Astronomy with an online telescope
Astronomy with an online telescope

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Astronomy with an online telescope

Week 3: Stellar magnitudes

Introduction

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
Skip transcript

Transcript

INSTRUCTOR:
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
End transcript
 
Interactive feature not available in single page view (see it in standard view).

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.
AOT_1

Take your learning further371

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses372.

If you are new to university level study, we offer two introductory routes to our qualifications. Find out Where to take your learning next?373 You could either choose to start with an Access courses374or an open box module, which allows you to count your previous learning towards an Open University qualification.

Not ready for University study then browse over 1000 free courses on OpenLearn375 and sign up to our newsletter376 to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371