Struggled with M32 and M33

[MimasDeathStar]

Hello all - I just wanted to double check the experience of others if at all possible to make sure that I am not doing something daft!

I was out last night braving the cold for a couple of hours and was looking for Messiers more or less overhead around Andromeda.

I'm using my Meade 70/900; I found M31 easily enough and M110 too although neither really jumped out. I expected a little more from M31 to be honest but that's probably a case of expectations vs reality! I could definitely make out a central core and occasional fleeting glimpses of the elongated shape - but I just couldn't pick out M32 at all.

I have a feeling I may have needed more magnification - I tried 40, 25 and 15mm. With the 15mm M31 took up a good portion of the fov but was so vague and smushy I struggled to pick anything out. Is this normal, have any of you struggled with M32.

Similarly with M33 I got nowhere. I just couldn't pick it out at all. I had moments where I suspected there was something there - and I know I was in more or less the right area, but just couldn't bag it which was a shame. Looking at star charts when I came back in I realised it actually might be a bit bigger than I'd realised. I think I was looking for something smaller. I'm in Bortle 5 ish skies (4 end of 5 rather than 6 end of 5 if you know what I mean!).

When you order the Messiers by apparent visual magnitude M33 seems to be around M71/M56 brightness - and they were a real stretch for me so maybe I need a trip to darker skies!

Many thanks all.

[Stu]

M32 is pretty small, and can look like fuzzy star at lower powers. Understanding the scale of the image you are viewing through the eyepiece is essential to working out exact where to look. The size of M31 will vary depending on the darkness of your skies. Under light pollution, you just see the central core, and M32 and M110 can seem a long way from it. Under dark conditions you see more of the main galaxy so they appear closer. So, if you calculate your field of view then it is easier to see where to look for M32.

M33 has very low surface brightness ie its magnitude is spread over a much larger area than some other objects, so it appears much fainter. It gets washed out easily with light pollution. Under a dark sky it is easy even in binoculars, but you will struggle with a scope under LP.

Surface brightness is a very useful concept to understand in order to work out which objects are likely to be easier and which ones harder.

[jetstream]

41 minutes ago, MimasDeathStar said:

maybe I need a trip to darker skies!

This is the main issue IMHO, my 90mm scope shows it nicely, M33 that is. BTW M33 can be kind of hard IMHO.

[John]

Its more likely that you saw M32 rather than M110. The latter object can be challenging with 100mm of aperture unless the sky is really dark.

As Stu says, M33 is faint, extended and hard to see despite what it's integrated magnitude figure (6.7 I believe ?) would have you believe. Again easy to overlook with a 100mm or larger aperture if you don't know just where to look and what to look for.

Low power generally is the key to these particular targets.

[Marvin Jenkins]

You are in good hands with Stu, no truer word spoken when it comes to the heavens. I can only add that I have many opportunities to view M31 and up until recently they were much like your own.

I think I was eager and trying to hard. I had no idea how big that galaxy is and I was concentrating on the core thinking ‘that’s it’ It was not until I got a really dark night with great seeing and a wide field eye piece that I realised it was still bigger than the field of view.

M

[mikeDnight]

M31 & M32 are relatively easy, so I'd imagine you saw M32 rather than M110 which is the more difficult of the three. Having said that, all three galaxies are within the grasp of a 70mm scope, but wide field instruments and low to medium magnifications work best. Often, a medium power wide field eyepiece will give a more contrasty view because the sky background becomes darker with increased power. But too much power will kill it! Binoculars or rich field telescopes give the best view of the Andromeda trio. M33 on the other hand is large and face on, which makes it a difficult target in less than dark transparent skies as we're looking through the galaxy rather than at it edge on. Large scopes will show it well, but in a 70mm you're going to struggle with M33 on all but the best nights.

Below is a field sketch through a 128mm refractor of M31 centre, M32 lower right & M110 top. M110 is by far the more difficult of the three but still within reach of a 70mm.

 

Below is a sketch of M33 as seen through a 100mm refractor on a night of good seeing. (Bortle 6ish)

Edited November 30, 2019 by mikeDnight

[Stu]

27 minutes ago, John said:

Its more likely that you saw M32 rather than M110

That makes alot of sense John. With just the core showing, M32 would appear further away and probably more like M110's position without careful checking. I agree about M110 being much more difficult from light polluted skies.

[joe aguiar]

not much more to add cause u got most of the answer but I think u need lower powers than u have, and lp can also play a big part.

Joejaguar 

Edited December 1, 2019 by joe aguiar

[MimasDeathStar]

Thanks all that's very helpful - yes it looks like it was definitely M32 that I found not M110 so thanks very much for the clarification; I think I was expecting it to be closer for some reason but the penny has dropped - I've been using astrophoto's as a  guide and of course they'll be showing the fainter extended regions too.

@joe aguiar thanks but I'm already using a 40mm plossl and my scope only has a 1.25" focusser so that is as low as I can physically go I think!

[Stu]

In theory this is your field of view, the scale should be correct but obviously M31 will appear much smaller than this as you will only see the bright core. M32 looks like a fuzzy star to the right and slightly below the centre of the core. M110 is more obvious in this chart to the left, but in reality is easily washed out by LP. The chart is shown left right reversed to match a refractor view with mirror diagonal and the blue circle is 1.9 degrees which should match the 40mm plossl in your scope.

I've added M33 in there too, although this probably won't be too much use. It just gives an idea of scale, but really it just looks like an oval glow unless under very good skies. Then you can pick out some detail and even nebulae within it such as NGC604, but that does need a largish scope and good skies.

[joe aguiar]

1 hour ago, MimasDeathStar said:

Thanks all that's very helpful - yes it looks like it was definitely M32 that I found not M110 so thanks very much for the clarification; I think I was expecting it to be closer for some reason but the penny has dropped - I've been using astrophoto's as a  guide and of course they'll be showing the fainter extended regions too.

@joe aguiar thanks but I'm already using a 40mm plossl and my scope only has a 1.25" focusser so that is as low as I can physically go I think!

what u need to remember in most images its a very low power shot to fit the whole m31 in the frame, m31 is really big most people dont understand that but since most of us are in lp zones even semi lp zones you dont see the whole thing. Same goes for m42 visial its is bright BUT its only through photos that what u saw visually is 1/10 what the camera got in longer exposures.

anyway so m31 is best through short tube scopes where you can get 3 to 5 degree fov. even looking at m31 in a grey zone iam sure iam not seeing the full extend of it cause  our eyes just cant collect the light and hold on to the image BUT the camera can capture that low light and build that image over time. so when u see it in a pic thats very low power so even your scope doing 23x power. that seems low and it kinda is BUT a 40mm ep at 1.25" will have a fov of 44 fov so the  m110 galaxy may even be at the edge of the ep and u may not be thinking thats it cause your expecting it to be close like the pics are.

hope that makes sence to u

joejaguar

[joe aguiar]

1 hour ago, MimasDeathStar said:

Thanks all that's very helpful - yes it looks like it was definitely M32 that I found not M110 so thanks very much for the clarification; I think I was expecting it to be closer for some reason but the penny has dropped - I've been using astrophoto's as a  guide and of course they'll be showing the fainter extended regions too.

@joe aguiar thanks but I'm already using a 40mm plossl and my scope only has a 1.25" focusser so that is as low as I can physically go I think!

the 40mm has a fov of 43 or 44 depending on your ep

a 32mm super plossl will have a fov 52 fov, so having the 40 almost doesnt make it worth it to have

there are some items like m45 also that you wont see whole thing

what u could do sell the 40mm ep or trade it for something like a 32mm 1.25" but 70 degree fov for those large stuff or sell both the 32 and 40mm and just one 32mm ep with a wide fov then u only need that one and not 2 of the same focal length

joejaguar

[Stu]

7 hours ago, joe aguiar said:

the 40mm has a fov of 43 or 44 depending on your ep

a 32mm super plossl will have a fov 52 fov, so having the 40 almost doesnt make it worth it to have

there are some items like m45 also that you wont see whole thing

what u could do sell the 40mm ep or trade it for something like a 32mm 1.25" but 70 degree fov for those large stuff or sell both the 32 and 40mm and just one 32mm ep with a wide fov then u only need that one and not 2 of the same focal length

joejaguar

Joe, I was thinking about posting something similar, even suggesting a 24mm 68 degree eyepiece until I checked the scope specs. A 70mm aperture, 900mm focal length scope is f12.8. The exit pupil with a 40mm eyepiece is only 3.1mm, going to a 32mm takes it to 2.5mm and 24mm would be 1.9mm. I suspect that, although there are no field of view gains to be made by using the 40mm the additional exit pupil will help brighten the image without the sky background being excessive under the LP. I've found 40mm eyepieces to be useful in Maks for similar reasons, particularly for filtered views with UHC or OIII filters.

My 72mm scope by comparison is f5.9 and with a 32mm Plossl in it I would get a 5.4mm exit pupil and 4mm with a 24mm.

[wookie1965]

I have never seen M32 and M110 looking at M31 in my 5" refractor from my light polluted sky and M33 even when I had my 8" i never saw it. I went Scotland last October to the Galloway meet and saw M33 by eye it was that clear unbelievable sight.  

[John]

Galaxies and nebulae (with some notable exceptions) can be hard work with a 70mm aperture scope, especially if you have some light pollution to deal with.

If you want to rack up some Messier and NGC objects then open clusters and the brighter globular clusters will prove more fruitfull I think. I managed to see loads of open clusters with my old Tasco 60mm refractor

 

[MimasDeathStar]

Thanks all - honestly I cant thank you all enough for the advice.

I've got the full set of Series 500 Plossl's from Opticstar, I bought some of them and then just kept buying until I had them all. I can't comment on how good they are quality wise but I do know that they are a massive step up from the eyepieces that came with the scope so I'm happy. And I managed to get them all for less than £100 so I was pretty pleased.

@Stu@joe aguiar the 40mm and 30mm have a fov of 45 degrees I think - but as you've deduced that is still wider than the maximum fov that my scope can see. I use the 40mm a lot as I really like it but use the 30mm very rarely as it seems to be the weaker of the set with quite a narrow "window" with which to see through. The 25mm is good because it darkens the sky quite a bit which is handy for contrast I've found. But unfortunately I've already gone way beyond the maximum fov my little scope can handle. 

Here's a quick drawing I took at the eyepiece - maybe someone can deduce it for me! It was fairly near the zenith so I think probably that east is up?

Thanks again all.

 

Edited December 1, 2019 by MimasDeathStar

[MimasDeathStar]

1 hour ago, wookie1965 said:

I have never seen M32 and M110 looking at M31 in my 5" refractor from my light polluted sky and M33 even when I had my 8" i never saw it. I went Scotland last October to the Galloway meet and saw M33 by eye it was that clear unbelievable sight.  

Thanks that's reasuuring - it is quite bright where I live so maybe I'll just have to cross it off the list for now until I get further away!

[Stu]

1 hour ago, MimasDeathStar said:

40mm and 30mm have a fov of 45 degrees I think

Normally 40mm Plossls are around 42 or 43 degrees and 32mm 50 or 52 degrees, those are the limits within the field stop of 1.25" eyepieces.

[MimasDeathStar]

1 hour ago, Stu said:

Normally 40mm Plossls are around 42 or 43 degrees and 32mm 50 or 52 degrees, those are the limits within the field stop of 1.25" eyepieces.

 

 

Yes thank you good point - I checked they are both 40 degrees