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Highlands Astronomical Society

Practical Observing Etiquette

 A guide to enjoying your observing session and getting the most out of it.

Practical astronomy can be great fun, but it can also be extremely challenging. Observations generally take place in the dark when it is cold, and tend to require standing or sitting still for extended periods of time. It’s not as easy as it sounds.

Whether you observe by yourself from your garden or a dark sky site a few miles from your house, or even from an observatory like our Society’s one at Culloden Battlefield, there are several things you can do to make your experience more enjoyable and easier to endure.

  • Wrap Up.  Forget machismo or pandering to fashion. Astronomy can be a very cold business. No, make that VERY cold. Open neck shirts and light jackets will simply not cut it here in the Highlands at the height of the observing season. Temperatures on good observing nights can be well below zero so be prepared and dress sensibly.

What should you wear? Multiple thin layers are best as air is trapped between them and acts as insulation. Thermal underwear (top and bottom) is a good starting point, followed by a couple of layers of comfortable cotton or wool. A warm yet flexible jacket with a good heat retaining material is essential. A jacket with a ‘Thinsulate’ lining (or similar) is very effective at keeping the cold out but will not be too heavy to encumber you. Some observers wear skiwear, which is also ideal, as it too is designed to be lightweight, very warm and flexible. The layers that you put on the main part of your body are important for retaining your body’s core heat, which in turn will help keep your extremities warmer for longer.

A warm hat will stop heat from escaping through your head, and, naturally, warm gloves will be very useful on cold nights too. You may have to take them off to switch eyepieces or do other things that require manual dexterity, but they can always be put back on and will help keep your fingers toasty for when you need them again!

  • Take In Energy.  That means take a flask of hot drink with you. No alcohol, as that will cause your body’s temperature to drop more quickly, but hot tea, coffee or chocolate will give your core temperature that little boost when the cold starts to seep through you. Food-wise, carbohydrate is a great help. Many foods contain carbohydrates, and they break down easily into glucose, which gives our bodies energy – essential for keeping warm and active on cold nights at the eyepiece. A meal containing complex carbohydrates (starchy foods such as rice, pasta, potatoes, chickpeas, bread etc) before venturing out may be enough to keep you going for ages without lagging. If you do start to flag a quick top-up with a source of simple carbohydrates (which break down faster) such as snack bars, chocolate, biscuits, ripe bananas, etc, should bring you back to peak efficiency pretty quickly.
  • Move Around.  Every now and then get up and move around. Flap your arms a little, jog on the spot, whatever, just to get the blood flowing. It doesn’t take a lot. Be careful not to knock the telescope over when you do this, especially if it doesn’t belong to you…

Eventually, despite any or all of these actions, you will get cold and you will get tired. When you do, and there is no way to defeat it, pack up and go home. Mistakes can be very costly so it’s better to know your limits and avoid them if possible. In fact, if you pack up before you get tired, your equipment may well last longer too! It’s not a competition and no one will think badly of you.


Hopefully that covers the physical aspects of enduring an observing session. The next section contains a list of things you can do to make your session enjoyable, rewarding and trouble-free.


  • Prepare.  Preparation is essential to get the most out of your observing session. Think in advance about what telescope and equipment you will need to take and have it ready to take out when you need it so you don’t have to go hunting for it at the last minute. Try and make a list of things you need and get used to having them in a handy place so that you can get them easily. Things like red torches, white torches, paper and pen, spare batteries, tools (if you need them for assembling equipment), eyepieces and accessories, books and charts, etc.

Why two types of torch? Because white light destroys the eye’s sensitivity once it has adapted to the dark. It may take up to half an hour for your eyes to adjust to darkness fully, and a quick flash of white torchlight is enough to put you back to square one. Use white torches for setting up, but then switch to red ones once you want your eyes to adapt and start observing. Also, if you are observing with other people, make sure that you are all using red torches, as it’s even more frustrating when your dark adaptation is destroyed by someone else’s white light.

If you have to take a power supply out to power your equipment, make sure it has enough charge to do what is required of it. If not, you may be forced to end your session early.

  • Sit.  Personally, I find I can see more at the eyepiece when I sit down to observe. It’s more comfortable and the head moves around less, so the eye is held in a better position more easily. A small folding stool is perfectly adequate, though some people will invest in special observing stools that have adjustable seat height settings.
  • Take your time.  Walk, don’t run. Slow down. It’s not a race. If you only manage to fit three objects into two hours, it’s no big deal. Better that than making a silly mistake because you were dashing around trying to do everything at once.
  • Take breaks.  Have a sip of coffee, move around, just look at the sky above you and think about what you’re doing and what you want to do next. Maybe take the time to make some notes about what you’ve seen.
  • Keep a log.  It doesn’t have to be a super detailed essay covering every aspect of your session, but it may help you recall later on what you saw and how you saw it. Making notes can help focus the mind and eye and help you tease out more detail at the eyepiece. The same can be said of sketching from your observations.
  • Interact.  If you hit a problem, ask someone for advice or help. If you are a club member ask one of its experienced observers. If you’re not, consider joining a club, or at least an online forum so that you can get help from experienced people and add your insights too. An awful lot can be learned just by listening to off the cuff comments from people who have spent countless nights out in the cold and dark with a telescope.

Observing Session Etiquette

This section deals with attending observing sessions run by the Highlands Astronomical Society at the Jim Savage-Lowden Observatory.

If you are going to set up a telescope at an observing session, please make the hosts aware of this and arrive early. Arrangements can then be made for a suitable site for the telescope and it should be fully set up before observing begins.

Please use red torches during observing, as mentioned in the section above.

You are welcome to bring flasks of hot drink to observing sessions and they can be consumed within the observatory compound but not within the Observatory Dome or near the computer in the Observing Station.

If you attend one of the Society’s observing sessions and arrive early, please wait until the advertised start time before entering the observatory compound. There is a lot of setting up for the session hosts to do before the event can start and distractions can lead to mistakes.

Please be aware that inside the observatory compound there may well be additional telescopes set up to the sides of the path. Please take care to avoid walking too close to them so as to avoid knocking them out of alignment.

Never touch or handle a telescope without being invited to do so by the telescope’s owner, or in the case of the Society’s own telescopes, one of the session hosts.

Please remember that the observing session supervisors and assistants are there to help you. If you have any questions or problems, feel free to let them know and they will do everything they can to be of assistance.

Entry Fee is a charitable donation of £5 per adult which is greatly appreciated to enable us to operate & maintain our Observatory throughout the Winter season

FREE to HAS & SIGMA Members

Thank you for reading this, and I hope you enjoy your nights under the Highland skies, whether they be with your own telescope, at the Society’s JSL Observatory, or just looking upwards and wondering.

Antony McEwan


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