The struggle with M 101

[Eastman]

Hello All,

Why is it always so difficult to find M101 unlike other kind of similar magnitude galaxies. I mean the Pin Wheel has a 7.70 magnitude?

But I always seem to have a struggle with it, are there any more of you who share that experience?

Thanks in advanced Gert

 

[Demonperformer]

The magnitude quoted is the integrated  magnitude - the total magnitude of all the bits. But because M101 covers such a vast (relatively) area, the average brightness of it is quite low. This is called the surface brightness and is about 14.4 for M101 - which is very faint for a messier galaxy. Low power can make it easier (you aren't spreading what brightness there is over so great an area).

HTH

[Littleguy80]

I’ve had this same struggle. Darker skies was the answer to seeing it. Here’s the thread I started last year asking a similar question

 

[estwing]

Dark skies are your friend here...best view I ever had was in April 3 years ago at Elan...stunning 

[Eastman]

2 hours ago, Demonperformer said:

the surface brightness and is about 14.4 for M101 - which is very faint for a messier galaxy

Thanks Demonperformer, 14.4 that's makes it a struggle.

 

2 hours ago, Littleguy80 said:

Here’s the thread I started last year asking a similar question

Thanks for sharing the thread on M101 Neil.

[estwing]

..

couple of good reads....gosh it was a heck of a weekend...

[Littleguy80]

Awesome reports, Calvin! What scope were you using? Purple haze from M51! You really hit the jackpot that night!

[estwing]

my 18" Moonshane...did you see the pic along with steves 20"...what a view!

[Littleguy80]

Just went back and saw the pic! Awesome! Had a look through an 18” dob for the first time this week. Amazing and the skies weren’t that good that night!

[timwetherell]

I've been able to see it with a 7" refractor from the UK under 20.5 skies down here in the south west. It's little more than a very faint stain in the sky! One thing that I find helps is to wiggle the scope from side to side. One's peripheral vision is very sensitive to movement so a big dim wiggling thing is a lot more visible than a big dim still thing

[Stu]

The skies are what makes the difference. I’ve seen it in 15x50 binoculars from a dark site before on a lovely transparent night, just a faint glow. In the 16” from Lucksall a few years ago it was fab.

[25585]

Try a UHC filter?

[Stu]

7 hours ago, 25585 said:

Try a UHC filter?

UHC are designed for nebulae not galaxies so in general that’s not a good suggestion....but..... I believe M33 and M101 do have significant HII regions which will benefit from a UHC so worth a try.

[scarp15]

M101 is subtle but not difficult. As repeatedly mentioned, dark and transparent sky, best observed when overhead, permit time to become fully dark adapted, observe at low power. Do not consider observing in light pollution, nor moonlight or with filters. 

[25585]

Wish upon a star. Plenty to choose from ?

[timwetherell]

This was my impression of M101 with a 7" refractor last night under good sky conditions - very much better than my previous viewing where there was a very slight haze and crescent moon. that time it was a barely discernible smudge! M101 does seem to be an object for which sky quality is critically important. I guess back in Messier's day apertures were small but light pollution was non existent!

[NGC 1502]

 

A clubmate and myself bagged M101 two nights ago using our club’s 16” Dob.  First I tried a manual star hop at 70x pointing the Telrad to the right spot that forms a triangle with Alcor/Mizar and Alkaid.

I didn’t notice anything, so tried again. There’s also the starhop along a crooked line of stars from Alcor/Mizar that puts you close to 101.  Then my clubmate used the digital settting circles. Then I noticed that when panning away from where the scope was pointed the sky was darker in all directions. We had found our target but I’d forgotten that it’s a large object that filled the approximately 1 degree field of view, so I’ll keep that in mind on future occasions.

Ed.

[25585]

Star hop using 70x magnification??!!

[ollypenrice]

I never saw it in the UK. Not that one can't but I personally just never did. My first success was in the south of Spain with a cheap 120mm Chinese achromat. The core was actually quite bright and I was amazed. Now that I live under French skies which sometimes hit SQM22 I see it regularly in anything from binos to a 20 inch Dob. But, but, it is about the most fickle object I ever observe. It needs to be really high in the sky, the sky needs to be very dry, and transparency needs to be top class. (Seeing is of little importance). When everything is in place it is enormous but of low surface brightness, as stated by others already. But the spiral structure does come through, as do two bright patches at the opposite ends of two very extended spiral arms.

As I say, it's fickle. I sometimes think, 'Should be easy tonight,' and it turns out not to be!

Olly

[NGC 1502]

7 hours ago, 25585 said:

Star hop using 70x magnification??!!

 

Erm, well sort of, but perhaps when I said ‘star hop’ it’s not the best description. As M101 forms an equilateral triangle with Alcor/Mizar and Alkaid in the Plough’s handle, then I put the central half degree circle on the Telrad on that spot on the sky. But as I said, there’s also a conventional star hop from Alcor/Mizar along a crooked line of stars that takes you close to 101, and it’s possible to do that with a 1 degree field of view. I was using a Panoptic 24mm at 70x for just under a 1 degree field.

Of course, most often, a star hop is done with a very low power to acquire an object before upping the power if necessary for a good view.

HTH, Ed.

[alanjgreen]

As a "galaxy man", M101 & M33 are two of my greatest priorities when it comes to observing... They are always the driving reason for me to buy/upgrade my scope/kit

Here is a sketch of M101 on Friday night in my 20" using military Night Vision & a 55mm Plossl (at only x38 magnification!)

Usually with the ethos10 & 8 (x200-250) I can get the three central "pinwheel" arms. NV added the outer two arm bits. I got fewer internal NGCs with the night vision than I can see with conventional viewing.

Alan

[ollypenrice]

7 hours ago, alanjgreen said:

As a "galaxy man", M101 & M33 are two of my greatest priorities when it comes to observing... They are always the driving reason for me to buy/upgrade my scope/kit

Here is a sketch of M101 on Friday night in my 20" using military Night Vision & a 55mm Plossl (at only x38 magnification!)

Usually with the ethos10 & 8 (x200-250) I can get the three central "pinwheel" arms. NV added the outer two arm bits. I got fewer internal NGCs with the night vision than I can see with conventional viewing.

Alan

Could you tell us about the Night Vision you mention?

Olly

[25585]

M33 can be frustrating to get see much of as well. There it is in the atlas, but where is it in the sky?!

I have seen 33, but now too, will be scouring the sky for 101. Gimme a globular any day!

[alanjgreen]

51 minutes ago, ollypenrice said:

Could you tell us about the Night Vision you mention?

Olly

 

Above are some links to my posts on this subject.

Also see the three observing reports posted so far...

Alan

[ollypenrice]

1 minute ago, alanjgreen said:

 

Above are some links to my posts on this subject.

Also see the three observing reports posted so far...

Alan

Thank you, kind Sir! Much appreciated.

Olly