Jump to content


Photo

Which number on the scale best correlates with

  • Please log in to reply
55 replies to this topic

#1 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 08:40 AM

http://stellarium.or...0.10-bortle.jpg

your darkness conditions, and what can you see? To standardize things let's say under good, but not exceptional conditions. Although my wife disagrees, we're definitely about a 7 here, and that's under good conditions. I can make out the big dipper, the constellation Orion (I can see that Betelgeuse is definitely red, mistook it at first for mars being far away lol) and Cancer. There's probably more I can see but no telescope or binonculars and still trying to learn the constellations under trying light conditions.

You don't have to necessarily address my post here, but I think it would be fun for members to post their number, maybe scope size, and some of the notable objects they can see just for fun.

#2 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 09 October 2013 - 08:49 AM

Bortle 9.

obin :bangbangbang:

#3 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 09:00 AM

Does the emoticon mean you can't see anything....? :)

Anyway, at least in TX you can't be too far away from a dark sky. It doesn't get any better than 3 in the whole country here, and that would be hours from me.

#4 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 09 October 2013 - 09:09 AM

The light pollution from the baseball parks, sports fields, plazas, and car dealerships is so bad that I can barely see the core of M31! The only salvation is when I get the gear out at 5 AM. The baseball parks and sports fields turn their lights off and I can see a tiny bit more.

Most constellations are completely missing several stars with the naked eye. I can't wait until a hurricane kills the power around here for a week or two. I think that only then will people realize just how much light pollution there is.

I have semi-dark skies about 20 minutes away and fairly dark skies an hour away. Other than that our Bortle 9 skies can ONLY be explored with astrophotography.

obin :mad:

#5 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 09:53 AM

Might be worth a longer commute in the future, maybe. What's your personal sense of satisfaction when you're out in a fairly clear 9 sky? That's its worth it overall...?

#6 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 09 October 2013 - 10:23 AM

Certainly! You just have to shift your interest into satellites, double stars, planets, clusters, and brighter nebula. After seeing something like TOPEX/Poseidon, a bright ISS pass, Saturn, Jupiter, or even the Orion Nebula it's well worth it though.

obin :)

#7 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 10:36 AM

If I am able to distinguish the bands on Jupiter, the rings on saturn, some of the sattelites, find some nebulae and star clusters, and be able to split some doubles which will show their color difference right into my eye I think I'd be happy.

#8 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11133
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 09 October 2013 - 12:06 PM

If I am able to distinguish the bands on Jupiter, the rings on saturn, some of the sattelites, find some nebulae and star clusters, and be able to split some doubles which will show their color difference right into my eye I think I'd be happy.


Aside from nebulae -- and to a lesser degree star clusters -- all of those are every bit as easy in a bright city as in the most remote rural location.

#9 wargrafix

wargrafix

    Ranger 4

  • -----
  • Posts: 388
  • Joined: 10 Apr 2013
  • Loc: Trinidad

Posted 09 October 2013 - 01:28 PM

This may seem like a voice of discontentment, but its a sad state of affairs when we begin to settle for less and less and even less. I live is not so good skies and its very frustrating. I am trying to see if I can improve things where I am but its a rough uphill battle. Everyone afraid of the dark.

#10 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 09 October 2013 - 01:32 PM

If I am able to distinguish the bands on Jupiter, the rings on saturn, some of the sattelites, find some nebulae and star clusters, and be able to split some doubles which will show their color difference right into my eye I think I'd be happy.


You should be able to without a problem. With an 80mm apo refractor and a 9mm eyepiece I can clearly split doubles and see color differences even from my front yard (which is far more light polluted than the back yard).

obin :jump:

#11 BrooksObs

BrooksObs

    Viking 1

  • -----
  • Posts: 787
  • Joined: 08 Dec 2012

Posted 09 October 2013 - 01:45 PM

Currently, a 4 bordering on a 5.

20 years ago a 3.

40 years ago 1-2 and at 50+ years it must have been a solid 1 here...all at the very same location! Yet, I'm regarded as lucky by many!

BrooksObs

#12 richard7

richard7

    Not Quite

  • *****
  • Moderators
  • Posts: 5860
  • Joined: 02 Nov 2007
  • Loc: Sacramento

Posted 09 October 2013 - 03:18 PM

On an average night, 7.
On a rare, very good night, 5.

#13 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 07:03 PM

To the person who posted earlier, I wouldn't say I'm satisfied at all, but personally considering I live in a metro area of 20 million or so I'm thankful for what I can see. Just a five mile ride towards the center of the city would let me see only a few dozen stars under good conditions. Under bad conditions people there can only see objects less than magnitude 1.

#14 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 09 October 2013 - 07:04 PM

Would those of you who replied mind stating what are some favored objects that you are able to see from your mostly mediocre conditions :)

#15 wargrafix

wargrafix

    Ranger 4

  • -----
  • Posts: 388
  • Joined: 10 Apr 2013
  • Loc: Trinidad

Posted 10 October 2013 - 09:02 AM

you know things are bad when a local power blackout makes things from 9 to just 8.

#16 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 10 October 2013 - 10:12 AM

Ouch, well its definitely a 9 here most of the summer if not worse because of air pollution, as I'm doing more naked eye observations, I'm also realizing it's at least partly cloudy a lot more nights than I realized. You don't think much about a partly cloudy night when you aren't observing...

#17 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 13 October 2013 - 10:57 AM

Well let's see hear I'd like to finish this off by comparing the amount of stars we can cover with one hand, naturally in theory only. My hand's on the small side and if I hold it up high it will end blocking on average 5 stars. I heard Betelgeuse is *BLEEP* about this so be careful around him.

#18 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11133
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 13 October 2013 - 11:40 AM

Well let's see hear I'd like to finish this off by comparing the amount of stars we can cover with one hand, naturally in theory only. My hand's on the small side and if I hold it up high it will end blocking on average 5 stars. I heard Betelgeuse is *BLEEP* about this so be careful around him.


That's too vague; the star density varies immensely from one part of the sky to another. At a typical suburban location it could easily vary from 20 in and around Orion to zero in parts of Aquarius.

#19 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 14 October 2013 - 11:27 AM

Well you're right about that, especially when you have a washed out horizon to boot. Don't have twenty in any part of the sky here tho. But yes even straight up I can see a variance. I'm working on talking my wife into us moving to one of the few green zones in the country, she seems suprisingly receptive so far but we'll see how long that lasts :)

#20 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 14 October 2013 - 10:24 PM

Just for sake of discussion I just went outside 5 minutes ago and counted all the stars visible from my backyard with the naked eye. Mind you I only gave myself about two minutes to acclimate to the darkness. Also the moon is quite full but not totally full. In any case I counted every star I could see. The grand total: 27. Yep. I can only see 27 stars with the naked eye. You guys that live in areas with less light pollution don't know just how good you have it. I remember looking up at a full moon sky and seeing countless hundreds of stars still visible. Not here.

obin :bangbangbang:

#21 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 14 October 2013 - 10:39 PM

Well last night I looked up and I couldn't see any. So there :) Of course it was cloudy...

Seriously though what time was this? I have to do a test when the weather clears out, but I suspect with the moon out around 8/9 pm I might get similar results. 11pm is when things start getting a lot better.

#22 obin robinson

obin robinson

    Mercury-Atlas

  • *****
  • Posts: 2623
  • Joined: 25 Oct 2012
  • Loc: League City, TX

Posted 15 October 2013 - 05:15 AM

This was at about 9:30PM local time. It is cloudy now and the mornings are better because many lights which stay on until midnight are finally off. In the morning I estimate that I can see a hundred or so stars with the naked eye.

obin

#23 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11133
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 15 October 2013 - 07:53 AM

http://stellarium.or...0.10-bortle.jpg

your darkness conditions, and what can you see?


It's a little hard to say. I don't find that Stellarium site helpful at all. But going by John Bortle's original criteria, I would have to classify the skies of my local urban park in Cambridge, MA, as Class 8 on a typical night of good transparency -- which is fairly common here in New England except in the summer.

It correlates pretty well: My limiting magnitude is a bit better than 4.5; I can see M31 and M44 naked-eye, but only with considerable effort, and many of the stars making up the traditional constellations are missing, especially low in the sky.

However, all of the Messier objects are detectable through my 7-inch scope, which is certainly modest by modern standards. And many of them are quite pleasing -- though that's bound to be a subjective judgment.

By the way, this is 4.5 miles from the center of Boston, a metropolis of several million people.

My country home (halfway between Albany, NY and Pittsfield, MA) is harder to classify. It meets most of the criteria for Bortle Class 4. But the zodiacal light is pretty hard to detect, because it just happens that Albany is to the west and Pittsfield is to the east, and those are the directions where the zodiacal light is strongest.

If the dominant light sources were north and south rather than east and west, but the level of light pollution overall was the same, then the zodiacal light would be easy to see, but the southern Milky Way would be much harder to see. On the whole, I think I have the better deal!

The worst location where I have done much time stargazing is Manhattan, which is a good match for Class 9 in most ways. Limiting magnitude just about 4.0, only the Pleiades readily visible naked-eye. (This assumes being on a balcony or in a park where there are few or no lights shining in my eyes.)

However, most of the Messier objects are still visible through modest-sized telescopes, and several of them aside from open clusters are quite attractive. That list is headed by, but not restricted to, the Orion Nebula.

Judging by posts on Cloudy Nights, the biggest problem for most American stargazers is direct glare from nearby lights rather than skyglow. The Bortle Scale is really couched in terms of skyglow, so it's not necessarily applicable in a typical suburban backyard.

#24 AcesDJD

AcesDJD

    Explorer 1

  • -----
  • Posts: 69
  • Joined: 06 Oct 2013

Posted 15 October 2013 - 08:36 AM

Obin, I think our conditions are similar. I think I'm going to look at living in a white zone as a challenge rather than focus on the negative side too much.

#25 Tony Flanders

Tony Flanders

    Voyager 1

  • *****
  • Posts: 11133
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 15 October 2013 - 08:45 AM

This was at about 9:30PM local time. It is cloudy now and the mornings are better because many lights which stay on until midnight are finally off. In the morning I estimate that I can see a hundred or so stars with the naked eye.


It's also because of the sky itself. During evenings in autumn, the southern sky is filled with faint constellations; the only really bright stars are Fomalhaut and Deneb Kaitos.

Before dawn you're seeing the winter sky, which is by far the brightest sector, including the brightest constellation (Orion) and the brightest star besides the Sun (Sirius).

What fraction of the sky can you see, and do you have lights shining directly into your backyard? Those are more likely to limit the number of visible stars than skyglow is.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics