10" Truss Dobsonian for Deep Sky Objects

[Shonjon (Eric)]

I am 15 years old and I have been excited to get my Meade Lightbridge 10" Dobsonian for ages, and now i have it. I've been studying things in the sky right now, Omega Centauri, M8, Saturn, all the viewa were pretty spectacular. The thing I was looking forward to viewing th most was M104, the Sombrero Galaxy. Especially from these pictures on this webpage http://www.sydneyobservatory.com.au/...n-the-suburbs/

The sketch through the 10" got me excited. I starhopped all the way to M104, only to find a faint wisp of smoke. My telescope is collimated to the accuracy a laser collimator can go to, Why would my image be so faint. Many other nebula that I have tried to witness that are said to be spectacular in 8 inches, I can't seem to locate at all.

I really want to see these galaxies and nebula which I've been told should show up easily in a telescope with a 10" apeture.

Quick specs on my 'scope
Focal Length: 1270mm
Appeture: 254mm
Focal Ratio: f/5
Eyepiece Focal Length: 26mm and a 9mm

Thank you very much.

[barx1963 (Malcolm)]

Hi Eric. Welcome to IIS and congratulations on the new scope.
Galaxies are very often hard to see, they have a low surface brightness and are quite extended and so are badly affexted by conditions and light pollution. M104 is one of the nicer ones to view but it still needs good conditions to see it well. It is now starting to sink low in the west which makes it harder to observe also.
Persevere with it, go back to it each time you take the scope out and you will hopefully get a good night and your own eye will pick up more detail.
Malcolm

[michaellxv (Michael)]

Eric.

I have the same scope and there is plenty you will be able to see with it. As Malcolm says persevere as it takes a bit of practice but well worth the effort.

This time of year there is plenty to see around Scorpius which is high in the west after sunset.

Michael.

[ZeroID (Brent)]

Malcolm has it right Eric, galaxies are hard to see especially from LP areas. I can only just make out Sombrero in my 10" on a good night. Those pix you see posted with stunning viiews are the summation of often hours of exposure with sensitive cameras and much manipulation in Photoshop like applications.
Another one you might find worth looking at is Sculptor, NGC 253. I have been able to see that a bit clearer, enough to define shape and luminance. Bit hard to find as there are not many marker stars in the region but it is a good hunting exercise.
Obviously a dark site will give better views but they will always be faint little smudges in the skies.

[Paddy (Patrick)]

Alas Eric as others have said, galaxies can be very faint. As Malcolm points out, keep going back and you will see more. Also it pays to understand the physiology of the eye. When you view something faint, the photoreceptor cells on your retina that you need to use are the very sensitive night vision rod cells, not the day vision cone cells. The fovea, which is the part of your retina that you use when you look directly at something has no rod cells at all, so if you look straight at many deep sky objects, you won't see much at all. Get it in the middle of your eyepiece and look to a bit one side of the galaxy and you will be amazed how much more you will see. The temptation is to look straight at it, but this will get rid of just about everything. The other thing to bear in mind is that the rod cells do not encode colour like the cone cells do. So most DSOs will appear in shades of grey, but still very beautiful as you learn to tease out the detail.

Collimation may make a bit of a difference. I used to use a laser only, but when I invested in a cheshire eyepiece as well, I found I could place the secondary with much greater accuracy. But the main issue will be the low surface brightness - averted vision and repeated observation will help. And also the end of La Nina. This year has been the pits for galaxies down here as there is so much moisture in the air. With dark skies and a 16" scope, M104 is usually stunning from my backyard, but it's been quite ordinary all year. I really haven't bothered with galaxy obs much at all. Even bright ones just look like they're in a sea of muck.