Astronomy with an online telescope
Astronomy with an online telescope

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Astronomy with an online telescope

Week 3: Stellar magnitudes


Last week discussed the importance of waiting for your eyes to dark adapt when you observe the night sky and also the importance of a good observing site for getting the best out of your view. You also saw how using optical equipment such as a pair of binoculars or a telescope to collect more light can greatly add to the number of objects you can see.

This week you will explore how the brightness or (in astronomical terms) the magnitude of an object affects your ability to see it with your eyes, and with binoculars and telescopes. This knowledge will be really useful in planning the imaging that you will undertake next week with COAST as it will help you to determine exposure times and decide which objects to target in order to obtain your own beautiful astronomical images.

Download this video clip.Video player: boc_aot_1_video_week3_intro.mp4
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Welcome to week three. I really hope that your confidence is building now that you've had a chance to use Stellarium, and you've had a chance, I hope, to have a good study of the COAST telescope, as we did last week.
Next week, you'll be taking your first observations with the telescope. So this week, we really want to think about how we build up our observing plans. And think about the different objects that we can see in the night sky and the magnitudes that they have, how bright they are.
Personally, I really enjoy having a look at the Milky Way. It's a fantastic area of the sky to study. And you get a huge range of different objects that become visible to you as you look at it with the naked eye, with binoculars, and with a telescope. So I really hope that you take the opportunity to go and have a look at the Milky Way for yourself, certainly, with the naked eye. But if you've got a pair of binoculars, I really encourage you to get out there and have a good look
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By the end of this week you will be able to:

  • understand the astronomical magnitude scale and how it relates to the brightness of stars as viewed from Earth
  • analyse the magnitude limits of COAST and other instruments
  • discuss the faintest object you can observe with the naked eye.

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