How cold is too cold

[brascoe]

I was wondering with the autumn and winter coming how cold is too cold for a telescope ?

[Smeg]

-25 (centigrade) is normal for me in winter. (some other places can get colder )

Just don't lick the scope.

[Stephen]

I was wondering with the autumn and winter coming how cold is too cold for a telescope ?

I believe it would have to kill you first before it became too cold for the scope (Celestron actually state they don't have a limitation on it.)

[Darkstomper]

Great question and reassuring answers! Merci..

[Smeg]

Well the Hubble sits in -273 oC in space no?

If anything your grease will freeze second ( you first )

Again humidity would be a factor...

[stolenfeather]

I am situated in the extreme north. There have been nights when I was outside at -45. The telescope was fine but I did have to let it acclimate before using it (a good 20 minutes) to prevent condensation. However, my telescope does not have any computerized parts since it is a Dob. At extreme temperatures, I wouldn't trust my camera or anything with moving parts.

Myself? There has been many nights where I had frostbite!

Isabelle

[Smeg]

Just lock the mirror up on a SLR if its possible.

[lukebl]

....Just don't lick the scope.

Darn. That's put paid to one of my fetishes!

[brascoe]

-25 (centigrade) is normal for me in winter. (some other places can get colder ) blumming hell thats cold dont even think my freezers that cold lol

Just don't lick the scope.

lol sounds like something out of dumb and dumber

[Smeg]

It's not cold, its a dry cold, best kind of cold, low humidity lol

[Moonshane]

in extreme cold I'd imagine you need to be careful about your face sticking to the eyepiece / OTA?

[Pete Presland]

I am situated in the extreme north. There have been nights when I was outside at -45.

Isabelle

that's proper hardcore observing

[DarkV0!D]

Telescope should be fine. What you should be worrying about is yourself. Dress warmly and in layers.

[stolenfeather]

that's proper hardcore observing

I like to call it extreme astronomy!

Isabelle

[garethmob]

lol as isabelle said for visual observing i would imagine its how ever cold you your self can handle iv taken mine out in the show xmas time last year and it was fine just need to make sure if ur gonna do in n out just leave the scope out there as condensation does set, and when u bring it in have some news paper under it as it does become soaking

for anything electric i would say... look in the instructions for its lowest temperature, as the colder things get they contract and it can damage it if u bring it back in straight away (i always leave everything in the conservatory over night after i finished so it can dry naturally but theres not a sudden influx of heat.

[hemihaggis]

so smeg , where abouts are you ?

[MjrTom]

in extreme cold I'd imagine you need to be careful about your face sticking to the eyepiece / OTA?

This would be of concern to me!

I have been out imaging in -20c last year but that was wrapped up in skiware with gloves on and kept the cold metalwork away from bare skin.

Don't go holding cold metal tools like Allen keys and such in your mouth either... Ouch!

I would suspect that condensation from your breath would be an issue too coating things in dew.

[Moonshane]

definitely Mark

someone mentioned that one season it was so cold they were shocked when they went into the house and noticed in the mirror that they had blood running down their face - their eyelid had stuck to the eyepiece slightly and started bleeding.

[yeti monster]

Colder than this:

[MjrTom]

That's dedication!

[JamesF]

I am situated in the extreme north. There have been nights when I was outside at -45.

It's interesting that you put it that way, Isabelle. It made me think about how people perceive where they live in the world.

I'm not particularly familiar with James Bay, but looking at google earth you'll be no more than 55 degrees north, I'd guess? I bet many Scottish SGL members are further north than that and quite a few of them might not think of themselves as living in "the extreme north". The UK just has the benefit of a climate moderated by warm air dragged up from the mid-Altlantic, I guess. I certainly don't fancy being outside at -45F myself.

Perhaps it's because of our climate that many people in the UK don't realise just how far north the country is (until not so long ago I'd have been one of those people myself). James Bay is an interesting example in that it appears to occupy pretty much the same latitudes as England. I'm well to the south, but I've read that the entire Hudson Bay and it's associated waterways can freeze over in the winter. There'd probably be widespread panic if that sort of thing happened here.

Is this a peculiarly British thing, or do you visualise yourself as being far to the north of us because we have a milder climate?

James

[garethmob]

at least at thoese temps one dosent have to worry about the CCDs being too hot:P

[Smeg]

Thought you meant -45 oC.

Thats cold.

Boiling water freezes before it hits the ground That would be Arctic Circle cold.

[MjrTom]

That's very true and agree with you.

We do get a taster from time to time when the gulf steam currents are disrupted and we get northerly winds travelling down from the arctic and Scandinavia. Over the last few winters the mercury has dropped below -20c on many occasions.

[JamesF]

I've happily gone out skiing when the temperature was -14C, but at least then I was doing physical activity that kept me warm. Once dew starts to freeze on the OTA then I do start to wonder if there might be more comfortable ways to spend my evenings.

James