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May 11, 2022


Unlimited Duration


This course includes:

Unlimited Duration

Badge on Completion

Certificate of completion

Unlimited Duration


This course, Astronomy with an online telescope, shows you how to navigate the night sky, and introduces the wide variety of objects it contains.

You will develop a hands-on understanding of telescopic observations using the Open University’s own robotic telescope facility COAST sited on the island of Tenerife. Supported by your own measurements we illustrate how stars evolve, and study variable stars.

For those new to astronomy and/or the use of robotic telescopes this course provides a practical introduction and will prepare you for further OU study where remotely operable telescopes feature. For those undertaking the GCSE Astronomy course or studying informally the series of structured activities this course contains will allow you to produce a beautiful image of a celestial object of your choice – and analyse the changing magnitude of a variable star over time (one of the approved aided GCSE Astronomy projects).

This OpenLearn science course is produced with the kind support of Dangoor Education , the educational arm of The Exilarch's Foundation.

This course was also developed with the help of the ASTERICS  Horizon2020 project. ASTERICS is a project supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement n. 653477.

Enrolling on the course will give you the opportunity to earn an Open University digital badge. Badges are not accredited by The Open University but they’re a great way to demonstrate your interest in the subject and commitment to your career, and to provide evidence of continuing professional development.

Once you are signed in, you can manage your digital badges online from My OpenLearn. In addition, you can download and print your OpenLearn statement of participation – which also displays your Open University badge.

The Open University would really appreciate a few minutes of your time to tell us about yourself and your expectations for the course before you begin, in our optional start-of-course survey . Once you complete the course we would also value your feedback and suggestions for future improvement, in our optional end-of-course survey . Participation will be completely confidential and we will not pass on your details to others.

This course is endorsed by the CPD Standards Office   . It can be used to provide evidence of continuing professional development but is not accredited learning. We are unable to provide formal learner verification services for participation in our open online courses, which are provided freely by The Open University as self-directed CPD.

Anyone wishing to provide evidence of their enrolment on this course is able to do so by sharing their Activity Record on their OpenLearn Profile, which is available before completion of the course and earning of the Statement of Participation.

Earn this free Open University digital badge if you complete this course! The badge can be displayed, shared and downloaded as a marker of your achievement. The badge is awarded for completing the course and passing the quizzes.

Course learning outcomes

After studying this course, you should be able to:

  • Understand how the apparent motion of the night sky is caused by the rotation of the Earth and the movement of the Earth in its orbit around the Sun
  • Understand how the human eye adapts to dark conditions and how to use dark adapted vision to its best effect when observing the night sky
  • Have an understanding of the different types of telescopes and the advantages of an observatory location at a remote site such as Tenerife
  • Understand how the positions of celestial objects are specified and be able to use this knowledge to predict when a given object will be visible in order to plan observations and make and collect images from the COAST telescope in Tenerife
  • Understand the processes by which stars shine and how they evolve and the causes of variability in stars.

Course Curriculum

  • Introduction and guidance 00:20:00
  • Telescope upgrade 2021 00:15:00
  • What is a badged course? 00:15:00
  • How to get a badge 00:15:00
    • Introduction 00:30:00
    • Finding your way around the sky using Stellarium software 00:15:00
    • Installing Stellarium and getting started 00:15:00
    • Setting your location 00:20:00
    • Controlling how Stellarium displays the sky 00:15:00
    • The apparent motion of objects in the night sky 00:05:00
    • Our changing view of the sky 00:25:00
    • First observations from Tenerife – the All-Sky camera 00:25:00
    • Using Stellarium to understand the apparent motion of the sky 00:25:00
    • Understanding how the sky changes with the seasons 00:25:00
    • Mapping the night sky 00:10:00
    • Two coordinate systems 00:10:00
    • The Altitude-Azimuth system 00:15:00
    • Equatorial celestial coordinates – right ascension and declination 00:30:00
    • Using equatorial coordinates to locate objects 00:25:00
    • This week’s quiz 00:05:00
    • Summary of Week 1 00:10:00
    • Introduction 00:20:00
    • Observing with the naked eye 00:10:00
    • Understanding dark adaptation 00:30:00
    • Testing your own dark adaptation 00:20:00
    • Observing the night sky with dark-adapted eyes 00:25:00
    • Observing with optical instruments 00:10:00
    • Binoculars 00:40:00
    • Telescopes 00:40:00
    • Observing from the Earth 00:20:00
    • The COAST facility 00:20:00
    • This week’s quiz 00:05:00
    • Summary of Week 2 00:10:00
    • Introduction 00:15:00
    • Brightness of the stars 00:10:00
    • The magnitude scale 00:30:00
    • Exploring the magnitude scale 15:00:00
    • Estimating magnitudes by comparing stars 00:30:00
    • Magnitude limits 00:10:00
    • Magnitude limits and choice of observing site 00:15:00
    • Estimating magnitudes from an image 00:25:00
    • Your limits 00:20:00
    • This week’s quiz 00:05:00
    • Summary of Week 3 00:10:00
    • Introduction 00:15:00
    • Messier objects 00:05:00
    • The Messier catalogue 00:20:00
    • The different types of Messier objects 00:20:00
    • Messier objects in Stellarium 00:25:00
    • Requesting your first image 00:03:00
    • Planning your observations 00:25:00
    • Register with COAST 00:10:00
    • Requesting an image from COAST 00:20:00
    • Collecting your first image 00:20:00
    • This week’s quiz 00:05:00
    • Summary of Week 4 00:10:00
    • Introduction 00:15:00
    • Continue observing with COAST 00:10:00
    • The Sun as an ordinary star 00:20:00
    • The Sun – some facts and figures 00:25:00
    • The energy output of the Sun 00:20:00
    • The mass, composition and structure of the Sun 00:20:00
    • The age of the Sun 00:10:00
    • Summary – properties of the Sun 00:10:00
    • What powers the Sun and stars? 00:10:00
    • The most famous equation in the world 00:10:00
    • Nuclear fusion – the source of the Sun’s energy 00:25:00
    • Estimating the Sun’s lifetime 00:20:00
    • Midweek summary 00:10:00
    • Comparing the Sun with other stars 00:20:00
    • This week’s quiz 00:05:00
    • Summary of Week 5 00:10:00
    • Introduction 00:20:00
    • Refine and edit your COAST images 00:20:00
    • Classifying stars – the Hertzsprung-Russell diagram 00:10:00
    • The differing colours of stars 00:25:00
    • Building the HR diagram 00:25:00
    • Understanding the main sequence 00:25:00
    • The masses of stars 00:10:00
    • Measuring the masses of stars 00:25:00
    • How the mass of a star affects its luminosity 00:25:00
    • The lifecycles of stars 00:10:00
    • The main sequence 00:10:00
    • Stellar lifetime as a function of mass 00:20:00
    • After the main sequence 00:15:00
    • This week’s quiz 00:05:00
    • Summary of Week 6 00:10:00
    • Introduction 00:20:00
    • Stellar evolution after the main sequence 00:10:00
    • Helium as a nuclear fuel 00:25:00
    • Expansion and the red giant branch 00:25:00
    • Tracks on the HR diagram 00:20:00
    • The instability strip 00:15:00
    • Variable stars 00:05:00
    • Pulsating variables and their light curves 00:25:00
    • Eclipsing variables 00:15:00
    • Supernovae and cataclysmic variables 00:20:00
    • Collaboration in observing 00:30:00
    • Plan your own variable star observations using COAST 00:25:00
    • This week’s quiz 00:05:00
    • Summary of Week 7 00:10:00
    • Introduction 00:20:00
    • Retrieving your images 00:05:00
    • File formats 00:20:00
    • Save images in FITS format 00:20:00
    • Measuring the brightness of your variable star 00:05:00
    • Aperture photometry 00:25:00
    • Reference stars 00:15:00
    • Using finder charts to identify target and reference stars 00:40:00
    • Aperture photometry 00:30:00
    • Building the light curve 00:07:00
    • View your results on the light curve 00:20:00
    • Interpreting the light curve 00:20:00
    • Request further images 00:07:00
    • This week’s quiz 00:05:00
    • Summary of Week 8 00:15:00
    • Concluding thoughts 00:25:00
    • Tell us what you think 00:05:00

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