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Suburban galaxies in binoculars

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#1 revans

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Posted 03 July 2020 - 06:21 PM

I live in a yellow/orange light pollution zone according to the maps.  I'm in a medium sized New England town of about 40,000 people that is part of a tri-city area of maybe about 100,000 people.  I personally haven't noticed much additional light pollution here over what was present in the 1990s.  I can probably nearly see 5th magnitude stars on a "dark night" here with unaided vision and I doubt it was much better in the 1990s.  I was looking at some old observing notes and saw that I had repeatedly found M101, M71 and also the North American Nebula from my yard in 1994 using 4 inch 25x binoculars. Since then I've given those binoculars away to a relative who is a marine biologist and he uses them to spot marine mammals at sea.  But I do have my 80mm 11 x Celestron binoculars.  So far I haven't had any luck finding M101 from my yard this year, but the moon has usually been out when I've looked and has been around first quarter or so.  Is it unlikely that I'll find M101 from an orange zone city with these binoculars or should I persist with trying?



#2 Astroman007

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Posted 03 July 2020 - 06:27 PM

I'd say keep trying. You never know...every night is different. Maybe you'll find yourself with a clear night and a power outage coinciding. :)



#3 eyeoftexas

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Posted 03 July 2020 - 06:33 PM

Definitely try when it's new Moon.  M101 is not very bright.  Try M81 and M82 to see how that goes.  I can see those from my Bortle 7ish skies.



#4 Tony Flanders

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Posted 04 July 2020 - 05:07 AM

I live in a yellow/orange light pollution zone according to the maps.  I'm in a medium sized New England town of about 40,000 people that is part of a tri-city area of maybe about 100,000 people.  I personally haven't noticed much additional light pollution here over what was present in the 1990s.  I can probably nearly see 5th magnitude stars on a "dark night" here with unaided vision and I doubt it was much better in the 1990s.


I am familiar with Fitchburg, but the closest to there that I have actually done astronomy is my astronomy club's field in Westford. At that site, I have no trouble seeing M101 in my image-stabilized 10x30 binoculars, so I'm sure it would be easy in 11x80s. However, it is surely considerably darker than anywhere inside the city limits of Fitchburg.
 
Sadly, saying that you can see 5th-magnitude stars doesn't add much extra information. If the faintest star I can see is magnitude 5.0, I would classify that site as "mediocre suburban" at best. After all, I can see down to magnitude 4.7 in Cambridge.
 
But if I can see stars of magnitude 5.9, then I would classify the site as "excellent suburban," almost bordering on dark. In other words, NELMs in the magnitude-5 range pretty much span the gap between places where deep-sky astronomy is seriously challenging and places where it's really easy.

I agree, by the way, that most places in New England are little if any brighter than they were in the 1990s.
 

I was looking at some old observing notes and saw that I had repeatedly found M101, M71 and also the North American Nebula from my yard in 1994 using 4 inch 25x binoculars. Since then I've given those binoculars away to a relative who is a marine biologist and he uses them to spot marine mammals at sea.  But I do have my 80mm 11 x Celestron binoculars.  So far I haven't had any luck finding M101 from my yard this year, but the moon has usually been out when I've looked and has been around first quarter or so.  Is it unlikely that I'll find M101 from an orange zone city with these binoculars or should I persist with trying?


If I were you, I would keep trying. Though I certainly wouldn't bother unless the transparency was very good (likely not to happen again until late August, when M101 will be getting quite low) and the Moon is absent.




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