# Sirius B. Sirius B is a white dwarf. There was no such thing as Sirius B until 1862 when Alvan Clark discovered it while testing one of the best optical.

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Sirius B

Sirius B is a white dwarf. There was no such thing as Sirius B until 1862 when Alvan Clark discovered it while testing one of the best optical telescopes in the world, at the time. They didn’t know anything of it because Sirius A is so bright.

Sirius B orbits Sirius A. Since the discovery of Sirius B, scientists have been agitated and frustrated because Sirius A is so bright that they can’t observe and weigh Sirius A. Sirius is located in the constellation Canis Major.

Sirius has a surface temperature of 25,000 degrees Celcius, which produces very low energy X-rays. Sirius B is 10, 000 times dimmer than Sirius A. Sirius B has a mass equal to the mass of the Sun, packed into a diameter that is 90% that of the Earth.

The theory of white dwarf stars was developed by S. Chandrasekhar, his name came from the Chandra X-ray Observatory. The story of Sirius B came full known when it was observed by Chandra in October 1999 during the test period.

Sirius B is not a normal star; its spectrum and luminosity indicates that it is hot, but extremely small. The reason is that the spectrum contains pressure-broadened hydrogen lines, implying a surface environment with a higher density than what a normal star would have. Assuming the spectrum of Sirius B being a blackbody and using the well-established distance to Sirius, we think that from its luminosity, Sirius B’s radius is only about 5,800 km. According to Kepler’s law, we can infer that the mass of Sirius B is about 1.03 M.

 The gravity on Sirius B is 400,000 times more than gravity on Earth!!  One teaspoon of a white dwarf would way 5 tons  In 1844, Sirius B was predicted because of the motion of Sirius A. Even though, Sirius B wasn’t seen until 1862!  The average mass of a star is 0.58 M, when Sirius B’s mass is 1.03 M.

Sirius B is a white dwarf star. It is way less brighter than Sirius A. It orbits Sirius A and would way a lot just to pick a little bit of it up. It is a well-known star that is good for observing.

1. Sirius B is in the main sequence. a. True b. False

2. What star does Sirius B orbit? a. Polaris b. Vega c. Sirius A d. Altair

3. When was Sirius B discovered? a. 2010 b. 1862 c. 1831 d. 1926

4. What type of star is Sirius B? a. Blue giant b. Red giant c. White dwarf d. Yellow-white super giant

5. What constellation is the star located in? a. Canis Major b. Ursa Major c. Lyra d. Aquila

 http://www.ufodigest.com/siriusb.html  http://space.about.com/od/stars/p/siriusinfo.htm  http://chandra.harvard.edu/photo/2000/0065/  http://hyperphysics.phy- astr.gsu.edu/hbase/astro/whdwar.html#c2  http://hyperphysics.phy- astr.gsu.edu/hbase/astro/whdwar.html  http://eagle.phys.utk.edu/guidry/astro411/lectures/lecture_c h12.pdf

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