Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgements
- 1 Watchers of the skies
- 2 Our Sun
- 3 Aspects of our Solar System
- 4 The rocky planets
- 5 The hunt for Planet X
- 6 Voyages to the outer planets
- 7 Harbingers of doom
- 8 Impact!
- 9 Four hundred years of the telescope
- 10 The family of stars
- 11 Aging stars
- 12 The search for other worlds
- 13 Are we alone? The search for life beyond the Earth
- 14 Our island Universe
- 15 Wonders of the southern sky
- 16 Proving Einstein right
- 17 Black holes: no need to be afraid
- 18 It’s about time
- 19 Hubble’s heritage: the astronomer and the telescope that honours his name
- 20 The violent Universe
- 21 The invisible Universe: dark matter and dark energy
- 22 The afterglow of creation
- 23 To infinity and beyond: a view of the cosmos
- Index
- Plate section
- References
10 - The family of stars
Published online by Cambridge University Press: 05 October 2014
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgements
- 1 Watchers of the skies
- 2 Our Sun
- 3 Aspects of our Solar System
- 4 The rocky planets
- 5 The hunt for Planet X
- 6 Voyages to the outer planets
- 7 Harbingers of doom
- 8 Impact!
- 9 Four hundred years of the telescope
- 10 The family of stars
- 11 Aging stars
- 12 The search for other worlds
- 13 Are we alone? The search for life beyond the Earth
- 14 Our island Universe
- 15 Wonders of the southern sky
- 16 Proving Einstein right
- 17 Black holes: no need to be afraid
- 18 It’s about time
- 19 Hubble’s heritage: the astronomer and the telescope that honours his name
- 20 The violent Universe
- 21 The invisible Universe: dark matter and dark energy
- 22 The afterglow of creation
- 23 To infinity and beyond: a view of the cosmos
- Index
- Plate section
- References
Summary
Virtually all of the light that we can see in the heavens has come from the surface of stars and they are, certainly for our existence, the most important objects in the Universe. The heat and light of the Sun sustain life here on Earth, and the life cycles of stars that existed billions of years ago produced the elements of which we are made and that of the planet on which we live. This chapter will discuss the properties of stars in general, how these are measured, and where our own star, the Sun, is positioned amongst them.
Stellar luminosity
Stars have a very wide range of intrinsic luminosity – their energy output across the whole electromagnetic spectrum. The luminosity (3.86 × 1026 W) of our Sun, Lsun, is taken as the reference point. The Sun actually turns out to be quite a good star to take as the reference luminosity, as it lies roughly halfway (on a logarithmic scale) between the faintest and brightest stars.
- Type
- Chapter
- Information
- A Journey through the UniverseGresham Lectures on Astronomy, pp. 133 - 144Publisher: Cambridge University PressPrint publication year: 2014