Observing during winter

[Pryce]

Hey guys!  I've been trying to search around a bit for some more information about observing during winter, and I haven't been able to find much yet.
I live in Norway and winters here can get very rough. Avg. temps varries between -5c and -15c, but the nights can obviously get really colder.

I'm pretty well versed in cold winter clothing and equipment, but I need tips and tricks for the astronomy part.

I've ordered a SW 150P Newtonian with a EQ3-2 mount. I've read that I should take apart any moving parts and regrease them with lithium-based grease since that handles the cold better.  Can anyone provide me guides/youtube videos on how to take apart the apeture and a EQ3-2 mount? And any tips on where I can get good quality grease?

Other than that:
-Are there any limitations on what temperatures I can go out in?

-Are there any precautions I have to take with the equipment before I do take my telescope out in the cold winter.

-I read something abow dew. What temperatures/situations does this occur? Are there any tips on how I can avoid this?  Is it possibly damaging to the equipment?

-I read that I shouldn't go directly from the cold outside to a warm house with the telescope. I live in the city, so I don't have anywhere cold to store it permanently, but would it be enough to transition it into the hallway(usually 5-10c colder than in the apartment) for a few hours before taking it inside? And vice versa before going outside.

[turboscrew]

I'm a beginner myself, but...

At least it's good to check the temperature range of your mount. Also some zoom eyepieces tend to ger really rigid in -20C. The hint is to warm it in your pocket.

The dew, especially when frozen, is a problem, but there are tube warmers (I have heard). I don't remember hearing any other limitations by cold for the optics. I don't think the dew - even frozen - causes damage to your optics, unless there is plenty of it and it melts fast, when you come back in. Probably not much even then - just spots left from evaporated water.

I've also heard that you should dress for -20C as if it was -25C. Standing still a long time makes you feel cold compared to normal outdoors activities.

My 2 cents, and greetings from Nokia, Finland, where it's sometimes about -30C in winter.

[davhei]

After spending a number of nights winter observing in Sweden what made a big difference for me, apart from dew control (home made camping mat dew shield), was hand warmers.

I regularly have to take my gloves off when changing EPs or doing finer stuff and after a while my hands were frozen. The pain when they started thawing later was awful. Putting air activated heater bags in the gloves were a life saver, kept me warm and snug in between taking off the gloves. They stay warm for a good number of hours, enough for my uses anyway. Big difference in how enjoyable the session was.

[Louis D]

Perhaps @jetstream could chime in here.  I believe he observes from Canada which gets quite cold in the winter as well.

[banjaxed]

This is the one I used when I gave my EQ3-2 a strip down and clean, very informative.

[jetstream]

On 13/08/2020 at 19:51, Pryce said:

-Are there any limitations on what temperatures I can go out in?

-Are there any precautions I have to take with the equipment before I do take my telescope out in the cold winter.

-I read something abow dew. What temperatures/situations does this occur? Are there any tips on how I can avoid this?  Is it possibly damaging to the equipment?

I observe down to -40c, with -30c being a common winter temp and the skies in this weather can be stunning.

I refrain from using my refractors in this weather as many issues can arise- cell distortion, dew inside the tube etc.

Newts are very very tough and have no issues in the cold- but- bringing them back inside can cause frost etc. I always put any telescope in a "blanket" or the scope coat the wife made out of an old quilt. My bigger dobs are stored outside.

My AZEQ6 works ok down to -15c but the display starts to go away. My Sky Commander was customized with better display heaters and works well. If observing in -25c and down you might want to consider cold temp grease IMHO.

I live in NW Ontario near the US "Ice Box of the Nation".

[Captain Scarlet]

Also a small piece of camping mat, perhaps 60cm x 30cm, to stand on whilst observing. It's amazing how quickly your feet lose heat through the bottom of your boots, and how much your feet hurt when very cold! I went to watch the World X-Country Ski Championships in Finland in 2004-ish and my cousin suggested that trick. To test it out I tried for a few hours NOT standing on it, and he was right!

Cheers, Magnus

[Pryce]

In the Norwegian army we used something called fotposer, translated to "feetbags" which is cold weather footwear that you just pull over your boots.  
We cut camping mats and put them in the bottom of these before putting them on.  Same function as just standing on the mat, but you're more mobile



 

[scarp15]

Interesting to hear of Scandinavian and Canadian winter insulation solutions. Have a pair of old leather nordic ski touring boots in the loft, they are more beefed up than my four season leather walking boots that I might typically take on a cold winters stargazing outing. 

A repurposed former car rubber boot mat for supporting, insulating the dob from the ground, could be used for standing on, though best when perched on an observer's chair placing feet on the foot rest. 

I will attach a cover over the Telrad in between use and place the fabric caps on the tube, pointed downwards when taking short breaks.

Edited August 22, 2020 by scarp15

[Pryce]

On 22/08/2020 at 23:36, scarp15 said:

Have a pair of old leather nordic ski touring boots in the loft

Remember to coat them in vaseline when you're not using them for long periods or the leather will dry out! Especially if they're old and stored in a loft. 

 

So after your last use of the season,  clean them off with a wet rag,  let them dry and coat them with vaseline before putting them in storage! 

 

If you do that you'll have great shoes for many many maaaany years! 

 

I've had mine for the past 12 years and they're not even showing signs of breaking apart 😆

 

On 22/08/2020 at 23:36, scarp15 said:

A repurposed former car rubber boot mat for supporting, insulating the dob from the ground

Won't that cause too much vibration to be sustainable? 

[Louis D]

On 26/08/2020 at 20:19, Pryce said:

Won't that cause too much vibration to be sustainable?

Quite the opposite for many types of rubber.  It will actually act like a shock absorber and dampen vibrations faster than if the feet were directly on a rigid surface.  The best dampening material is probably still Sorbothane from the 80s.  I use pads of it under each foot of my tripod to dampen vibrations from 3 seconds to 1/2 second.