Easiest Southern galaxy to observe spiral structure?

JoeBlow · #1 10-04-2016, 04:07 PM

Hi all,

In your experience what is the easiest galaxy to observe spiral detail that is well positioned for observers in southern latitudes? I'm especially interested in ones that will show in medium sized telescopes (8" to 10") from dark skies.

There is a lot of info about ones far North but no so much for us southerners, especially when it comes to personl experiences.

On at least one occasion I saw some very strong hints of spiral structure on m83 in my 8". If circumstances had been just a little more ideal at the time I believed I could have clearly seen them.

Can anyone suggest any better candidates than m83?

Thanks,

Joe

Paddy (Patrick) · #2 10-04-2016, 06:55 PM

M83 is my pick for this time of year. NGC 1566 is a ripper in Dorado and would be viewable at the moment. Not sure how it would go in 8-10" scopes. NGC 1365 is also one of the standouts, but would be keeping unsociable hours at present.

Oh, there is also the Large Magellanic Cloud, a barred spiral, a bit bent, but good for binos especially to pick up the north spiral arm.

JoeBlow · #3 10-04-2016, 11:23 PM

Quote:

Originally Posted by Paddy

NGC 1566 is a ripper in Dorado and would be viewable at the moment. Not sure how it would go in 8-10" scopes.

What a coincidence! I just came back inside after an observing session that included NGC 1566. At 167x and averted vision I think I might have seen hints of spiral arms, but nothing concrete. This was from my home in the suburbs, which is actually quite alright for a suburban location. I have to try this one again from my dark sky site.

I only wish we had something more like M51 here...

Atmos (Colin) · #4 10-04-2016, 11:49 PM

I would also put NGC 4038 on there. A few months ago I spotted it with my 5.1" refractor at maybe 140x. Saw it against two nights ago through an 18.5" and it was far more clearly visible.

ausastronomer (John Bambury) · #5 12-04-2016, 04:33 PM

NGC 2997 in Antlia is a good face on spiral that is near the zenith around 11pm at present.

It is one of my favourite galaxies in my 18" scope, under dark skies you will get good detail in a 10" scope.

Cheers,
John B

ausastronomer (John Bambury) · #6 12-04-2016, 05:07 PM

Another good one for A 10" scope is NGC 2442 (The Meathook) in Volans. This is a barred spiral. In a 10" scope with averted vision you should see the central bar and the "hooks" at both ends.

Cheers,
John B

janoskiss (Steve H) · #7 12-04-2016, 06:59 PM

Great question. On NGC 1365 it is very easy to see the two prominent arms.

I don't believe I have seen either of the ones John B recommended but I will now have to go out and look for them because they do look like interesting targets.

If you take your time going for a visual stroll around nearby galaxy clusters (e.g., Virgo, Fornax) under dark skies, you will find galaxies of all kinds. The "boring" elliptical ones are the most common and easiest to pick up visually, but there are plenty of spirals and other shapes. Gravitationally bound tight groupings and ones in the process of collision are always fun too.

You can see a fair bit of detail with an 8" if you take your time and conditions are good. Averted vision is your friend. Takes a bit of getting used to but it's rewarding.

Bombardon (Eugene) · #8 13-04-2016, 11:56 AM

Hope the huge Silver Coin, NGC 253 can join the list- even out of season -as my first view of this mag 7 spiral in a newly minted 8" was staggering.
The nearby M55 is also impressive. Regards, Eugene

niko · #9 13-04-2016, 01:09 PM

Southern pinwheel?

JoeBlow · #10 15-04-2016, 10:05 PM

Thanks everyone! Thats a nice selection for me to to try out in my 8" once I get back to my dark site.

janoskiss (Steve H) · #11 16-04-2016, 03:54 PM

Quote:

Originally Posted by niko

Southern pinwheel?

IIRC that's M83

JoeBlow · #12 08-05-2016, 09:26 PM

Friday night I finally saw two spiral arms in M83 from my dark site, though I couldn't see the arms extend all the way around. They gave M83 a barred galaxy appearance.

However the highlight of the night was seeing M51 for the first time. At my site I have a clear northern horizon, so I waited for M51 to poke it's head above the horizon and caught it before it started to make it's way back down. Despite being only a few degrees above the horizon, both it and NGC 5195 were so bright! Their mottled appearance was very clearly visible. I can only imagine how good it would look if it passed overhead.

speach (Simon) · #13 09-05-2016, 08:43 AM

m83 it's observable in a 6"

JoeBlow · #14 09-05-2016, 10:31 AM

M83 is detectable in even quiet small telescopes. However seeing spiral structure is a challenge in almost any amateur telescope from a suburban location.

Tinderboxsky (Steve) · #15 09-05-2016, 11:31 AM

Quote:

Originally Posted by JoeBlow

M83 is detectable in even quiet small telescopes. However seeing spiral structure is a challenge in almost any amateur telescope from a suburban location.

Dark skies certainly make a big difference. M83 is a relatively straightforward target from my dark skies on the coast south of Hobart with my 140mm refractor.
To quote my notes from my last observation in 2015: "broad very faint diffuse glow with some brightening towards the centre and a brighter central diffuse spot. Occasional better seeing gave a glimpse of a spiral structure to the faint glow." Scope: Vixen NA140 with Baadar binoviewer at 68X.

Steve

ngcles · #16 09-05-2016, 10:50 PM

Hi All,

My money is on M83. I have seen spiral structure in M83 using a 15cm f/6 Newtonian from a true dark site.

Best,

L.

dreamstation (James) · #17 10-05-2016, 03:56 PM

I've tried observing M83 in my 10" a number of times but apart from seeing a large faint glow and a slightly brighter faint glow in the center which I assume is the core, we couldn't see any detail whatsoever. I always thought we lived in a reasonably dark area but comparing our results to other people's observations, we mustn't.

Tinderboxsky (Steve) · #18 10-05-2016, 05:37 PM

Quote:

Originally Posted by dreamstation

I've tried observing M83 in my 10" a number of times but apart from seeing a large faint glow and a slightly brighter faint glow in the center which I assume is the core, we couldn't see any detail whatsoever. I always thought we lived in a reasonably dark area but comparing our results to other people's observations, we mustn't.

James, less than ideal seeing conditions and transparency might be the culprit given you are on the coast. Is your scope well collimated?

Steve.

dreamstation (James) · #19 12-05-2016, 03:03 PM

Quote:

Originally Posted by Tinderboxsky

James, less than ideal seeing conditions and transparency might be the culprit given you are on the coast. Is your scope well collimated?

Steve.

Steve, I believe our scopes are collimated decent enough though I don't use any lasers or gadgetry to help do so. It may not be perfect as a result but it looks 'near enough' to my eyes. I regularly do the out of focus star trick to see how even the ring looks. Is this an adequate test to do quickly or should I be more thorough in my setup?

ausastronomer (John Bambury) · #20 12-05-2016, 05:29 PM

Quote:

Originally Posted by dreamstation

Steve, I believe our scopes are collimated decent enough though I don't use any lasers or gadgetry to help do so. It may not be perfect as a result but it looks 'near enough' to my eyes. I regularly do the out of focus star trick to see how even the ring looks. Is this an adequate test to do quickly or should I be more thorough in my setup?

Hi James,

When you check your collimation on a star you need to check it both inside and outside focus. You defocus by the same amount on either side of focus. You should get nice concentric perfectly circular rings both sides of focus and the secondary shadow should be perfectly centered in those rings and round. If your secondary collimation and or positioning is out you will get a different image inside of focus to outside of focus. The outside focus image could be perfect but the inside focus image may not be indicating the telescope is not properly collimated.

In regards to M83. This is easily the brightest face on spiral galaxy visible in the southern hemisphere (apart from the Large Magellanic Cloud). Under "dark" pristine skies you should see spiral structure in a 10" telescope. However, you need to understand the difference between "dark" and "sort of dark". Many new astronomers, or non astronomers think its dark as soon as they are 20km away from a city. That isn't the case. What does the light pollution map show your area as? If you want to give me your latitude and longitude co ordinates of your observing site I can check it for you.

Cheers,
John B