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What would you expect ?

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#1 Voyager 3

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Posted 18 September 2020 - 05:55 AM

I'm in a Bortle 8 , and have 2-3 streetlights within 50m ☹️. So from this site what would you expect to see ? On one superb clear night I just managed to pick the keystone. I could see the northern cross which should be a shame to share . So it's 3.9 at best . Will you expect GALAXY hunting with these conditions and a 8" dob ? I tried M81 , M82 while starting out and did see but I wasn't sure I've seen it . Now how high should my hopes be ?

EDIT : Sry mods pls change to the appropriate forum if this isn't

Edited by Voyager 3, 18 September 2020 - 05:56 AM.


#2 Asbytec

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Posted 18 September 2020 - 06:12 AM

I'd expect lunar, planetary, and some double star observing. Maybe some brighter globulars.

 

What kind of street lights? If not LED, you might be able to filter some of it out and do some brighter planetary nebulae and other emission nebulae. 

 

Me? I'd rule out deep sky such as galaxies and reflection nebulae. But, one huge caveat. I've never bothered with deep sky under bright city lights, so I do not really know. But that is the reason. Find a good dark sky site for deep sky observing. A tank of gas is better...


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#3 jiblet65

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Posted 18 September 2020 - 06:23 AM

I'd expect you need a light pollution filter for your EP's. grin.gif



#4 Tony Flanders

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Posted 18 September 2020 - 07:50 AM

I'm in a Bortle 8 , and have 2-3 streetlights within 50m ☹️. So from this site what would you expect to see ? On one superb clear night I just managed to pick the keystone. I could see the northern cross which should be a shame to share . So it's 3.9 at best . Will you expect GALAXY hunting with these conditions and a 8" dob ? I tried M81 , M82 while starting out and did see but I wasn't sure I've seen it . Now how high should my hopes be ?


At a site where I can see magnitude-3.9 stars with my unaided eyes, I can also see M81, M82, and a number of the other brightest galaxies with an 8-inch telescope. If you can contrive some way to block your direct view of those 2 or 3 streetlights, you might be able to do significantly better.
 
Having said that, it would obviously be worthwhile to travel to a darker site if possible. Although it's possible to detect galaxies in your conditions, it's not possible to see significant detail in most of them. Besides, everything is easier and more enjoyable when it's darker.


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#5 rhetfield

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Posted 18 September 2020 - 09:00 AM

I am in Bortle 7 with a 5".  The first challenge is to see if you can see Andromeda.  If you can't see that (in my skies I only get the core) you won't see any of the others.  For me M81 is hit or miss.  It is there on a good night, but often not there.  M82 is harder for me than M81.  Very rare to see it from my drive.  Lately the forest fire smoke that has now made it to the east coast has blotted out most everything.  Keep an eye out for that sort of seasonal thing around you also.

 

As others have pointed out, if you can get to a darker area - even a bortle 5 - it will make a big difference.



#6 Asbytec

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Posted 18 September 2020 - 09:58 AM

If you can contrive some way to block your direct view of those 2 or 3 streetlights, you might be able to do significantly better.
 

I agree with that based on slightly darker skies I've observed from  with some amount of direct lighting. Create a dark spot you can observe from. It should not do anything to improve the skies overhead, but it does seem to help. Probably by maintaining some dark adaption.

 

I was fortunate enough to totally close off the driveway to my town house with opaque tarps and create my own personal dark spot to observe from. I felt the need to explain to the neighbors why all the "secrecy", but they understood. Put up a sign "Amateur Astronomer Lives Here, No Worries". :)



#7 desertstars

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Posted 18 September 2020 - 10:27 AM

I'd expect lunar, planetary, and some double star observing. Maybe some brighter globulars.

 

What kind of street lights? If not LED, you might be able to filter some of it out and do some brighter planetary nebulae and other emission nebulae. 

 

Me? I'd rule out deep sky such as galaxies and reflection nebulae. But, one huge caveat. I've never bothered with deep sky under bright city lights, so I do not really know. But that is the reason. Find a good dark sky site for deep sky observing. A tank of gas is better...

I've long since adopted such a divide-and-conquer approach. Lunar, planetary, and double star observing keeps me going between dark sky expeditions. I also have very good luck with brighter open star clusters.

 

There are quite a few galaxies and nebulae I can see pretty well in my Tucson skies, but they are so much better away from town that I wait for such an opportunity, and then make such objects the point of the trip.


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#8 epee

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Posted 18 September 2020 - 04:46 PM

Spend home time with stars, Moon and Planets, the Orion Nebula, and bight Globulars. Find a nice dark site within easy travel distance from home.



#9 Andrekp

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Posted 18 September 2020 - 04:51 PM

I live in such skies.  You don’t know until you try.  You will find you can see a lot more than people here will tell you.  Finding things can be more difficult.


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#10 Voyager 3

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Posted 19 September 2020 - 05:36 AM

At a site where I can see magnitude-3.9 stars with my unaided eyes, I can also see M81, M82, and a number of the other brightest galaxies with an 8-inch telescope. If you can contrive some way to block your direct view of those 2 or 3 streetlights, you might be able to do significantly better.

Having said that, it would obviously be worthwhile to travel to a darker site if possible. Although it's possible to detect galaxies in your conditions, it's not possible to see significant detail in most of them. Besides, everything is easier and more enjoyable when it's darker.

The streetlight nearest to me isn't that much off a problem as my house blocks it if I set my telescope at that location . My main problem is the highway . It stretches my full southern side so I couldn't even get my eyes dark adapted . If I just take my eyes out of my scope my adaptation would be gone. But there's a bortle 2 within an hour's drive ( my town isn't a metropolitan , so it isn't spread out but concentrated where I live ) . But my town has been ferociously changing to LEDs in the past 5 years , so I feel filters wouldn't give me the contrast I expect.


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