Light polution any where in the UK

[saturn5]

Mine's remarkably accurate Wigan- about 4.5 limiting mag. Never mind home is where the heart is, I'm moving to Highland Scotland...

Well i've observed at Borgie Forest near Tongue on the north coast of Sutherland which has a limiting magnitude of 7.9 and its amazing just how bright and large the milk way appears,there are plenty of areas within about 5 miles of where i live that are around 7.

Just a shame where i live is about 5.5.Its only a town of 10 000 so i feel sorry for the city dwellers.

[LukeSkywatcher]

Synchronize watches.

[MikeWilson]

There is no substitute for local knowledge.

I'm tempted to make a site that catalogues dark skies... I'm currently making up my own data for nearby potential sites. I've found some very dark (i.e. hand can barely be seen in front of your face) places only a 20 minute drive away. This is good as I, like Astrobaby, have skies so light polluted that you can barely make out stars (only the major constellations, if lucky) at all.

[Buzz Lightyear]

a web 2.0 site would be good where users can update locations where they think are dark or bight on a scale, i have been driving around the country side near my town trying to find the best dark sky spot nearest to my house.

i was surprised by the amount of light polution in wiltshire now, when i was younger things were so different.

going to this spot tonight with my bins to see how much more visisble the stars are compared to my back garden.

[MikeWilson]

Hi Buzz,

I was thinking exactly the same, plus a line of either iPhone, Android or Windows Mobile applications to assist with logging data on sites as well as finding out which is the closest user recommended dark site to you.

I hope you find the stars nicely visible tonight; it's looking like it will be the clearest skies in over a fortnight here so I might go out myself!

[GME]

Now now don't start a nuclear disaster it may glove for an eternity

[darkly]

That's a lot of lights to turn off ...

Spectacular night-time photos of Earth taken from the space station | Mail Online

[spaceboy]

Now Darkly we can't have any mistakes if were gona do this right......... TURN EVERYTHING ON!!! NOT OFF

If all goes well the power stations will be out of action for weeks and we get.......

[darkly]

Now Darkly we can't have any mistakes if were gona do this right......... TURN EVERYTHING ON!!! NOT OFF

If all goes well the power stations will be out of action for weeks and we get.......

And then we can blame the astrologers, some wierd pagan ceremony or something, lets face it, they look as mad as a bag of badgers and would probably enjoy the publicity :D

[smulx]

Has anyone used to map on that website to find a dark site? Just wondering how accurate it is. The nearest black spot to me is the yorkshire moores which I don't really fancy making the trek to.

[SirFoo]

Thanks for links. Very helpful.

[Buzz Lightyear]

Hi,

I found google earth with a LP overlay to be quite accurate for my area, i have recently identified dark areas and gone to them to verify.

a cool feature is to add markers with comments for different spots as you can zoomed in to within a few meters of the area.

AVEX: UK Light pollution Map

and the overlay file can be downloaded from here.

http://avex.org.free.fr/cartes-pl/uk/uk.kmz

Paul.

[Trull]

I've started mapping the NE of Scotland using a Unihedron SQM-L and www.mydarksky.com - check this site for progress!

[Carbon Brush]

Hi. Thanks for telling us of this excellent site.

The 'many stars to nothing' change as you move around is very good. I am awaiting the opportunity to show this to people who can affect LP. That is the county council (street lights) and my MP (making the rules).

Perhaps if other SGL members could show to 'outsiders' it would spread the word?

[bish]

Very interesting. The view it shows you seems quite good. It's amazing how much difference one magnitude can make. I moved from the country, where the limiting magnitude is listed as being 5.2, to Dudley where it seems to be about 4.1. Not much difference as far as figures on paper look but totally different in the actual view.

[Coco]

Thanks Darren... good find

[Photohound]

excellent work - this is very interesting indeed, better start planning my next hols accordingly!!!

[JamesF]

I get an LV figure of 5.5, though I'm surprised it's that low given that the Milky Way is quite visible on clear moonless nights.

OTOH, it's far better than many other people, so I shan't be complaining.

James

[musasi]

although in Spain we do not have this simulator so good

have the same problem

[Trull]

It would be great if more of us observers gave our Naked Eye Limiting Magnitude to www.mydarksky.com - this easily maps the LP and allows people to share dark sites, and if you have a SQL-L from unihedron you can get really accurate. I've put some results up for the Aberdeen area, more to follow.

[MikeWilson]

Is it possible to rent or borrow such a device? I can't see the need to use one for more than a few nights to get an average reading. It might be quite a nice business opportunity for some enterprising individual

[Trull]

I took the initiative to purchase one for Aberdeen Astronomical Society, and this (like all Soc kit) can be borrowed by well established members. I'd like to hope your local AS would do the same. The device cost 150quid from Altair Astro, who would be the people to rent from maybe? Personally I think, renting for two weeks over the new moon would be ideal.

[dogfish]

My wife and I are in the process of buying a holiday cottage in Galloway. Gratified to see that the area gets a LM of 6.8. Slightly darker than Kielder, which'll do me

[parvee]

My location indicates 4.42. And I'm not going to find anywhere below 5 in 50 miles radius. :/

[pete_l]

Before people get too invested in what their theoretical limiting magnitudes are according to someone's map, have a look at the publication:

http://cdsweb.cern.ch/record/327719/files/9706111.pdf

To summarise their findings -

We have shown that the zenith V -band sky brightness at the mid-level of Mauna Kea varies between 21.3 to 21.9 magnitudes per square arc second over the course of a complete sunspot cycle.

Now, how you convert a measured absolute brightness into a subjective value that depends greatly on an individual's eyesight, is a topic for long debate. However a reasonable first approximation (see About Schaefer ) puts 22 magnitudes per arcsecond somewhere between magnitude 6.6 and 7.2

If you take nothing else away from the PDF article, the single most significant piece of information (IMHO) is that the level of darkness varies by over ½ a magnitude depending on the point in the solar cycle. So there is no such thing as a single value for this measurement that we're all so attached do.