Observing Report 25 May

26 05 2012

We tried out Howson Oval for the first time on a cold and windy night, so it was probably the worst weather we would experience there, as it is exposed. Unfortunately, it was only me and Jenny, a visitor joining NSAS, so we persevered for several hours and gave up at 8 PM, when it was clear everyone else stuck their heads out their doors and decided to stay in front of the fire.

Howson Oval is a great observing site, far superior to NTGC, once we do a deal with the Council about access to the security lights on the dressing shed. There are no streetlights visible, and the only lights on the horizon are The San to the north, but even that is hidden. We could see near the horizon for 360 degrees from the middle of the oval, and while not as good to the north as Golden Julilee, it’s not bad. Even better, the toilets were unlocked! (probably Council security forgot them). We’ll give Howson a go again on a better night.





Observing is On tonight 25 May at Howson Oval

25 05 2012

Observing is ON tonight at Howson Oval, Turramurra (see previous post for directions). IT IS NOT AT NORTH TURRAMURRA GOLF CLUB. Someone will be there at 6 PM. It could be a short session due to forecast cloud later.





Observing report for 18th May 2012

21 05 2012

 Three members and four visitors attended the observing site at North Turramurra with 5 different scopes. Despite some initial concerns about bushfire smoke from hazard reduction burns to our east the evening turned out to be very good for viewing. The smell of burnt eucalyptus soon passed.

The Jewel Box, Omega Centauri and Eta Carina nebula were popular targets as the scopes adapted to the conditions and gave an indication of the seeing to some.

With Scorpius, Sagittarius, Ophiuchus, Serpens and Ara rising in the East many globular and open clusters and nebula were observed including, M4, M6, M7, M8, M10, M12, M20, M22, M28, M54, M80 and NGC6397. M53 in Coma Berenices and the planetary nebula NGC4361 in Corvus were also observed.

Given the conditions Geoff’s 16″ dosonsian was put to good use tracking down galaxies in Leo and Virgo. I quickly lost count of those that were observed as the scope moved on from one galaxy to the next. It was the highlight of the evening and only a few galaxies evaded us. M49 and most of the Markians Chain of Galaxies in Virgo were worthy of a mention.

Seeing to Saturn was good too with the Cassini division being observed in the 16″ dob. A little dew slowed a few of us towards the end but otherwise a successful evening.

Tim Herridge





Observing this Friday the 25th

21 05 2012

If Observing goes ahead this Friday the 25th, we will try out Howson Oval, Turramurra, which can be found on Google Maps by inserting these coordinates: -33.741275,151.107565

Howson Oval is off Howson Avenue, is a large cricket pitch with no streetlighting, and minimal security lights. You will have to move your scope from the parking lot to the middle of the oval, about 25m, but level. PLEASE BE CAREFUL WHEN TURNING INTO HOWSON AVE FROM THE SOUTH, AND DON’T MAKE A RIGHT TURN TO THE NORTH WHEN LEAVING IT (turn left and make the first right, and do a U-turn). This a very blind intersection on Comenarra Parkway. Look for the On/Not on Friday afternoon. Since we’ve already had two Observing sessions in May, we won’t back up this one to the Saturday.





Observing Friday 18 May 2012 is ON

18 05 2012

Observing in on this evening at North Turramurra Golf Course and the gates will be open from about 5:15pm. There may be a little smoke from Hazard Reduction burns in the Sydney area but the sky should otherwise be clear.

The sun sets at about 5;00pm. Here is a link to a map showing the location:

http://nsas.org.au/contact/north-turramurra-golf-club/

Tim





Observing report for 11th May 2012

12 05 2012

With the weather quite balmy, and clear skies, about a dozen lucky observers descended upon North Turramurra Golf Course for a pleasant night’s observing.   The dobsonian was king, with all standard sizes being represented, ranging from 6 inches, through 8, 10, 12 up to 16 inches, the latter with two fine examples.    The 8 incher was a shiny brand new scope and help was given by NSAS members to get the finder scope aligned and to point out some of the main targets in the sky at this time of year.  One of the 16s arrived in a sedan and it was intriguing to see its large base being assembled from a flat packed state then later on disassembled and packed back in the car.  Pete’s 12″ goto dob kept disconcertingly slewing to things even though no-one was anywhere near it, but it was really just Pete showing off his Ipad/SkyFi system from 10 metres away.

A good range of objects were observed, from the usual suspects such as Orion Nebula (for the early arrivals only), Mars, Saturn, Omega Centauri, the Jewel Box, and Eta Carina; a few planetary nebula such as the Blue Planetary, the Ghost of Jupiter, and the Bug Nebula; globular clusters such as M22, M28, M4; some open clusters such as M7; galaxies such as the Leo Triplet (M65, M66 and a fairly faint NGC 3628 seen using averted imagination), the Sombrero (M104), and some members of Markarian’s chain of Galaxies including M84 and M86, plus many other objects too numerous to mention or remember.  Some time (probably too long) was spent in a fruitless attempt to see the Dark Doodad Nebula near Musca, purely because we liked its name.

About half the observers were visitors, so there was a fair bit of chatting going on about scopes and observing, and comparing gear.  Chris was doing a good job telling the visitors about NSAS’s activities.

The seeing was pretty good and we had a fun time at the end of the evening viewing Saturn through all the scopes.  We could pick out the four moons Titan, Dione, Tethys and Rhea in the eyepiece, as well as the Cassini Division and some cloud banding on the planet.

All in all a very enjoyable evening.

Gary Maass





Observing Friday 11th May is ON

11 05 2012

We have had a nice break in the clouds this afternoon.
Therefore observing tonight (Friday 11th May) is ON!

The location is North Turramurra Golf Club.
There is a map here:

http://nsas.org.au/contact/north-turramurra-golf-club/

The Sun sets around 5 pm.

I will aim to be there at 5:15 pm.

Gary Maass





Transit of Venus Viewing at Practically No Cost

5 05 2012

REWRITTEN FROM THE WEBSITE:

——————————————————————————–
Subject: Transit viewing at practically no cost

I have read about a scheme that was used successfully to view an eclipse. A large wall was in complete shade and a notice invited passers-by who had a hand mirror to stand in the sunlight and reflect the light onto the wall. I do not know how far they would be from the wall but the reflection was close enough to see the progress stage of the eclipse. It is like re-inventing a pinhole camera and decreasing the effects of diffraction at the same time as the “source” is much larger than a pinhole.

My comments on the situation:

What is a pinhole camera? Basically it is a device for getting some light into a dark space with the proviso that the source of the light is small. Being a pinhole in a card does not change the nature of the sunlight so the source does not have to be a hole in something; it can be a small flat mirror or a larger one with most of the surface covered with black plastic adhesive tape and what’s more it would not even have to be circular as long as it is small – see next paragraph. You do not even need a box – you can use a darkened room which has a small conveniently-placed window or even a doorway for the projected beam and the screen can be a wall or a sheet of something with pale colouring inside the room. There is a drawback of course – you might need a distance of 20 to 30 metres from mirror to screen so you may have trouble finding a suitable place for the mirror as the Sun’s position changes unless you have an assistant with a larger flat mirror which puts another part into the light path. Once you find a suitable spot for the small mirror, direct the sunlight from the larger mirror to the smaller one. As time progresses, only the larger mirror would need to be adjusted by tilting it so I guess that the assistant would not be able to view the screen and would need to be relieved now and then to see the progress. The viewers would be inside the darkened room out of the light path.

Is it part of your experience during a partial eclipse [or at least during a partial phase] that you were under a tree, each small gap in the foliage, each with its own shape, produced, on plain ground, a useful picture of the partly covered Sun? In my youth, we had an old garage whose roof was recycled corrugated iron containing many (unoccupied) nail holes . In effect, the old garage was a batch of pinhole cameras. Every hole gave us a very good picture of the eclipse projected on the floor which most certainly was not white or even light coloured and the holes were only reasonably close to circular. This works for the tree because the size of the gap in the foliage is small compared with the distance from the gap to the ground. Here lies the reason that the small mirror in the scheme above does not even need to be round. The passers-by (above) would have had mostly rectangular mirrors. I have not yet tested this projection method so I cannot predict a good size of mirror but I expect that a diameter of 1.5 to two centimetres at 20 to 30 metres should be a starting point.

All sorts of variations are possible. e.g., masking a rear vision screen:
Remove top and bottom of a carton and put a light paper over one of the open parts. Face the other opening towards the mirror so that the box and screen are in the darkened room and viewing is from behind.

Bob Roeth NSAS





NSAS Events for May

3 05 2012

In May we start out with the Theory Group next Tuesday the 8th, at 7:45 PM, and the General Meeting will be Tuesday the 15th at 7:30 PM. Our speaker for the month is Michael Ireland from Macquarie Uni Physics Dept, who will be speaking to us about SUSI, the optical inferometer at Narribri. Observing this month (and the weather looks better) is a bumper crop, with the Fridays 11th, 18th, and 25th, so surely we can manage one night! All meetings are at Regis Hall, St. Ignatius, and visitors are welcome, as usual.





Observing is ON tonight 13 Apr

13 04 2012

Observing is ON tonight at North Turramurra GC. Someone from NSAS will be there from 6:30 PM. Visitors welcome, as usual.








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