Planets in the Sirius Star System

Sirius A

• According to Sirius Link, the Sirius star system is more than 20 times brighter than the sun, and Sirius A is the star that makes this system so bright. Sirius A is about two times the size of the sun and is closer to Earth than most stars. It is believed to be about 200 to 300 million years old and originally blue in tint -- now it appears white. Being part of the Canis Major constellation, Sirius A is sometimes called the Dog Star. It is the primary star in the binary system.

Sirius B

• Sirius B is the companion star in the binary system and is 10,000 times dimmer than its primary star. Sirius Link notes that it was the first discovered white dwarf star, found in 1930 by American astrophysicist Subrahmanyan Chandrasekhar. Sirius A and Sirius B orbit at a common center of mass. According to Crystalinks, Sirius B holds almost the entire mass of the sun in a globe four times the size of Earth, causing the surface to be 300 times harder than diamonds. NASA astrophysicist Jonathan Keohane explains that 100 Earths lined up next to each other could span the face of the sun.

Sirius C

• In 1995, French researchers Daniel Benest and J.L. Duvent wrote the essay "Is Sirius a Triple Star?" believing they had discovered a Sirius C in the Sirius star system. The scientists believe that the orbital pattern of the Sirius star system suggests the existence of a third star. Sirius C is thought to be a small brown dwarf star, about one-twentieth the size of Sirius B, but it has yet to be confirmed.

Debate over Sirius C

• Researchers Daniel Benest and J.L. Duvent make the claim that a tiny star within the Sirius star system had been observed about 20 times between 1920 and 1930. The scientists were unable to determine whether Sirius C orbited around Sirius A or Sirius B -- or both of them together -- but found that there could be a stable elliptical orbit of Sirius C around Sirius A for a six-year period. While the scientists have accumulated a following of people who believe a Sirius C exists, the star has yet to be officially acknowledged.