Friday, January 11, 2008

Observing Session - 1/10/08

Last night we had decent clear skies. Seeing was only 2/5-3/5, but transparency was 4/5 and the sky dazzled with stars. We could also make out the Milky Way fairly well. I took my Lightbridge 12" up to the local observing spot, joined by Scott and his Astrophysics (AP) Traveler and Celestron C6.

Again, setup of the Lightbridge was a snap. I had the scope constructed and collimated in under 15 minutes (would have taken less time if I wasn't yapping my head off). I also used the Astrozap light shroud that I purchased with the scope, which helped get some extra contrast. I had several specific targets to hunt for last night, trying out my star-hopping technique and also trying to get used to the red dot finder that came with the scope.

I found all of my desired targets relatively easily. Notes below:

Comet Tuttle: Currently at about magnitude 5.9, the comet was located near the constellation of Cetus. I haven't learned Cetus yet (Goto scopes can make you lazy) but quickly determined its location and structure and was able to find the comet. A small fuzzball, not quite as bright as Comet Holmes but it had similar structure. I could see the nucleus and surrounding coma quite easily.

M81 & M82: This took me the most time to find. These two galaxies sit in a remote part of the sky so it can be like finding a needle in a haystack. I used the "pointers" in Ursa Major and Polaris to figure out approximately where they were, and after about ten minutes of hunting was able to find them. The view was very nice indeed. With the 22mm Panoptic, I was able to see both in the same field of view. M81 looked fine, but M82 (the side-on galaxy) was quite bright through the Lightbridge and rather striking. The nice contrast of this scope really helped.

M79: This is a small globular cluster near the constellation Lepus (yet another constellation I needed to learn last night!). Quite small but prominent, despite the fact it was low in the sky. I could barely see some individual stars within it, but pretty nonetheless.

M44: The Beehive Cluster. Very nice in the scope at very low power using the 1RPD 30mm (63X) eyepiece.

I also visited a few old friends that I typically visit during the winter; M42 (amazing last night, beautiful detail in the nebula and I could easily make out stars E and F within the Trapezium), M37, M31, M32, M110 and the Double Cluster.

I really need to get this scope out to the Canyon of the Eagles, where I think it will do wonders. Hopefully next month...

Equally impressive were the views through Scott's scopes. The C6 really packs a lot of punch for such a portable package. It revealed great detail in M42, and the Double Cluster and M37 looked fabulous as well. His AP Traveler (forget the size) also provided fantastic views of various objects. Talk about pinpoint sharp images! That scope would be an amazing choice for astrophotography.

One slight disappointment lately has been my purchase of the William Optics binoviewers. I bought them with the Lightbridge, hoping they would be compatible. However, I do not have enough back focus to bring images to focus with them. I also tried them out on my XT6 Dob, but to no avail. We tried them last night on the AP Traveler and wow, what a view! M42 was amazing, very 3D-like (the nebulosity seemed to appear in front of the stars in the nebula). So, I need to try and see if they will work with my LX200 soon, otherwise I'll need to send them back.

A great viewing experience last night!


astronut said...

Hi again Phil,
I've just read your observing report, excellent!!
With the Binoviewer you mentioned problems with the back focus.
I gather you mean racking the focuser outwards.
There are three sizes of extension tubes available for the price of $20-$50US, one of these will give you the amount of out focus needed to make the bino's work.

Phil said...

G'day there!
Well, actually I need more movement towards the diagonal mirror, not outwards. I can get close enough to be able to do a star test but just not close enough to get a sharply focused image. Some folks have told me to use shorter truss tubes but seeing as though they work a treat on my LX200, I'll just confine them to that scope.

Thanks again for visiting!

astronut said...

Hi Phil,
Good morning from a very wet Sydney.
The drought has finally broken this summer and with it no observing since the begining of December!!DOH!!
If you're desperate to use the bino's on the LB, there could be a way out.
How much in focus do you need for a sharp image?
Wind the primary collimation springs tight and then collimate, this will have the effect of pulling the mirror further down the tube giving you a few extra mm's to work with.
Another more dramatic way is to replace the std focuser with the Guan Sheng (GSO) low profile Crayford with the 10:1 fine focus.
This will give you about another 20mm on in travel.
Just a thought.

Phil said...

Hi John,

Hmm. Another 20mm is potentially all I might need, as I got very close to focus with the 1.6X barlow. I have been eyeing some low-profile dual speed focusers actually, so we're on the same page!

Thanks for the hint about tilting the focuser. I messed with it this past afternoon and it was very easy and will make things much more comfortable. Nice!

I took my wife to Sydney last time we were in Melbourne (last year). Beautiful city really. We stayed in Circular Quay but ventured to the main harbour and walked throughout most of the city.


astronut said...

Well, you know the saying, Great minds think alike Lol!!
If you're ever in Sydney again, you'll have to pay us a visit!!
We have a great dark site in the Southern Highlands, s/w of Sydney.
Cheers, John.