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What would be the optimal setup for me to watch andromeda?


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Hi, I got a skywatcher 200p with EQ5 goto, I was wondering what would be the optimal setup I could use to achieve a nice view of andromeda. I've actully seen it only once, but only the bright fuzzy core from a light polluted area, so that doesn't really count.

Anyhow, my telescope is f/5, and the lowest magnification eyepiece I have is 25mm 52 degrees wide angle eyepiece, which should result in the following view:

https://astronomy.tools/calculators/field_of_view/?fov[]=41|849|||1||&messier=31

I wouldn't say that it's that bad, but I wonder if there might be better options for me.

The thing here is that observing the andromeda galaxy is hard by itself, I wonder if getting a lower magnification eyepiece would make it better or worse.

So the options I thought of were either getting a 25mm eyepiece with wider angle, getting a lower magnification eyepiece(such as 30-40mm), or maybe even a barlow reducer?

Since I have no idea about the consequences of these actions, I'm coming here for some advice, what would be the best way for me? :)

I'll obviously add that I'll plan on using it in a dark site, not expecting to see anything in a light polluted area no matter what eyepiece I'll use ^_^

Thanks.

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I've read some articles to the contrary, but in my personal opinion, lower magnification will be most beneficial as it will "concentrate" those precious few photons from lower surface brightness objects into a smaller area.

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Alot depends on the skies you can get to. Under a really dark sky it is worth having the widest field you can get so you can start to see the outer arms and get M32 and 110 in the view. If you are not under good skies then all you will get is a washed out view and would be better off at slightly higher powers.

What sort of budget would you have?

The APM 20mm 100 degree would give you 2 degrees of sky with a 4mm exit pupil, quite nice. An ES 30mm 82 degree would be nearly 2.5 degrees with a 6mm exit pupil, nice under very dark skies but perhaps washed out if you have LP.

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2 hours ago, Buzzard75 said:

I've read some articles to the contrary, but in my personal opinion, lower magnification will be most beneficial as it will "concentrate" those precious few photons from lower surface brightness objects into a smaller area.

Thanks :)

1 hour ago, Stu said:

Alot depends on the skies you can get to. Under a really dark sky it is worth having the widest field you can get so you can start to see the outer arms and get M32 and 110 in the view. If you are not under good skies then all you will get is a washed out view and would be better off at slightly higher powers.

What sort of budget would you have?

The APM 20mm 100 degree would give you 2 degrees of sky with a 4mm exit pupil, quite nice. An ES 30mm 82 degree would be nearly 2.5 degrees with a 6mm exit pupil, nice under very dark skies but perhaps washed out if you have LP.

So starting with the budget, I don't know really, I can pretty much buy only in aliexpress/ebay/amazon(shipping is costy though)/other sites with free world-wide shipping, but I believe the eyepieces you stated above are way beyond what I'd want to spend on an eyepiece, as I probably have more efficient things I could buy with that money other than eyepieces(such as saving for a better mount or whole setup).

Are there any other suggestions maybe? BTW, I'll be using the eyepiece under very dark skies, according to https://www.lightpollutionmap.info, a value of around 0.10-0.20.

What would you say about this 27mm 70 degree eyepiece? https://www.aliexpress.com/item/32843410445.html?spm=2114.search0104.3.59.97f630b8oGMAwA&ws_ab_test=searchweb0_0%2Csearchweb201602_5_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536%2Csearchweb201603_60%2CppcSwitch_0&algo_expid=956fd08d-5a06-45b3-b974-1fc896cc5662-7&algo_pvid=956fd08d-5a06-45b3-b974-1fc896cc5662

Or maybe this 30mm 80 degree eyepiece? https://www.aliexpress.com/item/32799918929.html?spm=2114.search0104.3.123.97f630b8oGMAwA&ws_ab_test=searchweb0_0%2Csearchweb201602_5_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536%2Csearchweb201603_60%2CppcSwitch_0&algo_expid=956fd08d-5a06-45b3-b974-1fc896cc5662-15&algo_pvid=956fd08d-5a06-45b3-b974-1fc896cc5662

Edited by msacco
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Hi masacco,

It depends more on Viewfield also, not only magnification. To get andromeda in your EP you'll need a 2" EP with panorama view (about 100°), just take a look on this photo: 

Best regards, 

F96345F9-90F0-49AF-A3DF-F0869652083A.jpeg

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16 hours ago, OJ87 said:

Hi masacco,

It depends more on Viewfield also, not only magnification. To get andromeda in your EP you'll need a 2" EP with panorama view (about 100°), just take a look on this photo: 

Best regards, 

F96345F9-90F0-49AF-A3DF-F0869652083A.jpeg

Sounds like it will be too costy to get such eyepiece only to see andromeda I guess(maybe some other targets as well? I guess most objects are much smaller), it could be worth investing into that some day, but currently I probably have some better equipment I could use it for :)

5 hours ago, MarsG76 said:

What about large aperture binoculars on a tripod? Surely that would be a great view of M31.

 

Hmm, what would count as large aperture binoculars? This will probably be quite costy as well isn't it?

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Can I be a bit contrary here and suggest something around 14mm-17mm?

This object is so bright that it takes more mag very well, espc under dark skies. The darker the sky the more it grows.... I absolutely quit trying to get it all in the FOV at once, and concentrate on the many features it offers along its course.

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I suggest just go with the 25mm eyepiece you've got, and then decide if it's worth spending out for another eyepiece. Since you have GoTo, you can centre the companion galaxies M32 and M110 - in a photo M31 extends out to these, but most likely not visually.

Visually the satisfaction lies mainly in finding a fuzzy blob representing the central part. 

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My best all encompassing views in a 200mm f6 Newtonian/Dobsonian are with a 2" 38mm SWA at 6.3mm exit pupil and this still does not totally envelope the entire galaxy but I consider myself a cheap eyepiece specialist and this does provide awesome views in this scope  in bortle 4 or less skies. In skies that have more light pollution or if ground level light pollution prevents or limits dark adaptation your 25mm and centering M31,32,110 is likely the best route as stated previously because using a wider field lower mag eyepiece will not show you any more galaxy but the 38mn SWA can be very inexpensive and will do a very nice job with M42 and M45 even in more light polluted skies and is a great finder eyepiece in that scope but at f5 it will show a little more coma than at f6 that being said using widefield low mag eye pieces in newtonians requires good collimation or the edge views can be just horrible.

A good pair of binoculars and a trip to the countryside will provide the best views of M31 though so if you do travel to a dark site binoculars are invaluable and a great addition to the experience.

Best of Luck and Clear Skies of course 😉  

                          Freddie.

 

Edited by SIDO
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7 hours ago, Alien 13 said:

Andromeda is huge, it spans a distance greater than 6 moon widths so you  are only ever going to get it all in low power binoculars...

Alan

That's not actually true Alan. A decent widefield scope could give you from 3.5, possibly up to 5 degrees of sky which is enough to fit it in. My old Genesis will do it, at 500mm focal length and plenty others out there too such as the skywatcher 120mm f5 achro with a 2" eyepiece in it; that's where some of these achro scopes will shine, on low powered, widefield views.

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1 hour ago, Stu said:

That's not actually true Alan. A decent widefield scope could give you from 3.5, possibly up to 5 degrees of sky which is enough to fit it in. My old Genesis will do it, at 500mm focal length and plenty others out there too such as the skywatcher 120mm f5 achro with a 2" eyepiece in it; that's where some of these achro scopes will shine, on low powered, widefield views.

Here it is with a Revelation 32mm 1.25 52° eyepiece at a 6.4mm exit pupil...

Orion ST80 Achromat...400mm focal length...

First time I posted an Astronomy Tools Fov link hope it works 🙂

https://astronomy.tools/calculators/field_of_view/?fov[]=318|185|||1||&messier=31

                          Freddie.

Edited by SIDO
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1 hour ago, Stu said:

That's not actually true Alan. A decent widefield scope could give you from 3.5, possibly up to 5 degrees of sky which is enough to fit it in. My old Genesis will do it, at 500mm focal length and plenty others out there too such as the skywatcher 120mm f5 achro with a 2" eyepiece in it; that's where some of these achro scopes will shine, on low powered, widefield views.

You are right that a widefield scope using low powers will fit it in but still feel that some observers under estimate its size and start looking "through" it with to much magnification....

Alan

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50 minutes ago, Alien 13 said:

You are right that a widefield scope using low powers will fit it in but still feel that some observers under estimate its size and start looking "through" it with to much magnification....

Alan

'Tis true. I recall the first time I viewed it was through probably the least appropriate scope; 200mm f10 Mak ie 4000mm focal length and it gave around 0.7 degrees fov. I don't know any better at the time but was quite underwhelmed by the view, understandably!

My best views have been under decently dark skies in Dorset, with the Genesis giving around 5 degrees of sky. With good dark adaptation you can really see the huge extent of it.

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I would say anyone reading this thread that has not seen M31 through binoculars or a low mag wide field 7 to 14x achro ed apo under dark skies really should get that one off the bucket list or put it on theirs, really is a stunner and while your out there hit M42, M45 and the doulble cluster all on the same night you won't be disappointed in the slightest I guarantee it 😉  

                       

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One of the interesting things about M31 is how larger apertures makes it "grow" in size extensively, and conversely smaller in smaller apertures, even from dark skies. I guess the extra mag at enough eye illumination that the right big scope (fast) enables seeing the fainter outer sections. From the best of nights I can see M31 with a core brightening naked eye. The 200mm f3.8 gives a really interesting low mag view of M31 at 2.75 deg or so and 29x and I would love to try one of Mel Bartels fast newts on it. The view is completely different from a low mag refractor view. This 200mm scope also makes it "grow".

Edited by jetstream
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Off topic a bit but here is Mels sketch with the 150mm f2.8 and shows what I mean about the galaxy growing, but possibly the galaxy ends and IFN starts? but where lol! I can see parts of this but not as extensive as this (yet).

image.png.06cb91d6b92acb6e2256b1797f4bc87b.png

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  • 4 weeks later...

M31, the Andromeda Galaxy, will always only be a little white blob.

 

- Dark skies: naked eye detectable with averted vision

- Dark skies: golf ball like in binoculars

- >= 8" Telescopes, one can see the golf ball like core and some swirling around the galaxy's core.

If you want more, you need astro photography.

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1 hour ago, Ags said:

@darkskyastronomy how dark were your dark skies? From a semi-rural location in Welsh Valleys with binoculars I have seen central core plus faint disk extending to either side, and traces of structure in that disk.

I agree. From a dark site with binoculars or a widefield scope, and with good dark adaptation there is certainly something to see outside the core. It is subtle but definitely observable. The dust lanes can be detected too, I saw one of them when observing with my 14" from Bignor.

Of course M32 and M110 are also quite easy from a dark site.

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The Andromeda group is a very good target for someone starting out to explore, yet will require time gaining familiarity with the characteristics that this subject will visually convey. Observed at a light polluted site, M31 will mostly just be a brightish central core with some indication for extended haze. At a dark location, with good transparency, it is completely transformed and as many have already mentioned, is a fantastic binocular object to observe. The vast expansive haze revealing subtle hints of dust lanes outstretch the field of view from a wide field observation in a variety of instruments. It can become comparable with images and not at all golf ball only in resemblance. Hand held binoculars with a steady posture are fine, mounted onto a monopod better, it is bright and a good subject for newcomers to look at if at an astro society dark site, along with M32 and M110 in or near to the same field of view. 

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24 minutes ago, darkskyastronomy said:

Stu + Ags

Thanks for your input.

You need to make some concessions, as I believe the thread starter is still inexperienced, so will not see as much 🙂

Plus without holding binoculars totally still, seeing faint details is really difficult.

 

Thank you for your advice darkskyastronomy ;)

I always think it worthwhile highlighting what is possible to observe so that any new starters to the hobby know what is achievable with practise and the right conditions.

We also do not know the OPs age; young eyes can very easily pick out faint objects which challenge old folk like myself :)

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