How to see Galaxies

[shiladazz]

Hi All,

 

I have a 8 inch Dob and I use mostly a 8-24mm SVBony zoom EP and a Telrad. I am relatively new comer and just started to fill out my Messier checklist. I live in a mid size town and the 'Clear Outside' App tells me it is a Bortel 6. I can see mag 3 stars with naked eyes but not beyond. 

My tube is fairly collimated I suppose as I can see the stars as sharp points and can find the globular and open clusters. 

However, I have been trying for many days in vain to look at the galaxies. I follow the star atlas and 'Turn left at Orion' star hopping steps. But when I point at the spot where I am suppose to see the galaxy I see nothing. Not a smudge, no fuzzy glow, nothing. 

Obviously I am doing something wrong. Would you kind people tell me what are the obvious things to check as it is driving me crazy. 

 

Thank you 

[tuckstar]

I'm bortle 6 at home and struggle with the fainter galaxies in all but the best conditions. The sky isn't getting dark at present which won't help. You need to be dark adapted. Try for andromeda to star with. M81 and m82 are quite easy to find. You have enough aperture do see plenty. Sometimes its just knowing how to look, give it plenty of time at the eyepiece and learn about averted vision, looking but to one side and using the more sensitive part of your vision.

[Starwatcher2001]

This isn't the best time of year to go galaxy hunting as it only gets properly dark for a short period. I'm in a Bortel 7/8 and can see a few fuzzies, mostly in the winter.

Try to look for the ones closer to the zenith as you'll be looking through less atmosphere. Good dark adaption is a must (blanket over your head and eyepiece really helps. You might feel daft, but it really works).

Try gently tapping the eyepiece as the eye can often pick up movement better than static objects. Instead of looking directly at the object stare to one side and try to detect it in your peripheral vision. This is called "averted vision" and relies on the fact that the rods in your eye are better than the cones at night, but they are around the outer part of the retina rather than at the centre.

[Starwatcher2001]

Blimey just like buses, two very similar answers come along at the same time.

 

[Tomatobro]

agree with truckstar. Its just the wrong time of the year just need to give it a few weeks.

The eyepiece would not be my first choice I guess, with a 30mm giving you a better chance but if the zoom is all you have then stick with it. Greater magnification spreads the light out and makes things dimmer.

Double check that the telrad is calibrated properly ie aligned with the scope.

Once you see your first faint fuzzy and know how they look then it gets easier. You may have already looked at one but just not "seen" it

[AstroMuni]

If you own a pair of binoculars use them first. You can readily see Andromeda, M81,82 with a 50x10. Once you know where to look for them then you can aim for that spot using your scope.

But as others have pointed out, it may not be best season to go galaxy hunting.

If you have a camera try with that thro the telescope. An exposure of around 10secs should get you glorious shots. Good luck!

[Tiny Clanger]

I'll echo all of the above. I'm in a suburban area, with a 150 dob , and am keen on seeing the faint fuzzies , but have learned that quite apart from any limitations of my kit, there are many factors out of my control which affect my chances. I've managed a good few of the easier targets when the conditions  are right though, so here's what works best for me: I'd assume you are, like me,  in a light polluted area, as (I'm told ) such things are far easier to see from dark sites . But all my observing so far has been done during lockdown from my garden !

A  dark night . Not many of those right now, the best, darkest time in summer is an hour or so each side of 1am ( it would be midnight except for BST) Round here every other street light is turned off at midnight to save electricity, and by then the neighbours have stopped illuminating their conservatories like lighthouses too., so I aim to observe in the early hours.

No Moon in the sky. If the Moon is up, it or any bright planets are what I observe, not faint challenging DSOs  I also ensure any of my house lights which illuminate the garden even slightly, are off. A towel or similar, draped over head & eyepiece can help in a light polluted area.

A target fairly high in the sky. The lower you look, the more thickness of atmosphere you are peering through.

Fully light adapted eyes. I'll spend some time faffing with the 'scope, looking at the sky with the naked eye,  or observing  easy targets for half an hour, it takes at least that long for my eyes to properly adapt.

Averted vision: looking to the side of the target really works.

As for equipment, I've both a rigel quickfinder (with circles like the telrad) and a 9x50 optical  finder , and use those to star jump when I can. When that proves difficult, I've quite often used a combination of a £13 electronic level (little thing that runs off one AAA cell, and has a magnetic base , so sticks on my dob) and stellarium set to show me the current alt and az  of a target, With the little box showing me the alt angle with very good accuracy I just have to use it to set the tilt of the 'scope, then pan slowly across the correct area to hunt a object out.

For finding faint stuff I usually use a 32mm plossl or an 18mm BST starguider initially, only swapping to something with higher mag if and when I get to see my target. 18mm is the 'sweet spot' for my setup, local conditions and eyesight, apparently. It gives me the greatest contrast between sky and fuzzy thing.   Our eyes are better at spotting and recognising edges of shapes than gentle gradients of brightness, so you want to have as contrasty an image as possible to distinguish faint fuzzies from a fairly bright sky. There's plenty of info to read on here about exit pupil, which is an important factor in this.

Final thought : M31, Andromeda, sounds as if it ought to be an easy  target ,  right ? I thought so, I  mean, it's huge ! So I thought when I got my dob this time last year. I spent a few frustrating evenings not seeing it , despite being bloomin' sure I was pointing the 'scope straight at it .Then one warm summer night I went out with a camping mat, pillow and binoculars to just lie on the grass and watch for a meteor shower , the Perseids in August. About an hour after settling down I saw something out of the corner of my eye , a vague grey fuzz in the sky ... no ! It can't be ... but , it's in the right area ... Yep, after several evenings of annoyingly fruitless effort trying to see M31, I'd seen it entirely by accident with the naked eye.

Got it in the binoculars , then went in and fetched the dob (without turning any light on indoors so as to preserve my night vision) and managed to see a very underwhelming slightly brighter, thin cotton-wool ball, the bright centre of Andromeda. It looked better in the binos. to be honest. After that, I could see Andromeda with the naked eye on subsequent nights, no problem,  my brain knew what to expect.

It's one of the fascinating things about astro observing, quite apart from all the kit and technology, the correct aiming etc, you actually have to teach your eyes and mind what to look for.  It's frustrating to start with, but stick with it, persistence pays off eventually.

I'd suggest you have a shot at M81 & M82, Bode's  Galaxy and the Cigar  Galaxy, small , but high in the sky and easy to navigate to from the Plough, not to mention 2 for the price of 1 🙂

Heather

 

[Pixies]

Ditto the above.

M81 and M82 are probably the best targets to start with. M31 is probably still a little low. The latter is easy to find with binoculars, though, but just a faint smudge.

I'm also Bortle 6 using an 8" dob. When the skies are darker, you should be able to find quite a few galaxies, although they will be just faint fuzzies. Here's a quick list of some of the easier ones to observer (in my opinion), although not suitable all year round. 

• M81 and M82
• M31 - Andromeda
• M51 - Whirlpool
• M94, M106 - brighter ones in Canes Venatici
• M87 - Virgo A. Harder to locate, but quite bright (Spring)
• M49, M60 - other bright galaxies in Virgo (Spring)
• M64  - brighter ones  in Coma Berenices (Spring)

And on good nights, and mainly with averted vision:

• M65 and M66 in Leo Triple (best in Spring)
• M84 and M86 in Markarian's Chain (best in Spring)

Spring is definitely galaxy season!

Some of the above are harder to find, because they are in areas of the sky without many guide stars, especially a lot of the Virgo galaxies. A Telrad alone might not be enough and you will need either a wide-angle eyepiece, like a 32mm plossl, or an additional magnifying finder - an 8x50 RACI finder, for example. Practise is required. I enjoy using a zoom for galaxy hunting, as you can experiment to find the best magnification for each target that gives the best apparent contrast. However, the field-of-view of the zoom at 24mm is not very wide: I'd recommend a low powered fixed eyepiece to compliment it.

Start with M81 and M82. They should be easily visible with your equipment under Bortle 6 - once proper darkness returns. I am assuming you are in the northern hemisphere! Apologies if not.

 

 

[Cosmic Geoff]

the 'Clear Outside' App tells me it is a Bortel 6. I can see mag 3 stars with naked eyes but not beyond. 

Under these conditions, loooking for galaxies will be mostly a waste of time. You need to go to a dark skies area, or try some EEVA,  An ASI224MC camera attached to a 102mm f5 refractor on a GoTo mount has a usable field of view and works surprisingly well in unpromising conditions.  Spring is the best galaxy season in the northern hemisphere.

[Spile]

I would echo all the advice above. Patience, sitting down and averted vision help but dark skies top tump everything but once you have seen a few dark fuzzies, it does get a little easier to spot more but only if conditions are right. I find galaxy pairs easier to see so would recommend  Bodes/Cigar (M81/M82) in Ursa Major and M66/M65 in Leo. Short nights and DSO's do not make a good combination. As for finding them, I use a combination of asterisms, RACI and Stellarium screen shots - https://astro.catshill.com/finding-dim-objects/ 

[Zermelo]

I think the replies above have covered almost every angle on this, but from my own experiences so far I would pick out the following that I've found to be particularly relevant to me:

- finding the right magnification can be surprisingly beneficial in brighter skies. Your zoom EP will be ideal for exploring this. Start off with it set at 24mm and slowly increase the magnification - at a certain point you will notice the background sky starting to darken, which helps you to see fainter, less distinct targets.   It's sometimes a trade off between contrast and field of view - increasing the magnification will reduce the amount of sky you're seeing. Once you know how your scope and conditions respond, you can switch to fixed lenses if they are better quality. Some people are happy to do most of their observing with a zoom.
As mentioned by @Tiny Clanger, the exit pupil size is another way to think about this. It has been said that 2.4 mm is the ideal size for DSO hunting. You can calculate the pupil size for an eyepiece in your scope by dividing the focal length of the EP by the dob's F-ratio (you don't say what yours is, but it's usually about 5; it's the focal length divided by the aperture, in the same units).

- I've found that the combination of a good red dot finder (I have a Telrad) with a RACI optical finder is very effective for locating fainter objects. Both need to be aligned precisely with the main scope before each session. Use the red dot to position as well as you can, then check the star field in the optical finder against a map/app. Even when I can't see the target itself in the finder, I can position the scope with enough accuracy that I know for sure it will be in my eyepiece field of view. I have better skies than you, and I find a 6x30 finder adequate to show enough guide stars. With lighter skies you may need a finder with a larger aperture.

- observing experience makes a big difference to your success. My Messier checklist is now 80% complete, but I'm certain that there are quite a few that I've ticked off that I would never have noticed when I started out. As others have said, you need some easier "wins" to get your brain attuned to what you're looking for (yes, brain, not eyes). M81/82 perhaps, if you're in northern latitudes. If you're able to transport your dob, then the suggestion about a dark site is also a good one - not only will you be able to see more intrinsically, but you'll be able to experience a variety of faint objects that may help you recognize them back under lighter skies.

Yes, your location is certainly a hinderence for the faint fuzzies, but there are plenty of observers in this forum that perform miracles in even lighter skies.

[AstroMuni]

On 09/07/2021 at 17:28, Cosmic Geoff said:

An ASI224MC camera attached to a 102mm f5 refractor on a GoTo mount has a usable field of view and works surprisingly well in unpromising conditions. 

I'll second that on the ASI224mc being a user myself 🙂

[Broadymike]

I'm still very new to the stargazing game myself and at first was really struggling to find any DSOs at all. As others have said it's not the best time of year as we don't actually get astronomical darkness at the moment. I think it's actually over the next couple of days that we start to see it again. 

What I've found to be very handy is to use binoculars first (as long as the object is visible in bins). Once I've found it it helps me visualise where it is in relation to other stars. This means its so much easier to locate the object with the finder. 

Like others have said M31 and M81/82 are really good to start with as it's relatively easy star hopping to them. I use the andromeda constellation and cassiopea to find M31 and the handle of the plough for M81/82. 

I'm using a 4.5" newt at f8 and I'm in a bortle 5 area, so if I can find things your 8" dob should be easily as capable in your skies probably much better. The biggest thing is learning exactly what to expect to see. Completely forget about seeing DSOs in the same detail/colour that you see in pictures/magazines etc. They will mostly just be a faint grey fuzzy, especially at first. As your eyes adjust you'll tease out more detail but that is still limited. I actually realised when I finally found M81/82 for the first time that I'd probably already seen them in previous attempts but just didn't know what I should be looking for.  

The only other thing I'd possibly suggest that really helped me was getting a lower power EP. With a 1.25" focuser like I have 32mm is about the lowest power that 8s practical to use. If you have a 2" focuser you could go a bit lower. It gives you a much wider field of view meaning that you have a greater chance of getting your target in your EP. Obviously once you have it you can use a higher power EP if its needed.