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M13, M27 and M31 (?)


GavStar
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Since it was a clear and warm night I decided to try to find some of the objects in TLAO. The best summer objects were given as M13 and M27, and I found these quite easily with my TV85. Although they both looked very smudge like, they looked like TLAO indicated and I was very pleased with the views. I tried a range of eyepieces including 22mm, 14mm, 8mm and 4.5mm. My preference was 14mm, about 50x magnification. I then decided to try for the big galaxy, M31. I live in SW London and was observing in my back garden so the light pollution is I'm sure very bad. However, even so, M31 looked very similar to M13, ie a fairly circular smudge, I couldn't really see any oval shape. Is it possible that I saw something else? I was certainly in the broad area of M31 and had a good sweep of the area around it, but couldn't see any other smudges. I was surprised that it didn't look much bigger than M13....

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that's pretty much how it looks uner a light polluted sky. If you have a large enough scope and darker skies you will get a better view but with a small scope or under bright skies you only see the central core, lanes and shape need apparture and darker skies

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Here are some examples of the kind of thing a 4" frac, viewed from an inner city roof top, looks upon:

M 27

post-21324-0-49775800-1378172654_thumb.p

M 3

post-21324-0-77267200-1378175502_thumb.p

M 57

post-21324-0-01586600-1378175802_thumb.p

M94

post-21324-0-05029400-1378175743_thumb.p

M15

post-21324-0-96143600-1378175919_thumb.p

And here is what the 4" does under the same conditions with clusters and double stars:

Double Cluster

post-21324-0-25749900-1378176009_thumb.p

NGC 752

post-21324-0-07567700-1378176048_thumb.p

Gamma Andromedae

post-21324-0-23903800-1378176129_thumb.p

Eta Persei

post-21324-0-88834500-1378176225_thumb.p

Here's what to expect from Jupiter and the Moon:

Moon

post-21324-0-53109100-1378176358_thumb.j

Jupiter

post-21324-0-61444700-1378176513_thumb.p

I guess this is the kind of view you'll be getting as well.

In general, try to view an object as close to the zenith as possible and bear in mind that as a general rule of thumb the brightness of an object will decline as you up the magnification. If I up the mag twofold, say, I'm reducing the image brightness by a factor of four. If I keep on doing this eventually details just disappear. On the other hand, increasing the mag does make detail more apparent, so, as you can appreciate, we're now at a trade-off: will increasing magnification gain more detail even though I'm making the object fainter?

You've got a wonderful telescope, Gavster but we cannot break the laws of physics with them. When viewing Jupiter, for example, we're reaching out across the universe some 675,000,000 kilometers. M 13 is around 25,000 light years away. M 31, M 32 & M 110 are some 2,500,000 light years away :icon_eek: . It's a wonder in itself that with a bit of 3" or 4" glass we are even able to contemplate such mind-bending displays of nature :smiley:

If you can, try to sit with your given object for a peaceful twenty or thirty minutes or so on your next observation session and I'm certain they'll be moments of greater clarity and seeing - even when viewing from a city. You really do notice that with practice and patience more detail can be tweaked. I think this 'slowing down' is a peculiar advantage enforced upon us as city viewers which by a curious twist of fate will serve us well when we up the aperture and get out to some really dark sites.

You see, in the city there doesn't seem a lot of sense running from one grey fuzzy to the next, all looking very much alike, so we must slow down, engage ourselves. By practicing this attentive sitting you come to notice more and more detail from the given object. Anything just glanced at will always look like a featureless something: an egg, a city wall, a tiled floor. But the trick is when out observing is to go beyond this and practice seeing - picking out features and textures.

But with all that said, pretty much in the city many DSOs are going to appear like differing brightnesses upon a similar grey fuzzy theme. Nevertheless, as can be seen with the above sketches, your best plan of action is to hunt out binary solar systems, open clusters, Jupiter and Saturn, the Moon and of course, in daylight, the Sun (obviously with the correct filters in place).

You've already displayed your ability of star-hoping and reading star maps (by finding M 13, M 31 etc) in the first place, so keep on practicing this skill in the city and when you get out to a dark site, you're going to find yourself wizzing about with ease.

Good luck and I hope this helped a little :icon_salut:

Edited by Qualia
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It's a wonder in itself that with a bit of 3" or 4" glass we are even able to contemplate such mind-bending displays of nature :smiley:

Couldn't agree more with this!

In one sentence you have summed up what this amateur astronomy lark is all about :grin:

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Those sketches are really nice accurate, great representation.

I live in a LP area too. W.r.t to M13 versus Andromeda I'd say this is often true but not always. I suppose it really depends how heavy the LP is and how good the sky is. Like last night, under very good conditions Andromeda spread out quite a bit with help of averted vision and all of M110 and M32 were visible also at this time, averted vision wasn't even needed to see m110 either. The one thing that you can do on M13 on the other had is really up the mag in a small scope such as mine ( again when conditions allow and it is high up near zenith). The two objects look very distinctive in their own way using suitable magnifications on them. On occasion I've been able to push M13 to view it with my 6mm eyepiece, and a certain amount of structure is revealed very nicely, it will not resolve to the core at that aperture, but for sure more than just a smudge, the little stars come popping out if you look for long enough :smiley: . On the other hand M31 never shows any fine structure in my scope, though it can get quite big when I just look away from it (with averted vision) and see some subtle/blurry variations in intensity away from the centre using low mag.

Skies are not that great where I am , for example I was unable to see some of the smaller stars in Ursa Minor, so I suppose that was around 3.5 naked eye magnitude perhaps at best ( without using a peephole/tube or thinking about it too hard. ) I also had the privilege of seeing M81/M82 last night, first time in ages and I was amazed how much that revealed, first time since I bought the BST eyepieces viewing that, perhaps also improved observing skills since I started, but they weren't that high in the sky, a beautiful sight.

As already said, all in all plenty fun to be had after having had really good sky conditions last night for a bit, it was a reminder how much can be seen in 4 - 5 inch aperture. A properly dark site/sky should make it even better.

Edited by AlexB67
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If you were using 50x then the equates to about 1 degree, M31 is 3 degrees across so you were chopping off 2/3 of it. Any light pollution and the arms disappear into it, especially if you limit the amount as you cannot tell where the outer arms actually start. Rather like looking at the central 1/3 of a person - can you tell where they start and stop?

You really need to be considering binocular fields of view for M31, I would say 5 or 6 degrees, which on a plossl is down around the 10x magnification. Until you start buying things like 82 and 100 degree eyepieces that is the area you need to consider. Then you should hopefully have enough of the emptyish universe aroung M31 to see the slight fog/mist that is the arms.

Try again with binoculars, is the obvious answer.

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M31 is one of those targets thats easy to see in any aperture and in my experience, from my back garden, looks pretty much identical in all scopes from a 3" refractor to a 14" reflector. Its a bright white core with a haze of light around it. There is only the vaguest hint of it's extended nature.

I can't wait to see this from a dark site with a wide angle, low magnification in a few weeks :)

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Thank you for these fantastic replies and sketches, very helpful indeed. Last night I was a bit limited for time so I was pleased to see these objects and it's nice to know that I did see Andromeda for the first time (2.5m light years - wow). Next time I will try to spend more time at the eyepiece on one object as suggested. I was surprised how much averted vision improved the view.

I'm really looking forward to Jupiter and orion coming back up high in the sky in the next few months - the views I had of these last year were excellent. Also I think I will spend more time on the moon as well. Regarding double stars I saw Mizar the other week and really liked this, so will try a few others. My brother lives in Devon so he may well get a visit from me with my brand new 120ed and i can see what M31 looks like then.

Gavin

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Ps I also forgot that I'm off to Gran Canaria in two weeks time and I'm able to take my scope with me, that could be an interesting experience.

Could be quite a moon-lit experience, I'm afraid - full moon is on the 19th...

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Indeed under light poluted skies I get similar results (I find it no less amazing to be able to see another galaxy millions of light years away though) but M31 is slightly oval to me here. Im hoping as the nights get darker and I get better eyepieces (Im still using stock SW 25 and 10) it will improve alot. The LP is the biggest issue though and I dont live in a city any where as big as London...

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