This book describes why Sirius has been regarded as an important fixture of the night sky since the beginnings of history. It also examines the part that Sirius has played in how we came to achieve our current scientific understanding of stars.

Sirius - A Diamond in the Night will tell two stories. The first and most obvious is why the star known as Sirius has been regarded as an important fixture of the night sky by many civilizations and cultures since the beginnings of history. A second, but related, narrative is the prominent part that Sirius has played in how we came to achieve our current scientific understanding of the nature and fate of the stars. These two topics have a long intertwined history, and the telling of one story eventually leads back to the other. Presently, new observations from space are revealing, in precise terms, how stars like Sirius and the Sun have evolved and what they will ultimately become, while at the same time answering some of the age-old questions about Sirius.

The book is divided into five parts. The first (Chapters 1 and 2) describes how Sirius was viewed by the ancient civilizations of Egypt, Greece and Rome. The second part (Chapters 3-5) describes how early astronomers sought to determine the nature of the stars, including the prediction that Sirius possessed an unseen companion and the eventual discovery of this white dwarf companion 18 years later. The third part (chapters 6-9) describes the major discoveries in stellar astrophysics revealed by observations of Sirius. The fourth part (chapters 10 and 11) probes the modern scientific and pseudo scientific controversies involving Sirius, including the ‘Red Sirius’ and Dogon tribe stories. The final part (Chapters 12 and 13) highlights modern observations made with the Hubble Space Telescope and other spacecraft of the white dwarf companion.

Of all the fixed stars in the night sky, Sirius is by far the brightest – almost twice as bright as its nearest rival, the star Canopus, which lies too far south to be viewed from most of the Northern Hemisphere. Only the Sun, Moon and the planets Venus, Jupiter and, at times, Mars, appear brighter. Sirius, with its flashing brilliance, is a striking feature of the northern winter sky and has understandably drawn the attention of observers of the night sky for thousands of years.

Sirius has many names.  Astronomers recognize over fifty designations for the star, but the most commonly used is Alpha Canis Majoris, the brightest star in the constellation Canis Major.  This is Latin for the 'Great Dog', which has led to its popular nickname the ‘Dog Star’. Over the centuries many beliefs have come to be associated with Sirius. Some of these beliefs still echo in such phrases as ‘the dog days of summer’, which the ancient Romans understood well. Other old beliefs long ago fell from public consciousness — only to be revived and to grow into modern popular and scientific controversies. Although these beliefs may seem quite recent, many have their origins in the ancient lore surrounding Sirius; humans seem naturally drawn to its brilliance, and a surprising number of modern cults have nucleated around beliefs in which Sirius plays a prominent role.