Staying warm:

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Much of the following may seem patronising to those used to cold climates. As with all things you are completely free to ignore my advice. I have decades of experience in walking, climbing, cycling and camping in winter so I have learned the hard way. I started out by making my own mountain jackets and winter sleeping bags out of my old, Terylene wadding, summer, sleeping bags. Prices for serious winter gear were beyond my pocket back then. The downside was the the sheer weight and bulk of my kit and the unbelievable size of my rucksack! Now many sports clothes shops seem to sell high quality down-filled clothing and sleeping bags.

Temperatures are very subjective and only meaningful to the person experiencing the conditions. -3C with a biting wind in the UK is kid's stuff compared with Continental Europe or parts of the USA. That doesn't mean that the UK observer doesn't feel the cold and probably needs advice on dressing appropriately more than any other nationality. It does seem to be a native blind spot. While those blessed with Arctic conditions every year know exactly how to dress properly to match their own conditions.

Many amateur astronomers complain about being cold at the telescope. Yet there is absolutely no reason why they can't be toasty warm down to -10C with very little effort or expense. It's no use going out in a pair of jeans and a denim jacket expecting to be comfortable in cold conditions. Staying warm means you need both both insulation and protection from the wind. Insulation needs lots of thickness to function well by trapping still air. Still air is an excellent insulator. Moving air will chill you faster than much lower temperatures in still air thanks to something called the wind chill factor.

Wind proofing is best when it isn't also completely waterproof. Waterproofing usually means a high risk of condensation on the coated inner surface of the nylon shell if you so much as move a muscle. You aren't likely to be daft enough to try and observe during heavy rain so the idea is to insulate yourself with thick wadding or down within a light windproof shell. The shell is usually damp proofed, very finely woven, nylon cloth. Most down jackets I have come across seem to have a decent enough outer shell without adding another windproof jacket on top. Wearing anything tight or heavy on top of down clothing will compress it. Robbing you of its superb insulating power.

If you smoke you will soon regret wearing "proper" winter clothing. Because sparks from your cigarette or pipe will burn neat holes through the thin cloth like a hot knife through butter. Your precious down will start to leak rapidly through the holes you've made unless you patch them well and immediately. Good luck with that! So if you do smoke you'd better put a light cotton jacket over your expensive nylon shell. Did you know that smoking spoils and slows dark adaptation? Thought not. The flash of a match is unlikely to help you see faint fuzzies either.

Down filling has the advantage of allowing free and easy movement however thick the insulation. It also compresses really well. Down to almost nothing if you need to store or carry it. Thick wadding is often too stiff when you want to lift your arms to reach up to focus or make other adjustments. I won't give a wadding jacket house room any more. It's down every time. Smokers should seriously consider wearing wadding filled clothing to avoid the inevitable down loss from self-inflicted damage.

Down is usually very much lighter than most kinds of wadding and snuggles naturally around you. Being so flexible and compressible one can wear one down jacket inside another if conditions demand it. The advantage here is that even more still air is trapped between the two garments. The necessary seams to keep the down under control and evenly distributed are also very unlikely to overlap. So two thinner and lighter jackets can be as warm as a good single jacket.

The two jackets will be heavier and stiffer than a top quality mountain jacket but still offer superb warmth and flexibility in temperature control. The same goes for a down waistcoat under a down filled jacket. This is a really cosy combination I use a lot of the time. The problem with these superbly insulated clothes is staying cool enough if you exert yourself. Thankfully most observing means standing or sitting around for long periods with stable but comfortable temperatures inside your clothing.

Being a lifelong recycler and now living in a cold winter climate I keep my eye out for good used examples of down clothing in charity shops. I rarely need to pay more than £5-7 ($10-15US? Or equivalent) for superbly warm down filled jackets in clean, as-new condition. Having collected together a great variety of down jackets, insulated trousers and waistcoats I now have a wide choice. I dress depending on outside temperatures, wind strength and my subjective need for warmth. All of which vary widely.

Who cares about the slightly loose fit or the bright colour of the down/duvet jacket I'm wearing when I'm standing completely alone out on the lawn in my pitch dark, rural garden? Do I care that I look like the Michelin Man? No, I don't and nor should you. Dressed appropriately you will actually begin to enjoy the cold crisp nights and cool evenings at the telescope. You will spend more time observing. Instead of staying indoors to commiserate with other people complaining about the cold on the astronomy forums!

Thank goodness duvet jackets are now a common fashion garment thanks to their widespread use in the USA. When I started wearing my first, fat, down, mountain jacket in my youth people would stare at me on the bus. Remember the Back to the Future reference to the "life saver" when the hero was wearing a down waistcoat! A fashion garment in the wrong time period? My jacket was actually so warm that I usually had to take it off to stop myself from sweating buckets before I reached my destination. I was always experimenting with thermal underclothing back then to avoid the chilling effect of sweating indoors then going outdoors into the cold. It is actually far easier to simply take the jacket off indoors then put it back on when it is really needed! You can't argue with simple physics.

Down choice: Look for the vital garment label: Sometimes inside the collar or usually low down in the side the body lining under a sleeve position.

Given a free choice look for pure, thick, goose down rather than duck down of the same thickness. Goose down is warmer than duck for the same thickness. Look for wall quilting. Or double, overlapping quilting. Much better than the cheap sewn-through panels which are cold at the seams you see on cheap, fashion jackets. Look for high percentages of down to feather. Or pure down if you can find it. Feathers are very poor insulators compared with pure down. The feathers can easily be felt through the cloth shell with poor quality fillings. Squeeze the garment between your fingers to check for stiff quills. I wouldn't buy a lumpy filling like this at any price.

Pure goose down is very expensive when new but you should be able to find a good but very affordable jacket if you regularly monitor a number of charity shops in your area. People get fed up with the colour or the style and just give them away to charity shops. Students are fond of them so if you live in a university town you might have more luck in your search. Or more competition for the good stuff!

Older down jackets tend to start losing down from the seams which will cling to your black fleece wear. This may explain the large number of jackets I see in charity shops. Who cares if you look like you've been rolling in the snow as long as you are warm at the telescope? Give a secondhand down jacket a shake to see if it is shedding down badly before you decide that you can't live without it. One or two bits of down floating about is okay. A cloud of down is just not worth the trouble.

Beware that the law in some countries allows quite high percentages of feathers to down to be still called down on the label. Down has the unique ability to expand as it warms from body temperature. The superb insulation of pure down actually grows thicker when worn. Wadding just does what it does and slowly gets thinner from repeated compressions.

A down filled duvet is a superb choice on your bed at home compared with the stiff slab of wadding which falls off onto the floor all night. The down filled duvet wraps itself cosily around you. Closing off those chilling air gaps without weight. The same goes for down sleeping bags.

I managed to tempt my wife out of doors in a light frost to take the posed photograph below. No, I'm not the invisible man wearing a pink rubber glove! I deliberately obscured my face to maintain my privacy. Under all that down gear I'm as slim and as handsome as you are.

If you can't or wont buy at a charity shop and live in an area where there are climbing shops you could check out the down jackets there. Price tends to follow quality and lightness. The absolute best, super quality down fillings, light but incredibly tough shell and the way the filling pockets are arranged inside the jacket walls are inevitably expensive. These jackets have to withstand high altitudes, very low temperatures, very high winds, tearing and abrasion from climbing rock, ice and ice axes, crampons and ropes while allowing complete freedom for the wearer.. Things you hopefully won't concern yourself with on the back lawn. (where you usually have the choice of going back indoors to live another day!)

Compare prices at the climbing/outdoor shops with the rather heavier jackets sold at the high street fashion/sports shops. See if you can manage without the top quality mountain gear which always attracts a premium in price. Your wallet will obviously dictate your choice. Just don't buy anything too tight however rich you are! You need room for lots of clothes (or at least down waistcoat) underneath on the very coldest nights. Nowadays you can shop online but be sure of your sizing or ensure you can return goods which are too tight. A tight down jacket is worthless and will actually self-destruct as the seams are constantly stretched by your movements. You should hardly know you are wearing a good down jacket as it so light, snug, warm and comfortable.

I always wear a floppy Thinsulate (tea cosy) hat while observing because it is light and non-allergenic. It also stays on my head even if bend down to pick something up. Wool hats make me itchy. A soft hat can be adjusted to cover cold ears when it isn't quite cold enough for a balaclava. A lot of heat is lost from the human head in cold conditions. A baseball cap is a real nuisance at the telescope at night. It isn't remotely warm and the peak is always knocking against the finder. If you reverse it, street-cred style, the peak lifts the cap off your head as you tip your head back to look through the eyepiece. Save the baseball cap for solar observation where it offers some shade.

A balaclava is one of the warmest additions to your observing wardrobe in cold, breezy weather. Balaclavas can be pulled down to protect the neck and ears or worn rolled up into a floppy tea cosy. Sometimes I wear mine with the Thinsulate hat as well for extra warmth. Or both under the thick, down-filled hood of one of my duvet jackets if it is really biting cold and windy. Flexibility is the key. If you find yourself getting too warm while carrying your equipment across the garden to a new spot you can quickly remove your headgear for a rapid temperature loss without chilling your body.

Forget all about cold jeans even with thermal longjohns underneath. Fleece jogging trousers (or track suits) are available in many thicknesses and are far warmer. You can wear two pairs if sized appropriately. A slim, snug pair under a baggy pair offers superb warmth and windproofing without limiting your movements.

Then there are the light, wadding-insulated, over-trousers to wear on top of your long fleece pants. I'm not sure if these are intended for hardy golfers but I have accumulated several pairs to swap around depending on conditions on the night. Loose and baggy is best with these and it isn't a fashion parade anyway. They usually have elasticated waists so stay up even when bought deliberately oversized to fit over fleece trousers. Down filled trousers can be very warm but are easily compressed when sitting. Wadding is more resistant to compression and can be bunged in the washing machine without second thought. Down needs far more care in washing.

I have several down waistcoats which are valuable for extra warmth and offer great flexibility in heat control. I can open my jacket if I get too warm and the waistcoat maintains body heat. Or I can open the waistcoat as well to cool off rapidly when necessary. I can keep eyepieces in the waistcoat pockets if conditions are leading to rapid misting. The eyepieces are then rotated through my right jacket or waistcoat pockets. My compact digital camera always sits in the big left hand jacket pocket to avoid internal condensation. Developing habits like this ensure nothing expensive gets broken by dropping several things at once into a deep pocket.

Gloves are a complete pain in the "wotsits" because they deny fine dexterity for tightening those daft little draw tube or star diagonal eyepiece clamping screws! I am usually warm enough to do without gloves because I protect my core temperature properly. A warm body does not draw heat away from the extremities to survive. So your hands and feet usually stay nice and warm. Beware of very cold metal welding itself to the bare skin of your fingers though! A little moisture is the danger here. Plastic focussing knobs are actually far more practical in winter than fancy, expensive metal ones! Rubber sleeves on the focussing knobs no doubt help here but why bother when plastic is so superior? Down jackets usually have large hand warmer pockets anyway once you have the object centred in the field of view.

Hiking boots are better than ordinary shoes and far better than trendy trainers. You need plenty of room for thick winter socks so don't buy boots that are too tight. It's not a fashion parade alone in the pitch dark. Rubber Wellington boots aren't ideal but may be useful in deep snow. I find them too cold.

Staying comfortable is the trick. Get too warm and you'll sweat too easily under all that insulation. Which means it will feel like an ice cold bath when your own sweat suddenly condenses against your skin through your wet vest or t-shirt. If you feel yourself getting too warm you must open up your jacket, take off your hat or lose heat somehow. Don't ignore the first feelings of getting too warm or you will suffer far more than simply being too cold.

Going back indoors to download your camera, or to look at a star map, will cause you to rapidly overheat. Make a habit of taking off the jacket and hat or you'll feel really cold when you go back out again. If you start to feel cold when outside do some exercises in small doses until you feel pleasantly warm but never hot. You must avoid sweating at all costs so your undergarments stay dry and warm.

Keeping the telescope comfortable:

I find anything below about -10C begins to make life difficult at the telescope. Many plastic insulated cables stiffen up in the cold. The slightest breeze rapidly increases the wind chill factor. This is where observatories score highly against standing out on an exposed lawn or yard because they offer shelter from the wind. A dome reduces your own radiation to the night sky and offers the most wind protection. They also have thermal issues from boy heat escaping through the open slit. Just where you are trying to look through with your telescope!

A roll-off is better still and provides shelter from the wind. Even a slight breeze increases the wind chill factor dramatically. If you have a permanent site in the open garden it would be worth putting up a few fence panels and strong posts to shelter you from the prevailing wind. Hedges take too long to grow into a decent shelter belt and are poor windbreaks in winter anyway. I know this because my garden is surrounded by tall trees and tall hedges and it is often still very windy out there.

Cold eyepieces may steam up from the moisture of your eye. Or dew up from your breath if you don't deliberately direct it away. When you are breathing through a balaclava it isn't so easy to keep the eyepiece clear of dew. I pull my balaclava down under my chin and breathe downwards through my mouth to avoid fogging the glass. Keeping eyepieces in a pocket allows your body warmth to keep them far warmer than in an open box or rack. On dewy bights an open rack or box will soon get very wet.

Residual moisture inside the OTA can fog up a refractor objective inside where it can't easily be reached with an electric hair drier. This has ended a couple of my very cold observing sessions in the past. A good long dew shield helps to keep the glass just above the ambient air temperature. Most modern refractors have woefully inadequate dewshields. I'm sure they are styled like this just to make them look short and stubby like the ultra-expensive Apos. (Apochromatic refractors)

Just roll some black, closed cell, camping mattress around the original dewshield to double its length and hold it in place with a bungee, string or even thick rubber bands. The foam will act as an insulator as well as improving your telescope by having a proper light and dew shield. I'm often surprised how my neighbour's security lights will fog the field of view. Even when the telescope is pointing away by quite a large angle. The matt black paint inside the skimpy, Chinese dewshield of my Celestron 6" refractor is obviously not all it should be! Thin, black, closed cell foam from craft shops is good value when used as an anti-reflection surface inside the dewshield . No doubt contrast could be further improved by applying it elsewhere inside the OTA.
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