Does the Pinwheel actually exist?

[Starfazed]

Several times now I've tried to find M101 without success using 10x50 binoculars or my 150mm Skywatcher goto reflector under a clear Bortle 4 sky.

The two problems I have are knowing if I'm even close, and knowing if I'm looking at it without realising.

That might sound silly when I have a goto scope. The gotofunction is great for obvious celestial bodies like double stars or clusters - the object sought probably won't be in the centre of the eyepiece but as long as it's in the field of view of a low power lens (25mm so x30), I can slowly by remote control app move it to the centre.

That doesn't really work for feint objects though (or does it - any tips?) I might be looking for Neptune say, and there will be several equally feint stars in view, so which is Neptune? In that example I can usually work it out through colour and zooming in on Stellarium to work out which "star" is actually the planet.

But for feint objects like M101 that just doesn't seem to work. I've tried star hopping from Mizar to 81 Ursae Majoris, then 84, 83 and 86. I realise everything is upside down so as the scope moves west the eyepice view moves in a totally different direction. But then it all seems to peter out: HD122007 is nowhere to be seen yet should be close to 86 and midway between 86 and M101. With no 86, there's no M101. Or maybe I'm staring at it without realising. Am I?

I've used M101 as an example but other deep sky objects like nebulae or galaxies could apply too. I realise they won't be nearly as bright as M31 Andromeda, but it would be nice to think I can see and confidently identify more than one galaxy through a six inch scope. Or are my expectations set too high?

 

[Pixies]

A RACI finder really helps with star-hopping, as what you see matches the charts and the view moves as you would expect.

I've seen M101  in the finder view in a dark Bortle 4. Any brighter skies and this is difficult.

 

M33 (the Triangulum galaxy) was my bugbear. I spent hours and  hours frying to find it from home (Bortle 6). Both in the finder and also star hopping at the eyepiece. I know I was looking at just the right place. too. Then one trip to a dark site (B3) and it's visible on a small 30mm finder.

[Saganite]

Poor sky transparency can make nebulous objects difficult to find even in Bortle 4.

Edited August 14 by Saganite

[Elp]

Being bortle 7 this is my experience with every DSO target even something like m13. I've found I usually know I'm on target because the stars just seem to disappear and you're looking at a blank patch of sky, staring at it for a while then away from the centre of the eyepiece (so you're using averted vision) and the target appears out of nowhere. It only works if I'm certain via reference stars I'm on target which I do by using a wide 32mm and work down the powers slowly.

Otherwise for speed I use plate solving on a goto mount, target centred every single time.

[lunator]

I now live on a bottle 4 sky area. I had a quick look for M101 in my 15*70 just now. It was visible but very tricky. I found M51 much easier.

Keep trying using your scope, based on you using 10*50s It may be just beyond their capability to get M101.

Cheers

Ian

[dobbyisbest]

You can rest assured that you can see way more than one galaxy through a six inch scope, and your expectations are definitely not too high.Interestingly enough, you’ve mentioned two of the most difficult objects to find/see if one doesn’t know what to look for (M101 and Neptune), the other being M33. You also mention that “

 other deep sky objects like nebulae or galaxies could apply too”. So I have to ask, have you managed to see any other galaxies or nebulae with your scope in your skies?

If not, I would definitely recommend starting with easier objects to train your eye with and get a feel for what to look for.

For nebulae, currently, M27 and M57 are easy to see, and come December, M42.

For galaxies, look next to the M31 core for M32 and slightly further away for M110. You should just be able to fit all three into the FOV with your 25mm eyepiece in your scope. And then, at Ursa Major, look for M81 and M82 - small but bright visible galaxies that will also fit into your FOV.

Once you are familiar with those and can confidently find them each time you try, try M51 on the other side of Ursa Major. Much easier than M101, but a step-up in difficulty compared to the others. That’s where you really start to appreciate what sort of “whisp” and fuzziness you’re dealing with when looking for faint objects like M101 and M33. If M51 cannot be easily identified on any particular night, it’s not even worth trying for M101, in my view, because then the conditions are definitely too bad for it.

If you struggle with the easier objects listed above, I would seriously question the accuracy of scope alignment or the goto mechanics. An easy test that would leave no doubt is letting it find Vega or M13.

If you are in the UK, it is also worth noting that conditions haven’t been great over the last 2 years, and my second night with a really good sky this year was earlier this week and the other one on the 1st of April. Similar to what another poster said, suboptimal conditions can eliminate the benefits of Bortle 4 skies when it comes to DSOs. Patience, perseverance, practice and research are essential 🙂

As for Neptune, it was the most difficult of the outer planets for me to find and see initially (in larger scopes), and it just took a moment of good seeing whilst looking at a seemingly random star for a period to give me that ‘aha’ moment, but it definitely tests my patience. DSOs and the other planets are much more worthwhile and satisfying.

[Pixies]

This might be useful:

[PeterC65]

I've struggled to observe M33 visually and have only confidently managed it once. One of the things that makes M33 particularly hard I think is that there are no obvious bright star groupings within the field of view. I find it easier to be sure I'm looking in the right place (and I also have GOTO) when there are distinct bright stars in the vicinity and I can check on Stellarium.

I'd second the advice about starting with easier galaxies like M81 and M82 which I can always find. But I do find that galaxies are a bit underwhelming visually.

 

[globular]

This is what SkySafari says about M101 visually:

Quote

Although quite bright, at magnitude 7.9, M 101's large angular extent - some 22' across - gives it a low surface brightness, requiring dark skies to see. Only the central region of this galaxy is visible in smaller telescopes. Suggestions of the spiral arms can be glimpsed as nebulous patches in telescopes starting at 4 inches' aperture. A fairly large instrument, very dark skies, and a low power eyepiece are required to observe the spiral structure well.

I’m bortle 4.5 ish and usually see very little of it in my 8”. There are lots of much more satisfying things to look at, but I do go after it from time to time in the hope that one night it will wow me.

[Sunshine]

You’re not alone, I love under bortle 4 skies and have trained my 8” starsense dob on M101 on occasion without success. This is not an issue of not being on target, I aligned my starsense phone module on day one I took delivery of the scope and it has put each and every targed within the field stops for over a year now. Yet I failed to make out the pinwheel, I just gave up on it, it doesn’t exist. 

[Zermelo]

Keep at it. I started out with a 6"in B4 skies, and M101 isn't easy. Faint galaxies are a type of object that benefits a lot from experience. I have seen some that I definitely wouldn't have if they had been my first attempt, if that makes sense. Movement will usually help, so slow panning, as you describe, often makes the difference. Experimenting with magnification can also be beneficial. If it's too low, background light pollution may reduce the contrast to an extent that faint galaxies don't stand out; too high, and larger galaxies may fill the field and so be harder to distinguish.

[skyhog]

Don't feel too disheartened, I have often thought of M101 as one of the hardest on the M list. Lots of guides describe it as easy or bright, something it most definitely is not. I remember many fruitless nights searching for it with a mental image that bore little to its actual appearance. Stick with it.👍

[tomato]

If you have been trying recently I can say the recent ‘clear’ nights have been anything but from my location. Although bright stars are visible the sky has been plagued with consistent high thin cloud. Under these conditions objects like M101 and M33 will become very difficult.

 

[Starfazed]

Thank you all for the advice. I mentioned M101 mostly because it's quite high up, close to some very recognisable stars and variously described as bright or easy. Maybe with a 24 inch Dob!

Tonight sounds like it may be clear, so I may get to test out some of the other deep sky suggestions. The guides say thousands of things can be seen in a six inch scope, so I'm hoping for more than a few planets, the odd cluster or double star plus M31!

Maybe not the right forum to explain something else that has puzzled me, but obviously a long exposure camera on six inch reflector on an equatorial mount will reveal vastly more that what the eye can see. But if you're trying to take a long exposure of something too feint to see through the viewfinder, how do you know if you've pointed the scope at exactly the right bit of sky (and not accidently misaligned it by hitting the camera shutter!) before leaving it for a few hours to take the photo?

[tomato]

The problem of framing objects too faint to see visually was a big problem for me in the early days, I used to rely on recognising star patterns in the close vicinity of the object, but it was always a bit hit and miss.

These days, we have goto mounts that use star alignment and encoders to know precisely where the mount is pointing. Even better, we have a process called plate solving where the camera takes an image and then software compares the star pattern to a database of stars covering the entire sky and finds a match, all done in a couple of seconds if the mount knows roughly where it is already pointing. I take it for granted now that the scope will be centered on the object.

[Elp]

Plate solving as I've mentioned in my previous reply.

If you don't use a computer controller/software you can take an image of a starfield, upload the image to the astap website and have it plate solve the image and it shows an overlaid annotation of what's been taken. It's a workaround but much slower than using a computer controller controlling the mount and attached camera.

I'd be careful removing an eyepiece and camera constantly as you can misalign just by doing this, it's easier with a refractor/sct/RC as one of the things you can use is a flip mirror diagonal to switch between EP and camera without removing anything. Or just leave the camera in and plate solve and use your aligned finder to roughly point the scope. Note for successful imaging, especially at long focal length you need an equatorial mount driven in RA minimum, alt az is difficult and next to impossible for long exposure say longer than 10-15s per exposure.

 

Edited August 16 by Elp

[John]

Quite a few well known galaxies are listed as being quite bright - M101, M33 etc. The apparent magnitude figures quoted for such targets are misleading when it comes to judging their potential visiblity though because they are integrated figures for the whole object. The actual surface brightness of any one point across the object is often significantly lower than the integrated figure eg: while M101 is listed as having an apparent magnitude of 7.9, it's actual surface brightness across it's face is probably no brighter than magnitude 11 and probably fainter. This reduces the contrast of the target against the background sky markedly, making it much more difficult to actually see anything of it. Face-on galaxies are notorious for this as are some extended nebulosity type targets.

Any light pollution (man made or moon made) makes a big difference to the visibility of these targets. Dark skies can make a startling difference. 

Edited August 16 by John

[Paz]

M101 is not easy, I've tried and failed to see this many times. It's a case of trying to get together the best conditions you can and eventually you'll get it.

I think HD12207 is a good stepping stone to go for to find it but that being mag 7-8 means if that's not visible then M101 won't be. I think you would need to be able to see much fainter stars before m101 is possible.

[ollypenrice]

I never saw M101 in the UK.

As Zermelo says, movement makes faint, extended targets pop. 'Nod' the telescope back and forth on one axis. Any difference between true background and faint extensions should appear that way.

Olly

[Captain Scarlet]

I regard M101 as a more difficult version of M33. I lately moved from 20 miles from central London, Bortle 7ish or mag 19.1 to rural SW Ireland, Bortle 2-3 or mag 21.8. From the former, M33 and M101 were quite impossible through binoculars. M31 was possible but only as a hazy smudge. From Ireland, both are easily findable in 10x50 binoculars as obvious grey patches. Both seem to be bracketed by a trio of stars. However, on nights seemingly clear they can disappear entirely with just a small amount of poor transparency.

The one that to me is a galaxy that n’existe pas is IC342 aka “Hidden Galaxy”. I’ve tried and tried and tried through 56mm binoculars but no luck. Perhaps my new 70mm bins will do the trick.

And that moving the scope/FoV trick really does work!

Magnus

Edited August 17 by Captain Scarlet

[Richard N]

Interesting question. I was at a dark site for the Perseids the other day. The sky measured 21.07. With an 8 inch dob M101 was only just visible. I couldn’t see any structure during a short observation. I was initially quite surprised as it bright and spectacular using EAA. A quick google showed it has a low surface brightness. 

[Nyctimene]

The  "Uranometria Deep Sky Field Guide" gives values of surface brightness for M 33 with 14.2 mag, for M 101 14.9 mag, so considerably lower (and, interestingly, the same as IC 342). From my SQM-L 21+ (roughly equivalent to Bortle 4) observing site, the visibility of M 101 has decreased during the last years. Six years ago, I was able to make out the brighter core  region with a 7x50 Fujinon in (guessed) about 50% of observations, at least with averted vision.  Now, it's a rather rare sighting, I guess, due to increased air humidity and the maximum of the solar cycle. I'm hoping for some frosty and dry winter nights.

Stephan

Edited August 18 by Nyctimene

[ScouseSpaceCadet]

I've managed M101 just once. Last Autumn at Kielder with a 125mm ED refractor and 10x50 binoculars. It took a chilly, clear night at the darkest campsite England. Keep at it. 👍

[tomato]

I am a novice observer and have been trying out my recently upgraded 16” F4.5 Dobsonian from my Bortle 5/6 location. Using a Nexus DSC (which is a superb piece of kit BTW) to locate objects, M33 was just discernible by the gentle scope nudging technique, M101 is unfortunately currently behind my house.

Imaging can get around poor skies to a large extent, but I am coming to the conclusion that you really need dark skies for DSO observing.

[josefk]

On 14/08/2024 at 23:05, dobbyisbest said:

You can rest assured that you can see way more than one galaxy through a six inch scope, and your expectations are definitely not too high.Interestingly enough, you’ve mentioned two of the most difficult objects to find/see if one doesn’t know what to look for (M101 and Neptune), the other being M33. You also mention that “

 other deep sky objects like nebulae or galaxies could apply too”. So I have to ask, have you managed to see any other galaxies or nebulae with your scope in your skies?

If not, I would definitely recommend starting with easier objects to train your eye with and get a feel for what to look for.

For nebulae, currently, M27 and M57 are easy to see, and come December, M42.

For galaxies, look next to the M31 core for M32 and slightly further away for M110. You should just be able to fit all three into the FOV with your 25mm eyepiece in your scope. And then, at Ursa Major, look for M81 and M82 - small but bright visible galaxies that will also fit into your FOV.

Once you are familiar with those and can confidently find them each time you try, try M51 on the other side of Ursa Major. Much easier than M101, but a step-up in difficulty compared to the others. That’s where you really start to appreciate what sort of “whisp” and fuzziness you’re dealing with when looking for faint objects like M101 and M33. If M51 cannot be easily identified on any particular night, it’s not even worth trying for M101, in my view, because then the conditions are definitely too bad for it.

If you struggle with the easier objects listed above, I would seriously question the accuracy of scope alignment or the goto mechanics. An easy test that would leave no doubt is letting it find Vega or M13.

If you are in the UK, it is also worth noting that conditions haven’t been great over the last 2 years, and my second night with a really good sky this year was earlier this week and the other one on the 1st of April. Similar to what another poster said, suboptimal conditions can eliminate the benefits of Bortle 4 skies when it comes to DSOs. Patience, perseverance, practice and research are essential 🙂

As for Neptune, it was the most difficult of the outer planets for me to find and see initially (in larger scopes), and it just took a moment of good seeing whilst looking at a seemingly random star for a period to give me that ‘aha’ moment, but it definitely tests my patience. DSOs and the other planets are much more worthwhile and satisfying.

Packed with excellent advise - most particularly having a few reference objects per season to assess the quality and viability of the night (or site) before going after tougher targets. Well worth making an ingrained practise (i wish i remembered to 🤣).

Edited September 2 by josefk