Assessing light pollution

[ikorodu]

Hello all

Last night I was enjoying a third night in a row with some clears skies. With my job and kids I tend to be out no later than 10:30pm. Given the very light evenings that we have had of late and my relative newbie status I've always assumed that the light pollution in my back garden is pretty bad.

I live in Newark which is a sizeable town of 25000 people and has mostly yellow sodium street lights that are on all night. Last night when packing up I could see more naked eye stars than I ever have before from home. A quick check on stellarium shows that I could pick out stars at mag 5.

Is this considered quite good for an urban setting or is this wishful thinking on my part?

Thanks

Rob

[brantuk]

I could see Andromeda (just) from my drive last night with 3 sodium street lights and the glow from Leicester providing plenty of atmospheric interference. That's a 3.5 magnitude object. I considered myself lucky being about 5 miles from the city center. From Kelling on a clear night in pitch black it really pops out at you along with all the other vast multitude of objects that I ordinarily can't see from here. Hope that gives you a rough feel for it

[SteveNickolls]

Hi Ikorodu,

This site (link below) might prove of interest to you, it contains a night sky simulator using satellite data. Newark is pretty easy to locate Personally I would love to see stars to mag 5 (the limiting sky value is around 4.3 but I do live only 3 miles away from Nottingham). When I travel to friends in Barrowby and others in Bassingham I am always concious of the darker skies out in rural Notts/Lincs. When the Notts County Council street lighting scheme takes effect near you the skies should get even darker-good luck!

http://www.need-less.org.uk/

http://www.nottinghamshire.gov.uk/travelling/roads/road-design-and-maintenance/street-lighting/energy-saving-project/

Cheers,

Steve

[ikorodu]

I did have a quick look for M31, but could not see it. I may have been looking in the wrong place as it was just a quick glance before going indoors. The number of stars around Cygnus was remarkable, by 10:30 it took me a couple of minutes to actually identify the main shape of the constellation there were so many starts up there!

[MarkMayf]

I think that simualtor is a bit on the heavy side. According to that I should hardly be able to see anything, in reality I can easily see 4th magnitude stars, not sure about 5th.

[Mike73]

Ikorodu

LP simulators are handy for rough guides but in reality not that accurate. Download and print off this which will give you a better idea of your actual NELM is and will take seeing conditions into consideration aswell.

I live on the outskirts of a 25000 town and my LM is around 5.2, if I drive just 15 miles out it goes upto LM 6.3 so the best way to see more isnt always aperture, its diesel/petrol!

[ikorodu]

Hi Ikorodu,

This site (link below) might prove of interest to you, it contains a night sky simulator using satellite data. Newark is pretty easy to locate Personally I would love to see stars to mag 5 (the limiting sky value is around 4.3 but I do live only 3 miles away from Nottingham). When I travel to friends in Barrowby and others in Bassingham I am always concious of the darker skies out in rural Notts/Lincs. When the Notts County Council street lighting scheme takes effect near you the skies should get even darker-good luck!

http://www.need-less.org.uk/

http://www.nottingha...saving-project/

Cheers,

Steve

Thanks for the links Steve. The needless site says the limiting mag should be 4.7 so I was doing well last night to see mag 5!

I think some of my good views are due to the neighbor we back on to being on holiday. Whilst they don't have any nasty security lights anyway, I think even the lights through the curtains not being there are making a difference.

Here's to more clear and dark skies!

Rob

[cantab]

Somewhere about 4 for me, I can't see anything besides Polaris and the guards in Ursa Minor, and Thuban in Draco is difficult. I probably lose a bit due to my own vision though, my eyesight's good enough for driving but it's not perfect.

[ikorodu]

I may have a look at Ursa Minor to night to try to get more accurate idea of the NELM. Thanks for all the quick replies.

[bigrbuk]

limiting magnitude of 4.33 according to need-less site, or an 8 on the bortle scale.

Gonna need to find some darker skies!

[ikorodu]

I may have a look at Ursa Minor to night to try to get more accurate idea of the NELM. Thanks for all the quick replies.

Well my viewing tonight confirmed that I can just make out the mag 5 stars in ursa minor. The orange lp sky glow is evident up to the level that m31 is hence I can not see the galaxy with the naked eye.

I used my 70mm travelscope and my 15x70 bins for some quick views tonight. The travelscope needs a mount that's better than my photo tripod and the pants one that it comes with, I might try to mount it on the Meade ds2000 mount I have.

Anyway the andromeda galaxy looked great in the bins as did the double cluster. The whole of Cygnus was awash with stars.

Rob

[Pete Presland]

i live in biggleswade, around 1 mile from the ridiculously illuminated A1(m) and it was pretty grim last to be honest.

[crashtestdummy]

motoways are ridiculous these days,theres no need to have lights every 10m when most of the roads are straight and cars have headlights.

says my limiting mag is about 4.5,i can make out all the stars in orion with the naked eye though

[Mike73]

I had a nice suprise last night, my back garden is usually around LM 5.2 but for some reason all the street lights on my estate were off last night which bumped the LM up to 5.5! Just wish that happened more often!