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Is there a way to quickly identify/find DSOs

Arcturian

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Arcturian

Arcturian

Posted
Posted

The area I live in isn't great light-pollution wise, but I do my observing late at night, how can I find DSOs, like nebulae and gas shrouded stars like pleiades? I've tried to find m31 (andromeda) before but had no luck. What I'm really saying is, what's a good method to find objects other than lone stars? and what sort of magnification is needed? My standard lens should be 90x, It's a 10mm wide-field lens, with 900mm focal length, divide focal length by lens diameter.. 90x.

Also what's the difference between my standard 10mm lens and my wide-field 10mm,

I recently bought;
"4 Piece standard telescope eye piece lens set. 4mm, 6mm, 12mm, 20mm eyepieces as a whole set.".. So will soon have a larger range of magnifications available :smiley:

-Arc

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Qualia

Qualia

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Here is some general advice you may find useful for hunting out DSOs:

Gear & Stuff

i) Stellarium: download this free software. It is extremely useful for planning sessions, seeing what is about, learning about constellation and planetary motion through time and much more.

iI) Star Atlas: get yourself a decent star map. I find Star Atlas by Sky and Telescope indispensable. It's not that expensive, it's a piece of art in itself and it is extremely useful.

iiI) Viewfinder: a 9x50mm, right angled correct image viewfinder is the business. This delivers stars right down to about 8 magnitude, even if you're in a LP area, meaning you’ll be able to see every star plotted on the Sky Atlas and when you move amongst those stars, your left is left and your up is up.

iv) Red-Dot Finder: either a Telrad or Rigel finder will be a big help. These can’t deliver more stars than your eyes alone can see, so if you're in an LP area, you're relatively limited. But, they really do speed up your finding, really do help judge where you are, but it must be used in conjunction with the findercope. Whether in decent dark skies or a light soaked LP area, one positions the bullseye or the other two rings in the proper place against the stars and you’re done. If you're out a little you can work out where you are by either looking through your viewfinder or the three ringed cirlces of the red-dot finder giving you varying degrees of the sky you're looking at. If it helps, you can make a plastic red-dot finder overlay for the Star Atlas or just print one of the free Telrad maps on the net.

v) Long Focal Length EP: A long focal length, low magnification EP will be your identifying workhorse. The low mag EP should offer you sufficient sky to manage along with your star map and red-dot finder and ought to be able to pick out or hint at what you're hunting. I use an EP which offers about 1º true field around 50x, others may prefer a little wider.

vi) Sketches: sketches are too often overlooked, but they ought to be viewed from time to time. These are generally produced by patient observers who are trying to get the visual image right, so the little drawings should give you a very good idea of what the DSO being hunted out will more or less look like.

vi) SGL & Books: there are so many books about it's hard to pick out any one of them and say, this is the best. There are those which give context and depth to what is being viewed, others a more practical working guide. On the latter front, many folk recommend, Turn Left at Orion. I never really bothered but others swear by it. The power of SGL goes without saying.

vii) Jumping Tricks: there are some little tricks you can learn to find yourself about the night sky. For example, find the plough in Ursa Major and look for Merek and Dubhe, the distance and angle between these two is one step. Now count that distance, in that direction another 5 steps and bingo, you'll be with Polaris. Now go back to the Plough and find its end star, Alkaid. Take a jump and dive from her and the next brightest star will be Arcturus, and so on. Learning the big stars and diving quickly between them makes hunting stuff easier.

viii) Participation in the Virtues: if you can master patience you'll be a master of yourself and the night sky is a good teacher. She'll teach patience and careful watchfulness; she'll teach industry and care and above all the night sky teaches trust. Those stars and DSOs are not going anywhere quick. They won't desert you and they're not trying to deceive you. If you don't succeed one night, no worries. Don't be down hearted, you've probably already discovered something new about yourself, or perhaps your equipment, or the sky itself. And those stars and DSOs will be back to give you another chance, another day.

ix) Don't fight the clouds: stargazing can be a tiresome road and one can suffer for it and be grieved, but the worst we can do is add to this frustration and hit out and curse those things beyond our control. Cloudy, uneventful evenings are just that, nothing more and when we are older they will appear to us as a singular, non-descript event, yet shining from them like a host of gleaming stars will be those evenings where everything just seemed perfect and the universe at last could murmur to us its secrets.

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ronin

ronin

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If you were trying to see Andromeda in the last few nights then close to no chance, the moon will have been too bright, add in the light pollution you likely suffer then that really drops the chances.

I still say try binoculars not a scope for Andromeda as well.

You do really have to know the stars or at least the constellations, that is simply how DSO's are located.

Like M109 is right next to Phecda in the Plough, the star is easy to find and so "should" M109 be but there is no other way of stating it's position in simple terms. Even M42 (Orion Nebula) is described as below the belt of Orion, so you still have to know Orion and locate the belt stars. Easy but still described by constellation and stars.

For Andromeda the best is to wait for 10 days, not this weekend but to following then try. The moon will be smalland so the skys likely dark enough. Assuming there is an absence of clouds.

Go search through a few astronomy guides to the constellations and find one that you can follow - not all books are equal to all people. Then simply spend some time working out which is which. After that comes comes using the stars in them to find other less obvious objects.

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acey

acey

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OP location is London, so the greatest difficulty in observing DSOs will be light pollution - very few will be visible. Even the core of M31 may be very difficult. The Pleiades are an easy target, but the reflection nebulosity around the stars is extremely difficult, even at a dark site, and certainly impossible at a light polluted one (filters can't help). Best DSOs to try would be star clusters - e.g. Pleiades, NGC 457, etc. The Moon (even a full one) makes relatively little difference to the already bright London sky, but things might get just a little better once it's out of the way. The Orion Nebula M42 (currently a late-night object but rising earlier as winter comes) will be worth trying. The Ring Nebula M57 might be visible - a nebula filter would help in that case (also covering the head to screen out stray light). But the most rewarding targets will probably be the Moon and planets.

OP also asks the difference between standard and wide-field 10mm EPs. The difference is that the latter shows more sky at the same magnification. That matters if you care about getting the whole of a large DSO in a single view. Personally I don't but it's a matter of taste. I do find wide-field eyepieces useful when using an undriven scope (dobsonian) at high power, because it's easier to track.

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jetstream

jetstream

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A fun and helpful thing is to practise identifying constellations, knowing these will lead you very close to a lot of DSO. Most constellations show up well from LP skies. M13 for example, find the Hercules "keystone" , check out the map and the cluster is yours. M31 can be hard actually, I use 4 fingers width above Mirach ( 2 deg/ finger) and point the scope there. Or line up Mirach (mag 2) and Mu Andromedae ( mag 3.8) and its just over 1 finger width above.

Use a low power EP with as wide of field as you have. I can see it in my 90mm from LP mag 18 skies.

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ghostdance

ghostdance

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OP location is London, so the greatest difficulty in observing DSOs will be light pollution - very few will be visible. Even the core of M31 may be very difficult. The Pleiades are an easy target, but the reflection nebulosity around the stars is extremely difficult, even at a dark site, and certainly impossible at a light polluted one (filters can't help). Best DSOs to try would be star clusters - e.g. Pleiades, NGC 457, etc. The Moon (even a full one) makes relatively little difference to the already bright London sky, but things might get just a little better once it's out of the way. The Orion Nebula M42 (currently a late-night object but rising earlier as winter comes) will be worth trying. The Ring Nebula M57 might be visible - a nebula filter would help in that case (also covering the head to screen out stray light). But the most rewarding targets will probably be the Moon and planets.

Agreed acey, you're almost absolutely right, of course, but this is no counsel of despair ( I know that's not at all what you intended nor am I intending a stickpoke at your post, just wanted to give my experience). With my 6" F5 in pretty shot skies, being right next to the glowbowls that are Stratford (& not on Avon!) and Hackney, I can find & see the Ring (averted vision comes in dead handy as does a UHC filter), core of Andromeda (on really clear nights a hint of it's wider structure - still practising this & hope to see more as I improve my observing skills), and lately the Dumbbell* so while I absolutely agree that our good ol' London skies are nowhere near dark, & certainly inhibit good seeing etc don't be disheartened Arc....Some of the more obvious DSO's are very possible! Difficult sometimes, yes; not as good as from dark sites, certainly...but keep tryin' - they're up there.

And wait til you get to the clusters...drop-dead gorgeous! Even from the orangery...

Nil desperandum  - took me ages to track down some of the more obvious targets (cough, M31 & M13) that everyone else was finding like shooting fish in a bucket. But I finally found em, thanks in large part to posts like Qualia's above and other great assistance from the hoary beards (& beardesses) of SGL. 

Excelsior to you all!

*I even found this with the Moon just swinging it's multi-armed lightsaber into view....not much detail but hey, a palpable hit nonetheless :)

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