Pollution

[Little Isadore]

How difficult should it be to see ursa minor with the naked eye? As yet i have not been able to make it out. I am pretty sure that i was able to see it when we were taught (alittlebit) about astronomy at school. Is this due to increased pollution or is my memory playing tricks?

ken

[Talitha]

My sky is pretty dark and allows me to see all of the stars in UMi, except when the transparency is bad and there's a lot of lunar interference... then I have trouble picking out anything except Polaris and Kochab.

That 'sky-bleaching' effect simulates LP to a certain degree, but I'm sure it's mild compared to what many of you experience on a daily basis.

[The Warthog]

Ursa Major is pretty low to the horizon at present, in the early parts of the evening, and gets lower as the evening draws on. If you look up in the northeast, you should be able to see Cassiopeia clearly. Sometimes, due to both air and light pollution, I cannot see all the stars in Cassiopeia, but if U. Major is well placed and free of cloud, I can always see all the major stars in it. My skies are, at best, 3.5mag.

I'm sorry, I read 'major' for 'minor' in your post. In my skies I can see only the two stars in the end of the Little Dipper.

[asteria]

Hi - I went out at about 3:30AM last night and the sky was astonishingly clear. I could see all the UMi stars for the first time. Extraordinary. Usually it's just Polaris (alpha UMi) and the the two other brightest ones, the so-called Guardians of the Pole. These are beta UMi and gamma UMi. Last night it was possible to see the whole chain up to Polaris, the Pole Star. And this was with a very bright Moon.

Usually with the light pollution it is impossible to see all but beta and gamma and Polaris with the naked eye.

Ed

[James]

The four stars at the end of Ursa Minor (the end away from Polaris) are 2nd, 3rd, 4th and 5th magnitude respectively. From Taunton with clear (non hazy) skies I can usually see all bar the 5th magnitude one but the slightest haze etc leaves me able to see only the 2nd and 3rd mag one.

In the five years I've been living in Taunton it has become markedly harder to see Ursa Minor...

James

[Little Isadore]

Thanks all. I was getting a bit worried as i thought it should be easy to see and as i live smack dab in the middle in one of Britain's biggest urban conurbations i thought that if i could not see all of U. Minor i might have serious problems with deep sky objects. So my memory was playing tricks.

ken

[rusirius]

I can see all the stars of UMi on a clear night from my rural location, but as a child I used to be able to see them from within the city of Leicester boundary. Nowdays that is extremely unlikely. Of course, young people have the advantage of having a wider pupil (7mm) when their eyes are dark adapted. As you get older they don't open quite so wide (at middle age mine are probably 6mm) so your night vision is not quite as sensitive, although nothing to worry about. However, Tyneside is a large buit up area (much bigger than Leicester) so I woud imagine that such a large amount of background light would probably make it very difficult to see UMi. Your best bet might be to find a dark site away from '{one of} Britain's bigest urban conurbation{s}.

Another challenge I was taught about at school was to see how many stars you could make out in the Pleiades. The average is 7 (hence the name 'Seven Sisters' but many people can see more. If your eyesight is exceptional (and transparency permits it) you might see as many as 11 or 12! Also more recently I heard about the Roman army eye test. Have a look at the middle star in the 'handle' in the 'saucepan' of the Ursa Major. Can you see one star or two? If you can see 2 then congratulations. You qualify to join! The second star is magnitude 4 though so if you can't see the UMi I'm not sure that you will see two stars except through binoculars maybe.

[Little Isadore]

Thanks risiurus,

I will try that when the sky allows. I said "one of" the biggest i would much rather it was the smallest, believe me.ken

"urban conurbations"? Well that's what big places are called in Wikipedia, you divin't think a daft Geordie like me uses words like that every day do you?