Looking to expand

[Hooch]

Hi Guys,

Posted on here a while a ago when I bought my first scope. I am very impressed so far, makes you feel so small when looking at what is really our there!

I currently have a 'Celestron NexStar 130 SLT' http://www.celestron.com/astronomy/telescopes/celestron-nexstar-130slt.html. I have also made a few purchases to improve my viewing, these include a '1.25" 7mm 58 Degree TMB Planetary II'' eBay - The UK's Online Marketplace, a 2x Barlow lens eBay - The UK's Online Marketplace and 7 filters eBay - The UK's Online Marketplace. I am also getting a light pollution filter.

I am very happy so far with what I can see but I am looking for a lens that may allow me to see galaxy's. I take it I will need to go to a place that has very low light pollution? Any ideas?

Also any ideas on a case that I can store all my eye pieces and filters?

And.....Any eyepieces you guys recommend I will want? Currently I have the 2 eyepieces that came with the scope and the TMB Planetary II.

I was also looking to upgrade the scope as I don't really use the skyalign! Im not talking crazy money here!

[sgazer]

hi, galaxies come in lots of different sizes and brightnesses. The more magnification you use, the darker the image. Your scope is fairly small aperture, so I would stick with the brighter galaxies. Use Stellarium to see what's in the sky, check how bright they are and the size. Andromda galaxy is a good starting point, it's close, hence large at 3 degrees across and bright. So you need an eyepiece that will give you a 3 degree FOV. This can be worked out by dividing the FOV of the eyepiece by the magnification.

eg. if you have a 25mm eyepiece with 60degree FOV, you will have 650 (scope focal length)/25 (eyepiece focal length)=26x magnification and 60 (eyepiece FOV) /26 (magnification)=2.3 degrees actual FOV, which won't quite fit Andromeda. Maybe a 30mm eyepiece would be better (and brighter due to less magnification).

Other galaxies are much smaller so will need more magnification, but with a darker image you might not see much. Hence probably a 25-30mm eyepiece is best.

If you upgrade your scope, personally I would still recommend something that tracks what you are looking at. I never enjoyed my dob where the object disappeared every few seconds, but lots of people find them very easy to use. I also love goto, hence although I've sold most of my serious astro kit, I still have the SLT like you. I just stick a camera on it now or use the C80 for the moon planets and low mag stuff on galaxies etc.

If you've got a DSLR, try putting on the SLT with a normal lens.......the path to the dark side that is....LOL

[swamp thing]

Hi

The best advice for Galaxy observing is:

1/ find a dark sky site

2/ find a darker site

3/ find an even darker site

As you probably gathered a dark sky is THE most important thing involved in observing Galaxies.

No dark sky = no chance. Some brighter Galaxies can be viewed from urban skies but they're so washed out that the view is hardly pleasing.

Using your lowest power eyepiece to start with is always a good start.

Start searching for Galaxies with the highest surface brightness In the constellations nearest the zenith as these will be your best chance.

The Andromeda Galaxy is poorly placed at this time of year, better to start much higher in the sky, perhaps M81/82.

Regards Steve

[Hooch]

Ok, Cheers for that guys. Some interesting stuff to look into!!

What kind of eyepieces do you guys recommend then, whats your most used eyepieces and for seeing what?

I'm in a urban area which is annoying but once I get some decent kit I will start driving out to some darker patches.

[richbyers]

LOW power eyepieces are your friends here.....pushing it to see a galaxy wont help any, for my 130 i use a 25mm, and they fit nicely in, going any higer mag. just cuts out the brightness- which with my 130 i need all the help i can get

its actually surprising how big some dsos are- fore instance andromeda is huge in the eyepiece, and you certainly dont need a high mag for that

[Hooch]

Ok, well lower mag and darker sky for galaxy.

Any advice of eyepieces then?

Or even scopes, I do like the look of the skyliner dobs but I would have nowhere to store it. Any reflectors that stand out as being really good? I did see a tal-1 the other day for sale at £30 but it had sold very quickly!!

[Hooch]

Oh and I have been using the Google Sky Map app on my phone which is in all honesty amazing!

[swamp thing]

Which eyepiece you use will depend a lot on your scope.

What you are looking for is an eyepiece which gives you an exit pupil 4-5mm. This will be pretty good for Galaxy observing from most sites.

To find exit pupil divide the aperture of the scope by the magnification being used.

If you use really dark sites to observe you can push for larger exit pupils and lower mags. But from any LP areas I wouldn't go much higher than 5mm.

As for scopes. Well the best scopes for Galaxies are the ones under dark skies, so whichever one you can manage to get to a dark sly will be best. Get the largest aperture you can manage NOTHING else is important for Galaxies. Dobs rule for this sort of observing because all of your money is paying for optics.

But don't lose sight of the fact that dark skies are the most important factor. NEVER substitute the ability to transport a scope to them for aperture. You'll see more through a 6" under a dark sky than a 16" from a city centre.

Regards Steve