Amateur Astronomy

[Miked]

Just out of curiousity, what is the limiting magnitude of all of your skys? (i.e. what is the faintest star that you can see on a clear night with the naked eye?)  There is a lot of light pollution where I live, so the LM is only about a 5-5.5 here.

-Miked

[Hyperspeed]

A friend and I camped on the garage roof one night and we could swear we heard a meteorite as it disintegrated - like a crackling noise. It left an impressive glowing trail that stayed there for a few seconds.

And there was that time we climbed onto the roof to watch the eclipse but it only got to lower light levels. The birds stopped tweeting though which was creepy.

If you pointed one of your telescopes directly at the sun could you make a fantastic, ant-incinerating laser?

[blobrana]

Impressive,
the sound of one meteor crackling.

If you pointed one of your telescopes directly at the sun could you make a fantastic, ant-incinerating laser?

Stand back Ming the merciless...

[Agafaster]

5-5.5 isnt bad, you know ! thats IIRC all the human eye can discern at the best seeing anyway.

I probably get down to about 3 or 4 - though thats a complete and unashamed guess, as I've never really thought about it !

however, last year we had a holiday in Pentewan near Mevagissey,Cornwall - the seeing was absolutely incredible - every clear night, the milky way was absolutely gorgeous !
the camp is right by the beach, so come twilight I took my eldest up there with some binoculars - needless to say she was impressed !

the next clear (hah!) night after we got home, I got so depressed - the orange glow of Wolverhampton to the Northwest, Birmingham to the Southeast, Walsall to the East, and Dudley to the West really p!ssed me off.

[Miked]

the next clear (hah!) night after we got home, I got so depressed - the orange glow of Wolverhampton to the Northwest, Birmingham to the Southeast, Walsall to the East, and Dudley to the West really p!ssed me off.

There is an organization in the USA called IDA (international dark sky association- the website address eludes me but you could probably do a search).  Their mission is to protect the skys from an overabundance of light pollution (unneccessary light pollution).  It is very intriguing.


Miked

[JaXanim]

The British Astronomocal Association also runs the Campaign for Dark Skies (CfDS), whose website can be found HERE.

The British Government is supposedly looking into the issue of light pollution and the effect of aviation on astronomy. It won't achieve anything of course. Tony has more important issues to think about.

The chances are that our great great grandchildren will live their lives without ever seeing the Milky Way.

JaX

[Agafaster]

The chances are that our great great grandchildren will live their lives without ever seeing the Milky Way.

sad but true.

all it takes is the use of a shield on top of street lights to prevent the light escaping upwards - the upshot of this is that a less powerful bulb is required to give the same light levels on the road and path meaning less power is used, and less Carbon is being emitted.

not only is light pollution insidious and ugly, its also very wasteful.

[JaXanim]

A house quite a way away from us has one of those automatic on-at-dusk, off-at-dawn 'security' lights. It has a 360 degree spread and serves no useful purpose whatsoever. It's very intrusive and spoils my view of the stars from my back garden. I'm trying to grow a tree to mask it.

One night last winter we had a power cut and the darkness (and silence) it created was just amazing. Fifteen minutes of bliss as far as I was concerned.

JaX

[blobrana]

Hum,
perhaps you could ask them nicely to make a baffle to stop the light from trespassing in your direction.

And remind them, that a householder (a non-astronomer) in the UK took legal action against a commercial property whose security lights were causing a nuisance - and the householder won the case.

So, there is light at the end of the tunnel...

It appears that the clause (section 102) in the Clean Neighbourhoods & Environment Act 2005 relating to making light pollution a Statutory Nuisance under the Environmental Protection Act 1990 came into force on the 6th April 2006.

http://www.croydonastro.org.uk/lights.htm

http://www.defra.gov.uk/environment/localenv/legislation/cnea/index.htm

Direct link (377kb, PDF)

[Miked]

JaXanim wrote:

One night last winter we had a power cut and the darkness (and silence) it created was just amazing. Fifteen minutes of bliss as far as I was concerned.

JaX

A few years ago in the northeastern United States, there was a massive multiple state blackout.  I have never seen a more beautiful night sky (there wasn't a single photon of light illuminating into the sky)  

-Miked

[Hyperspeed]

by Agafaster:
all it takes is the use of a shield on top of street lights to prevent the light escaping upwards

A lot of cars from Jaguar and BMW are now appearing with head up displays and night vision panels on the windscreens (windshields). This may reduce the need for car headlights and even streetlights in rural areas in the future.

I believe super efficient reflectors and LED technology will reduce the light polution levels, whether this benefit will be undone by more industry taking advantage who knows.

I suppose fog is the main problem on an island like Great Britain. Today for example was warm and it generated high humidity which blocks a clear sky (in the night this mist reflects the light).

Another downside to light pollution is human and animal health. Light triggers the endocrine system and can affect sleep, growth, mental health etc.

[blobrana]

Hum,
A bright supernova anyone?

(mag 12.5)

Web link:

(i could make a joke about the brightness of it, but its a bit too low from my skies to see clearly - but is the brightest one in a few years...)

[Miked]

blobrana wrote:
Hum,
A bright supernova anyone?

(mag 12.5)

Unfortunately, with my 80mm telescope and these light polluted skies, I don't think I'll be able to find that deep sky object  :-(

[blobrana]

Hum,
No,
it a job for a 8" or bigger.

(Don't you find it funny how supernova magnitudes are always  just within the limiting magnitudes of the discovery telescope?)

[Hyperspeed]

by blobrana:
Hum,
No,
it a job for a 8" or bigger.

*giggle*

[blobrana]

My Website feature of the month.
A nice clean and informative astronomy website
www.astronomynz.org.nz

Worth bookmarking.