia concentrating on Brown Dwarfs
Reflections on the dam of the rain that was to follow shortly afterwards
Reflections on the dam of the rain that was to follow shortly afterwards

Even though Martin’s talk had been cancelled as a result of his equipment failure, leaving an open slot for an extended lunch, the braai was so late that Alan had to wait for people to finish eating before he could start his talk.  After Alan’s talk, Auke presented Alan with his long-awaited observing certificate and a special t-shirt commemorating his acquisition of a 12-inch telescope.  After that ceremony we took the group photo and set ourselves up for the Pub Quiz after supper.

Alan maneuvering The Beast into position
Alan maneuvering The Beast into position
Alan's ingenious drawing table
Alan’s ingenious drawing table
Auke handing over Alan's observing certificate
Auke handing over Alan’s observing certificate
Alan and the long overdue observing certificate
Alan and the long overdue observing certificate
Alan receiving his 12-inch t-shirt
Alan receiving his 12-inch t-shirt
Leslie & Auke enjoying the sunshine after the rain while the braai fires got going again
Leslie & Auke enjoying the sunshine after the rain while the braai fires got going again
Gesina after delivering the SSP-cake
Gesina, after delivering the Southern Star Party cake
Auke and Gesina in a congenial mood
Auke and Gesina in a congenial mood

The Pub Quiz was contended between six teams. After the first three rounds, three teams were eliminated leaving three to contest the next four rounds before Lia and John’s team made it through to the finals. It was a tight race between these two teams until John’s team took the lead. By that time the weather had cleared completely leaving everyone itching to get to the telescopes, so this year’s Quiz, like the Spring SSP in 2013, was not taken to the individual level. Probably a good thing because John has already won the Quiz twice before on an individual basis!

A rainbow at night is a shepherd's delight or something to that effect
A rainbow at night is a shepherd’s delight or something to that effect
With the clouds looking as if they were clearing people hastily started setting up so that they could start observing after the Pub Quiz
With the clouds looking as if they were clearing people hastily started setting up so that they could start observing after the Pub Quiz
Richard, Charl and Yolandi have spotted something interesting in the evening sky
Richard, Charl and Yolandi have spotted something interesting in the evening sky
Wim is also looking but Yolandi seems to be be worrying about the photographer
Wim is also looking but Yolandi seems to be be worrying about the photographer
Al set up and ready to fire off the first salvo in the Autumn 2014 Pub Quiz
All set up and ready to fire off the first salvo in the Autumn 2014 Southern Star Pub Quiz
The final rounds and on my left gaining steadily, John's team
The final rounds and on my left gaining steadily, John’s team
The final rounds and on my right, putting up a brave fight to stay in the lead, Lia's team team
The final rounds and on my right, putting up a brave fight to stay in the lead, Lia’s team
The winners of the Autumn 2014 Southern Star Pub Quiz. Bernie Swanepoel, Muchelle Swanepoel, Iain Finlay, John Richards and Keagan Swanepole.  Keagan is wearing the coveted Southern Star Party Pub Quiz Floating Rosette
The winners of the Autumn 2014 Southern Star Pub Quiz. Bernie Swanepoel, Michelle Swanepoel, Iain Finlay, John Richards and Keagan Swanepoel. Keagan is wearing the coveted Southern Star Party Pub Quiz Floating Rosette

For the evening and late-night coffee we had a very nice cake baked by Gesina to commemorate the seventh Southern Star Party.  The cake was iced in blue and decorated with silver stars.  The cake also served to celebrate John Richard’s 70th birthday and we wish him well on his next 100 years.  A very nice gesture indeed, thanks Lynnette.

The Southern Star Parties Cake commemorating seven Star parties (and John's birthday)
The Southern Star Parties Cake commemorating seven Southern Star Parties (and John’s birthday this time too)

Sunday’s day-programme went off without a hitch. Auke had to leave just after his talk to get Kos back to Somerset West and then he unfortunately encountered a problem and was unable to return as planned. By evening the sky was clouded over, much to everyone’s disappointment, so we also cancelled the scheduled “Ethno-What’s up Tonight”. Anneliese and Tertius had come over specially for the stars, so it was a great disappointment for them.  However, just as we were sitting down having coffee with them, Leslie knocked on the door and announced that the clouds were clearing so we could set up a telescope and take them on a tour. Before midnight Lynnette and I gave up the unequal battle with the dew and went to bed.

Auke seated, left back talking about photometry with a DSLR camera
Auke seated, left back talking about photometry with a DSLR camera
Kechil talking about the SKA after having shown us how to dance the SKA!
Kechil talking about the SKA after having shown us how to dance the SKA!
Kerry explaining the intricacies of HU Aquarii
Kerry explaining the intricacies of HU Aquarii
Brett explaining exactly why most of us avoid collimating our telescopes
Brett explaining exactly why most of us avoid collimating our telescopes
The sunset was absolutely magnificent
The sunset was absolutely magnificent
Much later we could actually do some stargazing on an absolutely windless night as evidenced by the reflections in the dam
Much later we could actually do some stargazing on an absolutely windless night as evidenced by the reflections in the dam
Over on the far side of the dam a moving red light is reflected in the water
Over on the far side of the dam a moving red light is reflected in the water
The Magellanic Clouds, 47 Tuc, the Tarantula very faintly and a tiny corner of the Milky Way
The Magellanic Clouds, 47 Tuc, the Tarantula very faintly and a tiny corner of the Milky Way

On Monday morning everyone was packing up and saying goodbyes. In-between all the farewells, we took down the posters and banners in the tent, folded up tables, stacked chairs and loaded the trailer. By that evening it was only Lynnette, Snorre, myself and Iain and Willem left.

On Tuesday morning with the clouds building up, Anneliese and her crew arrived to take down the marquee.  Iain and Willem were also packing up and when Anneliese and her crew had finished one of her crew remarked, “Look at those two still struggling with that little tent and we’ve already finished with the big one.”  Iain and Willem did eventually finish and left shortly after midday.  Lynnette and Snorre and I stayed till Wednesday before we left for home via the Pitkos Farm Stall.  Regrettably they had no more roosterkoek by the time we got there so we just had coffee and bought a box of Nuy Muscadel for the next SSP in October 2014 before heading home!

This table gives the sky brightness readings obtained during the Autumn 2014 Southern Star Party.

Place Night Sky Caravan Park Night Sky Caravan Park Night Sky Caravan Park Night Sky Caravan Park Night Sky Caravan Park Night Sky Caravan Park
Locality & GPS -33°00’44.95″, 19°59’41.57″, 207m -33°00’44.95″, 19°59’41.57″, 207m -33°00’44.95″, 19°59’41.57″, 207m -33°00’44.95″, 19°59’41.57″, 207m -33°00’44.95″, 19°59’41.57″, 207m -33°00’44.95″, 19°59’41.57″, 207m
Date 24/03/2014 25/03/2014 26/03/2014 27/03/2014 28/03/2014 29/03/2014
Time (SAST) 22:30 23:30 22:00 22:00 22:00 22:00
Temp (°C) 18.00 17.00 16.00 16.00 16.00 17.00
SQM1 21.68 21.58 21.61 21.67 21.59 21.65
SQM2 21.65 21.57 21.62 21.67 21.60 21.64
SQM3 21.66 21.56 21.62 21.66 21.61 21.65
SQM4 21.64 21.59 21.63 21.66 21.60 21.64
SQM5 21.65 21.58 21.60 21.67 21.61 21.64
SQM6 21.63 21.56 21.61 21.68 21.60 21.64
SQM7 21.65 21.58 21.61 21.67 21.59 21.61
SQM8 21.66 21.56 21.62 21.67 21.59 21.64
SQM9 21.65 21.55 21.61 21.66 21.60 21.63
SQM10 21.66 21.58 21.61 21.66 21.60 21.65
Average (MSAS) 21.65 21.57 21.61 21.67 21.60 21.64
StdDev (MSAS) 0.012689 0.012207 0.008000 0.006403 0.007000 0.011358
Med.(MSAS) 21.65 21.58 21.61 21.67 21.60 21.64
NELM (V mags) 6.4610 6.4203 6.4418 6.4679 6.4343 6.4541

DarkSky Weekend at Bergwater Lodge, Pietersfontein, Montagu

DarkSky Weekend at Bergwater Lodge, Pietersfontein, Montagu:  26th February to 02nd March 2014

26th of February
Lynnette, Snorre the cat and I left home in the Vito on Wednesday the 26th of February hoping to get in at least one extra night’s observing at Bergwater Lodge. On the way there we stopped off at the Pitkos Farm Stall to buy ripe figs and at Pinto’s Butchery in in Paul Kruger Street in Robertson to buy cheese grillers.  In Montagu we stopped off at Marina le Roux the vet’s surgery for Snorre’s annual check-up, which he passed with flying colours and then on to Bergwater.  It was hot when we left home and even hotter when we arrived at Bergwater Lodge.  After unloading and storing everything away we relaxed and waited to see what the weather would do in the evening.  The weather turned out to be superb for stargazing, crystal clear and the upper atmosphere nice and stable.  At 02:00 the average of 20 sky brightness readings, taken with a Sky Quality meter, was 21,6395 magnitudes per square arcsecond (MPSAS) which translates to a naked eye limiting magnitude (NELM) of  6,4544 V mags. By 04:00 we were falling over our own feet so we packed it in and went to bed.

27th of February
On Thursday Jannie and Eddie Nijeboer, who are old hands at Bergwater, arrived during the course of the afternoon and settled in.  Thursday evening started out very nicely and then, shortly after 22:00 the clouds moved in.  By 01:00 it was completely overcast and we decided it was not going to clear so we all went off to bed.

28th of February
Friday dawned bright and clear but day still ended up being very hot.  The rest of the group slowly trickled in. Wendy Cooper (Secretary of the South Peninsula Astronomy Club) arrived in good time followed by a first timer at Bergwater, John Richards (a long standing member of the Cape Centre), Ralph and Sheila Baker (novice stargazers and guests of Jannie and Eddy) also arrived with daylight to spare.  The rest, Martin Coetzee (Orion Observation Group), Lia Labuschagne, (Chair of ASSA’s (Astronomical Society of Southern Africa) Cape Center), Wendy Vermeulen (Cape Center member) and Brett du Preez (astrophotographer of considerable repute –  see the cover of the 2014 SkyGuide), all arrived after dark.

Lia and Wendy, in keeping with the well-established tradition at Bergwater, went sightseeing after dark up to Doringkloof.  We did not know about their intention to recce the area so Martin kindly drove me back to the R318 to try and contact them but without any success.  We returned to Bergwater hoping they were not in trouble and were quite relieved when they arrived shortly afterwards.

Auke Slotegraaf could not make it due to family complications and was missed by all.  Henry Oliver, Jaco Wiese and Raoul Schwenke, were due to arrive on the Saturday as Henry still had teaching commitments in Wellington.

Friday night started out with some instability in the upper air but that improved as the night progressed.  By midnight conditions were really good.  At around 04:00 on Saturday morning I managed, much to Brett’s amusement, to identify the rising Venus as a plane with its landing lights on or, alternatively, as a possible Alien UFO!  At 01:00 the average of 30 sky brightness readings was 21,7023 MPSAS which translates to a NELM of  6,4851 V mags. The serious observers got to bed well after 04:00 so none of them were about much before 11:00 on Saturday.

DSC_5873_Bergwater_01Mrt2014_Venus
Venus when I first spotted it and thought up all the fancifull explanations about what it was and was not
DSC_5887_Bergwater_01Mrt2014_Venus
Venus a short while later after the penny had dropped

1st of March
Saturday was another scorcher but after rising fairly late many of the group members took the opportunity to cool off in the swimming pool.  Brett set up his binoculars with solar filters so that everyone could look at the sunspots during the course of the day.  With Brett’s help I also managed to take a more or less reasonable photograph of the Sun later in the afternoon.

DSC_5910_Bergwater_01Mrt2014_Dagaktiwiteite
Martin and Sheila digging into some watermelon to combat the heat
DSC_5909
Brett, Martin & Eddy taking it easy in the shade

 

DSC_5908
This is not Eddies midday snooze he is looking at the sunspots through Brett’s binoculars equipped with sunfilters

 

DSC_5905
Sundry telescopes and Auke’s impressive banner depicting the Universe in six informative panels
DSC_5904
Where have all the people gone, gone to cooler spots every one ….
DSC_5903
Martin taking up position for a sunspot viewing session while Brett, Eddy, Jannie & Sheila look on. In the background is a glimpse of the magnificent scenery at the Bergwater Lodge
DSC_5900
Martin heading for the shade and Brett at the binoculars. The high level clouds in the background eventually went away
DSC_5917_Bergwater_01Mrt2014_Son
My image of the Sun. Thanks Brett.

By the time it was completely dark Henry, Jaco and Raoul had not turned up and it later materialized that Jaco’s wife Jacoleen, who is pregnant, had been admitted to an ICU for observation. The rest of the night was perfect for viewing.  Brett eventually sorted out the problem with his equipment – a too long connection cable.  As he did not have a shorter cable there, he did the next best thing and switched to binocular observation, as he had done on the previous evening.  At 11:00 the average of 30 sky brightness readings was 21,5970 MPSAS which translates to a NELM of  6,4333 V mags.  Lynnette and I only got to bed well after 04:00.

Telescope activities
An animated GIF depicting some of the action around the telescopes at night

2nd of March
At around 05:00 on Sunday morning the power went off, not only at the Lodge, but in the entire valley.  Apparently ESKOM was carrying out scheduled maintenance but somehow the Lodge had not been notified.  This caused special problems at the Lodge because it put the pumps that supply the Lodge with water out of action which meant that, when the toilets had been used once, the cisterns did not refill.  The power only came back on after 17:00 that afternoon.

The power outage and associated water problem meant that nobody could prepare breakfast so most people left earlier than usual to have breakfast in Montagu or Robertson.  Lynnette and I relaxed for the rest of the day and made our preparations for the guests we expected for the stargazing event on Sunday evening.