M101 - difficult to observe or just me?

[JulianFR]

It took me a long time to find M101 last night. Obviously Ursa Major is high, so not ideally placed for the Dob, plus the sky though it gave me very clear spells also seemed 'watery' compared with Friday night. But I had expected M101 to be more evident. When I eventually found it I was surprised what a faint smudge it is, though large.

I could not make out much structure at all and it didn't seem that magnification above the 24 and 18mm I used was much good.I observed for around 20 mins, though I realise that's probably not long enough.

I do still struggle to find DSOs ... They are invariably much fainter than I expect. Is it just me though with M101 or can other people make out the structure?

I didn't see much structure in M51 actually, above the two cores. Though as I observed for longer I did start to see more structure come in.

Still, I had good views of M3, M13 and the Ring Nebula last night. Those I can find easily too!

[Luke]

I have a few times made out decent structure in M101 with a 12 inch dob under okay skies. A lot of the time, I can see it is there but can barely make out structure. Keep coming back to it, it will be well worth it if you catch it on a good night

[scarp15]

Yes it is one in which you need to keep going back to. Although very favourably positioned at the moment (though a little awkward to position with a dob), it does require a dark sky and dark adaption. Once you have located you can gain in familiarity. In terms of structure, it is subtle and requires time and trying out varied eyepieces. Permitting your eye to relax, employing perhaps averted vision to.  

[Knight of Clear Skies]

I haven't had many chances to look at DSOs through a scope, but galaxies are faint objects with low surface brightness, so I don't think it's just you. If you are seeing any structure then you are doing pretty well. To put it in perspective, the first person to see the spiral structure of a galaxy (M51) was Lord Rosse, and his telescope looked like this (for scale, notice the man standing on the platform):

In many ways your 12" dob is a superior instrument, with a more reflective coating on the primary.

M101 is quite large but its surface brightness is lower than M51, making it harder to see detail. I imaged it a couple weeks ago, and even with a very fast lens (f1.8) it just showed up as a fuzzy blob in individual subs, I had to stack a few minutes worth of data to see it as a spiral. To see it in real time would definitely be challenging.

Good luck with it, anything that faint is going to be very sensitive to the seeing conditions.

[swamp thing]

I've see the spiral structure in M101 when observing from Salisbury plain. Fantastic sight, one of the moments that stays with you in the hobby.

[Moonshane]

it is very faint and more expansive than M51 so a lot harder to see the spirals. but from a dark site with a 12" scope I'd expect you to do so.

the key sentence in your OP is "Though as I observed for longer I did start to see more structure come in.".

[NGC 1502]

For me, M101 is tough from my light polluted back garden, using a 10" Dob.    I can be looking at it, think it's not there, then as I keep looking, suddenly realise that there's a big fuzzy blob.....

One good way to bag it is to star hop from Alcor / Mizar  http://www.ne.jp/asahi/stellar/scenes/object_e/m101.htm  scroll down to see that.

Regards, Ed.

[Northern Soul man]

Hi Julian, I think the title of your thread has been said by nearly everyone who observes under light polluted skies!! - I mainly observe under light polluted skies - its the problem of the conditions we observe under and not the individual - there's been many a night where the object has been in the centre of the FOV and "nothing" - its purely down to the background sky being washed out by the level of light pollution - there's been the odd night over the last few years - I do mean the odd night - some nights I struggle with M1 and other nights its there - just down to sky conditions.

Paul.

[dick_dangerous]

M101 is a real pain in the backside - really faint and diffuse. I don't look for it in London because our skies just ain't dark enough. You want a good, clear, dark night to see it, then its relatively easy. It was pretty clear in my 6'' and visible in my 3'', so with a good night and 12'' of aperture you shouldn't have a problem.

DD

[JulianFR]

Thanks everyone... I'm glad it's not just me and it can be a challenge, though I do realise I should have persevered for longer st the EP, certainly for as long as I did with M51. I will certainly be going back for more attempts. I guess as a beginner I forget how faint and low magnitude most of these DSOs are, and that they don't all jump out at you like M3 or M13! I do get s real buzz when I eventually track one down though.

There's an annoying streetlight in my little close, just a few yards away, and others streetlights close by (considering I live in the semi-rural outskirts of a small market town it's pretty frustrating) ... The orange glow is intrusive when I observe to the W and SW, but I thought it was ok looking straight up, ie to Ursa Major. But maybe it is having more of an effect than I realised.

Rosse's telescope was amazing... The biggest till Mount Palomar was built??? What must it have been like though not being able to steer it? I think it could only move in altitude couldn't it? Does that mean there would be things he could never observe, or would everything in the N hemisphere have moved in front of his scope eventually?

[NGC 1502]

Thanks everyone... I'm glad it's not just me and it can be a challenge, though I do realise I should have persevered for longer st the EP, certainly for as long as I did with M51. I will certainly be going back for more attempts. I guess as a beginner I forget how faint and low magnitude most of these DSOs are, and that they don't all jump out at you like M3 or M13! I do get s real buzz when I eventually track one down though.

There's an annoying streetlight in my little close, just a few yards away, and others streetlights close by (considering I live in the semi-rural outskirts of a small market town it's pretty frustrating) ... The orange glow is intrusive when I observe to the W and SW, but I thought it was ok looking straight up, ie to Ursa Major. But maybe it is having more of an effect than I realised.

Rosse's telescope was amazing... The biggest till Mount Palomar was built??? What must it have been like though not being able to steer it? I think it could only move in altitude couldn't it? Does that mean there would be things he could never observe, or would everything in the N hemisphere have moved in front of his scope eventually?

Is it possible to erect some sort of shield to block the light from at least the worst of the streetlights ?   I don't have any street lights visible from my back garden, but I use tarpaulins to block nearby house lights, only takes a minute or two to put them in place.

If the streetlights are shining into a bedroom, some local councils will put a shield on the light itself, don't know if that's an option for you, but worth a thought perhaps.

HTH, Ed.

[johnd]

In my naivety being a newbie, I spent several hours star hopping to this DSO and as I couldn't see anything went back and did it all again   I now know I'm unlikely to see this one in my current skies and plan to go to a dark(er) site to see or attempt to see several Messier objects I have in mind. I did see M13 early morning Saturday and was chuffed!

[Mike73]

Yep thats the way, if you cant see M101 then you just need to go to darker skies. Simple as that.

[Northern Soul man]

Nice 1 guys, Another thing you could try before any permanent shielding is such a simple piece of kit - see if you have a dark blanket or a piece of thinner dark material - it must be quite thick as not to let any light in and just place it over your head and drape it over the EP (whilst your looking through it) and surrounding area - you will be amazed how much this will help the contrast at the EP, try and tuck it around the tube if you can - then concentrate at the EP - this will make certain objects visible - I'm not saying its a cure for LP - but it helps.

  Another thing is to try to select objects that have a overall smaller surface area - magnitudes can be a little off putting as they are measured as a single point of light - like a star - but as we all know these objects can be spread over larger area of sky - so this lowers the overall surface brightness - as an example try to compare the brightness of - say a planetary nebula - there's a few about the Eskimo, the Blinking planetary - then check it against a larger Galaxy of the same brightness - I bet you will pick out the Planetary a lot easier than the galaxy - the Blinking planetary is a great example of this as you have a reference star very close to the actual planetary - low mag will make them look like 2 stars - but as soon as you increase mag and use averted vision - the Planetary will "blink" at you, so due to the compactness of the Planetary covering a lot less sky than an extended Galaxy, the Planetary will look a lot brighter.

So under light polluted skies I tend to look for the smaller brighter objects rather than the larger extended objects, as said Planetaries, smaller galaxies, globulars - you get the picture.

Paul.

[Knight of Clear Skies]

This handy illustrated guide to DSOs also lists them by surface brightness, which is a generally better guide to visibility than magnitude.

[michael.h.f.wilkinson]

M101 is quite hard due to the low surface brightness. Under very good skies I have been able to make out the spiral structure with my humble C8, however. Conditions are everything. On good nights, I can make out M101 in bins readily (10x50), so it is not as difficult as some others (Cave, Flaming Star, California), but coming from M51 (let alone M81/M82) it can be very hard.

[JulianFR]

I plan to contact Wiltshire Council about the streetlight... It is the other side of the road from my house but to be honest I didn't bother about it till I started astronomy seriously :-O Not sure that my couple of neighbours would want the light switched off at night. A shield of some kind would be worth asking about.

Also, I was thinking about making a shield of some kind out of a camping MST... To fix to the side of the open tube on the same side as the streetlight. That should keep the glare out, but I don't know if it would help the overall LP sky glare.

To go back to one of my original questions, I assume magnifying M101 in the hope of identifying structure would not work because of its low surface brightness. Certainly I didn't feel that anything stronger than my lowish power 24mm and 18mm would show more.

[Northern Soul man]

Hi Julian - nice 1.  I think that the majority of astronomers come into this with the hope of seeing structure/spiral arms in many of the Galaxies we see in the night sky.  We are all the same and I think that frustration plays a major part in a lot of the questions we see on here - wether it be about structure in Galaxies or just the lack of detail in the Planets - the major problem is looking and not seeing - the frustration begins to build - as you say you haven't even thought about the street lighting until you were an Astronomer, its only when we look up (being an astronomer) we begin to question what we can exactly see  - I would say that 99% of the questions wouldn't even be asked if we lived a few hundred years ago, with the equipment  and knowledge we have now, you could probably look up and see the Milky Way arcing across the sky - no lights as such - just a pitch black sky and even a good quality 4" scope would be all that you would need - not so much on the Solar System/planets, but the rest of the universe would come alive for us all - spiral arms, mottled structure in the spiral arms being able to properly define barred spirals and just wandering whats in that massive elliptical Galaxy.  I just think there are Astronomers out there that actually live under very dark/clear skies in the middle of nowhere and have near photographic views of the Planets/Galaxies - seeing detail and structure - but its just down to the dark skies and not the individual.

I think its purely down to the light pollution and just not being able to see the Galaxy after taking time to star hop/judge distance in degrees.  I have always observed from the light polluted skies in the West Midlands with a little less than Mag 4 skies - some nights I can make out M1 - other nights its totally invisible.

It would be nice to hear from someone who has very dark skies to observe under and just let us know what they can see through any given instrument - just going to show that IT IS just the sky conditions that's holding us back.

Keep us informed of how you get on Julian - don't be dis - heartened and enjoy your gazing mate.

Paul.

[Knight of Clear Skies]

Rosse's telescope was amazing... The biggest till Mount Palomar was built??? What must it have been like though not being able to steer it? I think it could only move in altitude couldn't it? Does that mean there would be things he could never observe, or would everything in the N hemisphere have moved in front of his scope eventually?

I certainly wouldn't say no to a look through it. It was restored a few years ago and a new mirror was constructed, but unfortunately the plan to bring it to working order didn't reach fruition. Reading up on it, it was moveable in azimuth by about 15 degrees.

[swamp thing]

Julian

If you really wanna see the spiral arms of M101 you've gotta go somewhere dark.......period. That's it in a nutshell.

Aperture won't do it alone, trust me on this. From home (here in London) my 20" scope won't show spiral structure at all. I'm lucky to see a tiny faint glow from just the core. Go somewhere dark.......I'm picking out the HII regions in the spiral arms that are filling the entire eyepiece

BTW screening won't do zip either. Without dark skies forget it. A well screened 20" from a dark park in the centre of London won't show spiral structure. Again trust me on this.

It's not about aperture it's about contrast. The ONLY way you get contrast is.......go somewhere dark.

Good luck buddy

[cotterless45]

Dark sky observing is a whole different game. M33 and M101 structure can be seen in a 10" Dob. Edge of town is tough for galaxies, except the brightest,

Nick.

[Mike73]

Screening off your back garden from stray light or getting the council to fit a shade on a nearby street light will help with your dark adaption but as Swampthing mentions that really wont help make faint galaxies visible.

Dont use too much magnification on M101, as you increase the magnification the exit pupil drops and so does the contrast so keep it at medium to low power.

I sketched M101 last week, the sketch makes the arms look very bright and obvious but in truth although I could easily see them they werent as obvious as the sketch suggests but you should be able to see the same with your 12" the only difference will be the image scale.

As long as you have transport then forget about light pollution filters and moaning to your council etc, just put some fuel in your car and get out of town. 

Good luck Julian.

[JulianFR]

Great advice all round. Thanks everyone. Looks plain that dark skies are vital. Luckily there are good dark sites close to me in this part of Wiltshire so I plan to get out there before the light evenings really get long.

[Dreamweaver]

I totally agree that you have to go to a dark sky site. I live in south east London and like everybody else in light polluted skies there is little point in trying looking for the faint stuff. I have not ever looked for M101 but I have seen M51 a few times from dark places.

For comparison. I could just make out, with averted vision, M51 in 10x50 binoculars when in Norway last year (September) on a fjord. I was excited at even being able to locate it!  It was quite low in the sky but pitch black everywhere so it was possible to discern a very faint fuzzy blob with averted vision. That was the first time seeing it through binoculars. There was only one faint tiny blob. Then  a couple of weeks ago I was in Exmoor near to a place called Wheddon Cross. This whole area is a National Park having International dark sky status an YES I could see M51 every clearly through binoculars, however it was quite near to the zenith so this probably made a difference. I was gob-smacked as I could discern two brighter cores! It was still fuzzy through my 80mm Apo but I could make out the two central cores easily enough and what a sight. This place was dark, however it did not appear to be any darker than other places that I have been to but I guess it was. Why else would it have dark sky status? There was limited time to observe as there were heavy clouds and rain rolling in. I have not seen M51 as clear in binoculars anywhere else other than at Exmoor. I have been to various dark places around the south coast but I guess Exmoor is the nearest place to me that has the extra darkness and well worth travelling to get good observing if the weather is favourable. The down side is that it's a four hour drive for me! 

I would seriously consider moving to this area as living in light polluted skies is just so frustrating!

[scarp15]

Observational sketches such as those provided by Mike, provide a good reference for observers, particularly under similar conditions and circumstances, they are also great to look at because they are so energized.