Posts Made By: Anthony Allsobrook

I have been itching to buy a small apo for several years, and recently I decided to take the plunge. The TMB80/600 arrived on Thursday and after two cloudy nights, Saturday was the first opportunity to try it out. At 10 pm the sky was totally overcast, but by 3 am Sunday morning the cloud was gone. The TMB requires a modification to the dovetail plate in order to mount it onto my Vixen SP GEM. Being impatient for a quick look, I used a "beanbag" atop a very solid Linhof tripod as a makeshift support in true ATM style.

I used only one eyepiece, Zeiss 30 mm 2" wide-field 70° AFOV giving 20X magnification. Being limited to such a low magnification I went for several easy clusters, two globular clusters and a few easy double stars.

I have never observed at 20X with an 80 mm Super Apochromat before and this was a revelation. Pleiades and Hyades were both splendid. I looked for nebulosity around Merope, but didn’t see any. I’ll try again from a dark sky site and when there is less haze.
M42 was very easy to see and the Trapezium could be just made out at 20X. All these are familiar targets for northern observers, so I'll limit most of my comments to our southern skies.

NGC3372 Key-hole nebula surrounding Eta Carinae. This nebula is 5X the size of M42 and just as easy to see. It is cut in two by a massive dark lane which was also very easy to see. Wonderful sight at 20X.

NGC3532 in Carina. I just stared and stared at this massive cluster in disbelief. I have observed it many times before, but I have never seen it like this. It looks SO different at 20X with a wide-field eyepiece. In Burnham’s there is a photo on page 474 and a description on page 475. Quote: "Pickering found it by far the finest irregular cluster in the sky" and "Sir John Herschel considered it the most brilliant he had ever seen". All I can say is that as I moved to other objects, I kept coming back to NGC3532 for yet another look. I just couldn’t keep my eyes off it. Furthermore, the cluster is in an area which is awash with stars, making it doubly spectacular at low magnification. Mostly blue/white stars and a few orange stars. Sky Atlas 2000 has 6 stars with double star tick marks, so I’ll be coming back as soon as I can use high power.

NGC4755 The Kappa Crucis "Jewel Box". The brighter stars are all B-stars and there is one orange M2 supergiant near the centre. I have viewed this object many times of course, but at 20X it looked like a splendid miniature ... tiny needle-point stars.

NGC2516 in Carina. This splendid cluster has 3 double stars with a fourth double just outside the cluster ... all to be revisited later at high magnification.

I also observed two easy globular clusters. NGC5139 Omega Centauri appeared as a cloudy patch of fairly uniform brightness, and then tapering off towards the edge. No resolution into stars.
NGC104 47 Tucanae had a totally different appearance, highlighted by the low magnification. Much brighter in the centre with a comet like condensation.

The LMC was at upper culmination but too close to the zenith! I was not game to tilt the TMB80 to such a crazy angle on the bean bag, so LMC will have to wait. Besides, it was too hazy for faint fuzzies.

I was finally driven indoors by the brightening dawn. What a night! I had hoped that the TMB80 Super Apochromat would become my favourite ‘scope, and first indications are that it will.

I have posted the double star observations on the doubles forum.

Anthony
Wellington NZ @ 41°S 175°E

I've just received a TMB80/600!!! This is one SOLID wee telescope with Feathertouch focuser. I've only had it out once and already I just LOVE it!!! (I've posted some quick notes on DSO and Doubles Forums)

If you have the same scope I would like to hear about which eyepieces work particularly well. I'm interested in most areas - double stars, DSOs, planetary and moon. I will be using both alt-az and motorised GEM.

Example. Since I have a motorised GEM I don't have a need for wide angle EP for viewing faint fuzzies. But what EP works best with this telescope to make these objects visible?

Thanks
Anthony

A friend has a Meade 8" LX200 with UHTC coatings, or so the label on the tube says. However, the coating looks somewhat PURPLE to me ... I expected a GREEN(ish) color as one sees on multicoated camera lenses ( Example Pentax SMC ).

The ring around the corrector plate just says "ULTRA-HIGH CONTRAST" and not UHTC!!!

This has probably been discussed here before, but I don't remember seeing a thread. Can anyone explain please??

Thanks in advance.

Anthony

ATMers

Who makes the finest Newtonian secondaries in the 3.1" (ish) size?

Thanks in advance

Anthony

After a week of cold southerlies and rain, last night was beautifully clear. While walking up to the house I noticed that Jupiter about to crash into the moon. It was something I wasn't expecting and came as a very pleasant surprise. The 80 mm was hurriedly set up and I glued my eye to the eyepiece as Jupiter was slowly occulted by the moon. The mountainous nature of the edge of the moon was clearly visible. Nice!

But it all happened just too fast. Thinking about it afterwards, I wish I had been more observant regarding the occultations of the moons of Jupiter. In the occultation of stars by the moon, the star is extinguised more or less instantaneously, at least as seen by the human eye (notwithstanding the ringing pattern produced by diffraction at the edge of the moon, which may be measured photometrically). But what happens with Jupiter's moons. They have a finite size which might result in them slowly fading from view. The rate of fade will of course depend on the angle at which they approach the surface. The more the angle approaches a graze, the longer the fade will be.

But is this so? Is the response of the human eye fast enough to see this? Has anyone out there observed this? If so I missed it ... next time I will be more observant. Anyone?

Anthony

I am trying to contact Mark Cowan of Obsidian Optics. Email bounces back. I posted a letter to his POBox but this was marked "BOX CLOSED" and returned by the Post Office. Can anyone help? My apologies in advance if this seems off topic - I thought this Forum would be the best place to ask.

Anthony
New Zealand

I have just received a mirror from Obsidian Optics ... fantastic workmanship from Mark Cowan! At home I will use it in a motorised equatorial mount for imaging, but I would also like to use it in a ultra light weight Dob style mount that can be taken along on Astro-Tourism expeditions. This 14 inch silica mirror weighs about 9 pounds so when I say ultra light weight mount, I really mean it.

I already have Kriege and Berry's Dob book. I also recall an article in S&T from a several few years back, so I need to dig it out. The author had made a very light weight Dob out of aluminium ... but Dob designs move on ...

Can anyone suggest where I can find some of the latest design ideas?

Thanks!

Anthony

Having read Inge's admonition on burnout, I thought I'd make a contribution ... it's totally off topic of course ... or is it ... wandering starry-eyed through the galaxy can't really be off topic on an astronomy forum, can it ...

well, gentle folks, it's like this ... while our poor Aussie cousins across the Tasman Sea have been struggling with heat waves and monstrous bush fires, here in New Zealand it's been a wet cool summer ... well not really summer ... but it's not cold either ... today we had a daytime high of 19°C and an overnight low of 13°C - typical of our summer that's still to arrive ... a maritime climate we like to call it ... but the cloud ... oh man ... the cloud ... the Maori name for New Zealand is Aotearoa which means "Land of the long white cloud" ... and this summer Aotearoa is living up to its name ...

So this evening just as dusk was falling, no point in hauling out the telescope ... instead I put on my tramping boots (hiking boots) and wandered down my long driveway and onto Akatea Road ... then along to Singers Road and within 5 minutes I was heading down the tar seal zig-zag walkway that leads steeply down the 700 foot hill to the Petone Railway Station ... a very beautiful walk through virgin native bush (bush is what we call the forest here) ... a path well lit by the glow of incandescent sodium ...

by the time I reached the bottom of the hill it was quite dark, but instead of returning up the hill via the main roadway, I got out the LED headlamp and ducked into the bush of Galbraith Gulley. By day this is a delightful wee stream that gurgles gently through the native bush ... trees, ferns, ancient tree ferns and mossy banks ... but remember it's 9.30 pm now and pitch dark in the bush ...

the track, if one can call it a track, crosses the stream about 30 times as one heads upstream towards the head-waters of the gulley ... and every few metres I stopped and turned off the LED headlamp ... and there I was ... enveloped by the galaxy ... the Galbraith Gulley Glow-worm Galaxy ... literally thousands of glow worms performing their glow worm mating thing on the banks of the stream ... it was like fairy-land ... and for half an hour I wandered slipping and sliding over the wet rocks in the dark as I headed up the stream ... now by the light of the red LED and now with the light turned off ... and all the while the glow worms glowed and the stream gurgled gently ...

but all too soon I broke out of the bush at the head of the gulley ... just 50 metres from my letter-box ... why did it have to end ... I can't help feeling so very lucky ... yes, this is Aotearoa, the land of the long white cloud ... but the clouds bring the rain and the rain feeds our ancient forests and our gentle streams ... it's the stuff that Paradise is made of ...

and so, gentle folks, it's off to bed, perchance to dream ... of drifting through the galaxy ... of countless stars without a name ... accompanied only by the sound of ones own heart beat and the gentle gurgle of the stream ...

another night the sky will be clear ... but tonight there was a different kind of magic ...

Anthony
Wellington, Aotearoa New Zealand at 41°S 175°E

Inge
I first learned about noctilucent clouds when I worked at a weather station more than 30 years ago. I have always looked out for them but I have never seen them from various places I have lived in the Southern Hemisphere from 34*S to 41*S. I have spent many summer holidays climbing and hiking in New Zealand's Southern Alps as far south as 45* and still I have never seen them!

Google will turn up very interesting websites if you type in "noctilucent clouds solar cycle". From the following website:
http://www.hamptonu.edu/science/physics/cas/aim/noctclouds.html
I found an interesting graph showing the relationship between the solar cycle and number of noctilucent clouds sighted. Reported by AIM team => Aeronomy of Ice in the Mesosphere.

And on this website
http://www.irf.se/MRIatmos/projects/nlc/
I found this:
"Noctilucent clouds seem to be increasing in occurrence (Gadsden, Journal of Atmospheric and Terrestrial Physics vol 52, p247, 1990) and some scientists believe this may be due to increased greenhouse gases in the atmosphere. The clouds also show an 11-year variation roughly opposite in phase to the Sun's activity cycle, ie thay are less often seen at solar maximum. It is not yet known how closely PMSE are related to noctilucent clouds (sometimes they have been seen together, sometimes not) , nor whether PMSE also vary with the solar cycle nor whether they are increasing on a longer time scale.

At present we are just past (?) the maximum in the solar cycle and this may be part of the reason why there are fewer clouds this year(?).

Perhaps Astromart readers in the deep south of South America may have seen them during the southern hemisphere's summer solstice (December-January).

Another website with interesting information is:
http://www.nlcnet.co.uk/
There are of course heaps of websites with stunning photographs of noctilucent clouds.

Anthony 41*S 175*E

Kevin

I thought you might enjoy this story.
A couple of days ago I read your "Venus" observations on ASTROMART and I thought "I'd like to observe that - but my Zeiss AS 80/1200 lens (newly acquired) is not yet a 'scope - it's just a lens cell.

Anyway, today while walking down Jackson Street, Petone (I'm sure you know this famous local NZ landmark) I saw a 2 metre long cardboard tube lying in the gutter. Walking past it I thought "That would make a nice telescope tube if only it weren't lying dirty in the gutter". As I went past I realised that it wasn't "dirty" - it looked "newish". Walking back I realised that it wasn't dirty at all and had probably only lain there a few hours at most - clean as a whistle. Glancing nonchalantly sideways to make sure that no-one was looking, I surreptitiously picked it up and continued down the footpath with it tucked firmly under my arm. To cut a long story short, it is now at home and guess what - it is less than 0.25 mm larger in diameter than the cell of the AS 80/1200 lens cell! ! ! ! ! Just about the thickness of a layer of paint. PERFECT.

So hopefully I will soon have a WORKING Zeiss AS 80/1200 just in time for viewing Venus. The focuser arrives next week (hopefully).

So thanks for the Venus thread.

Anthony (at 41 south)