nebulae - what can I see with an 8 inch dob?

[coffee_prince]

What nebulae can I actually see through an 8 inch dob?

I have very bad light pollution. The problem with stellarium is that it odesn't tell me what can be seen, or what nebulae are far too dim for an 8 inch to see

I have a southern facing garden so I am limited in my view

Thanks

[brantuk]

Southern facing is good cos you get the ecliptic across the whole view. M42 will be very clear and visible in an 8" dob and you'll see the Swan, Andromeda, M13, any number of doubles plus all sorts of stuff no problem. Don't expect glossy colours though - it'll mostly be shades of grey and black and white.

You'll see colours on planets like jupiter and mars and double stars like alberio will give off a beautiful blue and gold

Also - have a play with this site - it shows roughly what you can see either in a camera or observing at the eyepeice:

http://www.12dstring.me.uk/fov.htm

[RikM]

You should be able to see a few nebulae with an 8". M27, M57, M97 and M42/43 should be a doddle. If you push the magnification you should be able to find M1 and the Eskimo nebula as well. Be aware that they are all rather dim grey smudges even under the best conditions so don't expect Hubble images.

In the 'sky and viewing options' window in Stellarium, you can tweak the LP level to match your sky. Just pick a constellation and count which stars you can see, then adjust the level to match. The default setting is 3, my sky varies from 5 to 7. It is a pretty good match for what I can see.

[coffee_prince]

I looked at andromeda on stellarium but it appears very low on the horizon at around 4am so I am not sure how late I could stay up or if it will be in view.

I've seen a few faint fuzzies before so know what to expect, I just like the idea of hunting them out, I find planets less interesting!

Thanks for the suggestions guys, will look up before I go out to the garden tonight, quite excited as clear weather in the weekend in a long time

[RikM]

If you are out tonight you will probably struggle as the moon will wash out a lot of faint stuff. M57 'the ring nebula' is probably the best placed at the moment. Nice and easy to find mid way between the lower pair of main stars in Lyra. You will probably be better off hunting down a few globular clusters: M13, M3, M5, M92.

[coffee_prince]

thanks for the tips, yes the sky is not very dark at all at the moment

[brantuk]

Yes - you'll have to wait for andromeda to come round in the autumn - I was really just answering what you'll be able to see in an 8" dob without referencing what's up at the moment. Right now we're in globular season

[Adz]

Southern facing is good cos you get the ecliptic across the whole view. M42 will be very clear and visible in an 8" dob and you'll see the Swan, Andromeda, M13, any number of doubles plus all sorts of stuff no problem. Don't expect glossy colours though - it'll mostly be shades of grey and black and white.

You'll see colours on planets like jupiter and mars and double stars like alberio will give off a beautiful blue and gold

Also - have a play with this site - it shows roughly what you can see either in a camera or observing at the eyepeice:

http://www.12dstring.me.uk/fov.htm

Thanks for that really helpful link Kim. Is it fully working though? I just compared the view of a 13mm nagler to a 13mm ethos and the magnification changed...?

[banner001]

and for nebulae you really should get a filter, a UHC or OIII is a must.

[twotter]

Stellarium has a feature where you can effectively add in your local light pollution, by removing the fainter magnitude objects. Using that & the ocular plugin should give a reasonable indication of what you can expect to see with an 8 inch dob

[Cosmin]

and for nebulae you really should get a filter, a UHC or OIII is a must.

Do these filters enhance the contrast significantly? Would you recommend a filter to use with my Nexstar 6SE? Only once did I have the opportunity to view an object (M27) with and without the filter for comparison at a star party and I really couldn't tell the difference. I don't know if it was UHC or OIII though.

[NickK]

M42 should be a doddle - you can see this with the naked eye and it's a great training DSO that is easy to locate too. It's got everything - stars, nebulosity that get better as your dark adaption gets better and companions around it.

If you can find Orion's Belt, you can find M42.

Next I'd suggest star hopping to Pleiades

More advanced is possibly M51. Which will take a little longer to find and identify. (if it's available)

If you have a lot of LP I would recommend the Baader Neodymium Light Pollution filter. It will help open up more objects to observing (although it does slightly darken them).

[the_laughing_crow]

astronomy.com provide a weekly podcast with targets to hunt down that week with a few targets for smaller scopes and a few targets for larger scopes. Im sure that'll keep you amused

Podcasts - Astronomy Magazine

[brantuk]

@Adam - d-string is good for a very general idea - make sure you pick the obs view (not the camera view). Alternatively - and a bit more accurate is CCDCalc from New Astronomy (free download):

The New CCD Astronomy Home Page

There are loads of these around - some may be better than the two I suggest - but I only use them as a rough obs guide)

[RikM]

@Adam - d-string is good for a very general idea - make sure you pick the obs view (not the camera view). Alternatively - and a bit more accurate is CCDCalc from New Astronomy (free download):

The New CCD Astronomy Home Page

There are loads of these around - some may be better than the two I suggest - but I only use them as a rough obs guide)

I find that these EP calculator sites are fine for showing you how big an object will appear in the eyepiece, but they still use 'Hubble' images. They don't in any way show you what the object will actually look like, i.e. a grey smudge most of the time.

[superjody]

Southern facing is good cos you get the ecliptic across the whole view. M42 will be very clear and visible in an 8" dob and you'll see the Swan, Andromeda, M13, any number of doubles plus all sorts of stuff no problem. Don't expect glossy colours though - it'll mostly be shades of grey and black and white.

You'll see colours on planets like jupiter and mars and double stars like alberio will give off a beautiful blue and gold

Also - have a play with this site - it shows roughly what you can see either in a camera or observing at the eyepeice:

http://www.12dstring.me.uk/fov.htm

Just had a look on this site and its great, shows you everything as you would see it, thanks for posting

[brantuk]

@Rik - yes I agree - sizing is really my main use - so I can pick an appropriate size ep

@SuperJody - you're welcome

[banner001]

Do these filters enhance the contrast significantly? Would you recommend a filter to use with my Nexstar 6SE? Only once did I have the opportunity to view an object (M27) with and without the filter for comparison at a star party and I really couldn't tell the difference. I don't know if it was UHC or OIII though.

its quite a difference in contrast, for even more contrast (usually) you can use the OIII filter.

UHC allows H-beta and oxygen emission light through, the OIII only lets in the oxygen emission light in.

you probably looked through a light pollution filter, nebula filters are very different and are only used for nebula's, they dim everything else too much.

at dark sky sites if you hold up the nebula filter to your eye you can almost see the nebula with no scope...almost for your telescope either would be suitable, but i would stick with tradition and go for the UHC.

[coffee_prince]

Bump, had a little nosey tonight and I couldn't find any faint fuzzies (e.g. andromeda).. Is this because the moon is out?

The main thing I found tnight was a double cluster

To get an idea of light pollution, I need to put stellarium light pollution onto level 9. There are not too many stars visible with the naked eye right now

[umadog]

With that much light pollution you will have a very hard time seeing any but the very brightest galaxies. Galaxies suffer the most from light pollution and aren't aided by filters. You will have the most luck with planetary nebulae, which have high surface brightness. Check out M27, M57, the blinking planetary, the blue snowball, amongst many others. The brighter diffuse nebulae will also be easy targets. For instance, M42 and M8. Maybe you could try working through the Urban List: http://www.astroleague.org/al/obsclubs/urban/urban.html

You might be interested in the software tool "SkyTools" which seeks to predict which objects will be visible under user-defined sky conditions.

As others have mentioned, a light pollution filter will help. However, you need to be well dark adapted to get the most from these.

The best thing you could possibly do, however, is get out to some darker skies. Your 8" in dark skies will blow the pants off a 25" in suburbia. Seriously.

From home you could try embracing double stars. There are some really cool ones, as it happens.

[coffee_prince]

Another disheartening evening, spent 90 minutes trying to find any faint fuzzies, could not see anything. e.g. tried the ring nebula, its not far from lyra.

I don't know what is the problem, as I had no problem locating actual stars, is this a case of something wrong with my telescope, or light pollution, or that it isn't dark enough where I am?

I remember last winter it was so dark I couldn't see where I was going, but right now its not dark enough so I can see the floor etc, and there are a lot of bedroom lights on etc

Anyway, kinda depressing :s IWith so little results I find it hard to justify spending more money atm, I wanted a telrad and new EPs

[garethmob]

i found the ring neb is one of them ones that u cant look at directly, you have to use whats called averted vision (basacally looking at one of the corners of the eyepeice) also the longer u look the more you see, theres a star in the middle of it, and then u start seein the faint fuzzyness around it tapping the tube can help, it adds vibrations which as the scope moves it can show the fuzzyness!!

andromedia i found was a little big in my 25mm a 32mm shows it quite well u can make out the gray "dustlanes"

as the guys av said a LP filter is a must!

iv got the baader neodymium filter, its also very useful on planets and the moon (on my little 102st it actually cuts the fringing colour but u wont be effected on ur 8")

First Light Optics - Baader Neodymium Filter

[umadog]

Ok, coffee... I remember when I was starting out I often wondered if there was "something wrong with the scope." Generally this is not the case. If you're seeing reasonably sharp star images than chances are that everything is just fine. Even if you're quite far out of collimation, all that will do is make things a little blurry or asymmetrical. It won't actually stop you from seeing gross features in the sky. Don't worry about your scope. As you learn more this worry will fade.

Next, the ring nebula. I think there are two problems. Firstly, you may not be pointing the scope in the right place. A Telrad will really help you find stuff. It's well worth spending the money on it. Secondly, you may not know what to look for even if the object is in the field. The ring nebula is pretty small: at low powers it will look like a bloated star at first glance. Don't expect a great big ring. At higher powers you will discern a ring. The nebula is fairly bright. With averted vision you will see extra details but it stands up to direct vision pretty well.

Just so you know: the central star in the ring is a notoriously difficult target. Don't be disappointed if you don't see it! Even in magnitude 7 skies, it might be be right at the limit of what an 8" Dob can show. It's really a 10" and up object, although many observers feel it needs yet larger scopes. Furthermore, what the star really needs is very good seeing since you need to use powers in the region of 400x. It's embedded in the nebulosity of the ring so the contrast between the star and the background is poor. Here's a page on it: Telescope Reviews: Central Star in M57 The central star in the Dumbbell Nebula is substantially easier.

[banner001]

Bump, had a little nosey tonight and I couldn't find any faint fuzzies (e.g. andromeda).. Is this because the moon is out?

The main thing I found tnight was a double cluster

To get an idea of light pollution, I need to put stellarium light pollution onto level 9. There are not too many stars visible with the naked eye right now

where in the world are you?

even in my back garden whick is almost completely black andromeda is hard to see even at low mag, 60x is still big for andromeda...i can see it better in the finderscope almost!

i have a 10" scope so im not collecting that much more light than you (~40% more), what magnifications are you trying to view at? i find 60x - 100x plenty for most things, anything more and the UK weather is so bad that everything just becomes blury, better to be small and sharp IMO.

and to echo what the others have said, if you have access to a car, get yourself out to a dark site, or even get to 10 miles from big cities, the difference is quite noticible. in light polluted coventry (8 on stellarium) my 10" shows me the same as the 4.5" i had out in the rural area 10 miles south of huddersfield (6-7 on stellarium) for faint objects.

[coffee_prince]

thats why I am a little worried something is wrong :s

I know it isn't dark here atm, i don't need torches or anything because theres so much artifical lights going on in my back garden, and the neighbours dont use curtains for some reason? i know it used to be darker, to the point where i can't see where i am going. this was when i could see pleiades with the naked eye, but i think that is quite bright anyway.

i have read mixed reviews about filters, i have read more often than not on here that for visual use they are questionable, so i am going to hold back on buying it as i only have so much money available to spend.

I was exclusively using my 25mm which gives me 48x

I can see a lot of stars, but sadly nothing else

p.s tried the star test and there is a lot of air turbulence, maybe its becausethere are so many airplanes flying directly above me, would this affect seeing?