Can you see it? Sirius B amid telescope diffraction spikes. Credit: NASA\/McDonald Observatory. <\/p>\n
Astronomy is all about thinking big, both in time and space. <\/p>\n
The Earth turns on its axis, the Moon passes through its phases, and the planets come into opposition and solar conjunction on a routine basis. <\/p>\n
Of course, on the other end of the spectrum, there are some events which traverse such colossal spans of time that the mere mortal life span of measly homo sapiens such as ourselves can never expect to cover them. Many comets have periods measured in centuries, or thousands of years. The axis of the Earth wobbles like a top, completing one turn every 26,000 years in whats known as the Precession of the Equinoxes. Our solar system completes one revolution about the galactic center every quarter billion years <\/p>\n
Feeling puny yet? Sure, astronomy is also about humility. But among these stupendous cycles, there are some astronomical events that you just might be able to live through. One such instance is the orbits of double stars. And as 2015 approaches, we challenge you to see of the most famous white dwarf of them all, as it reaches a favorable viewing position over the next few years: Sirius B. <\/p>\n
Sirius A and B in x-rays courtesy of Chandra. Credit: NASA\/SAO\/CXC. <\/p>\n
Sirius itself is easy to find, as its the brightest star in Earths sky shining at magnitude -1.42. In fact, you can spot Sirius in the daytime skyif you know exactly where to look. <\/p>\n
But it is one of the ultimate in cosmic ironies that the most conspicuous of stars in our sky also hosts such an elusive companion. The discovery of Sirius B awaited the invention of optics capable ofresolving it next to its dazzling host. Alvan Clark Jr. and Sr. first spied the enigmatic companion on January 31st, 1862 while testing their newly constructed 18.5 inch refractor, which was the largest at the time. The discovery was soon verified from the Harvard College Observatory, adding Sirius A and B to the growing list of multiple stars. <\/p>\n
A 19th century refractor similar to the one used to discover Sirius B. Photo by the author. <\/p>\n
And what a strange companion it turned out to be. Today, we know that Sirius B is a white dwarf, the cooling dense ember of a main sequence star at the end of its life. We call the matter in such a star degenerate, not as a commentary on its moral stature, but the state the electrons and the closely packed nuclei within under extreme pressure. Our Sun will share the same ultimate fate as Sirius B, about six billion years from now. <\/p>\n
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Astro-Challenge: Taming the Pup-Can You Glimpse Sirius B?<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Can you see it? Sirius B amid telescope diffraction spikes. Credit: NASA\/McDonald Observatory Continue reading