Sirius is the brightest star in the nighttime sky, with a visual apparent magnitude of -1.46. It is located in the constellation Canis Major. Its name comes from the Latin sirius, from Greek (seirios, "glowing"). It is situated in the eye of the greater dog Canis Major, therefore it is known as the Dog Star.
Sirius can be seen from every inhabited region of the Earth's surface and, in the Northern Hemisphere, is known as a vertex of the Winter Triangle. At a distance of 2.6 pc or 8.57 light years, Sirius is also one of the nearest stars to Earth. The best time of year to view it is around January 1, when it reaches the meridian at midnight.
To locate Sirius ... When looking at the constellation Orion, locate Orion's belt which are the three bright stars in a row. Follow an imaginary line through these stars to Sirius which is just above the horizon.
Sirius B
From 1834 to 1844 some irregularities were noticed in the movement of Sirius by F.W. Bessel. It was supposed that Sirius must be affected by a second star, and in 1862 a faint companion star was finally detected by Alvan Clark, and it was named Sirius B.
In 1862 Alvan Graham Clark discovered the companion, which is called Sirius B, or affectionately "the Pup". The visible star is now sometimes known as Sirius A. The two stars orbit each other with a separation of about 20 AU and a period of close to 50 years.
In 1915 astronomers at the Mount Wilson Observatory determined that Sirius B was a white dwarf star , the first to be discovered. This means that Sirius B must have originally been by far the more massive of the two, since it has already evolved off the main sequence.
Sirius is the brightest star in the nighttime sky, with a visual apparent magnitude of -1.46. It is located in the constellation Canis Major. Its name comes from the Latin sirius, from Greek (seirios, "glowing"). It is situated in the eye of the greater dog Canis Major, therefore it is known as the Dog Star.
Sirius can be seen from every inhabited region of the Earth's surface and, in the Northern Hemisphere, is known as a vertex of the Winter Triangle. At a distance of 2.6 pc or 8.57 light years, Sirius is also one of the nearest stars to Earth. The best time of year to view it is around January 1, when it reaches the meridian at midnight.
To locate Sirius ... When looking at the constellation Orion, locate Orion's belt which are the three bright stars in a row. Follow an imaginary line through these stars to Sirius which is just above the horizon.
Sirius B From 1834 to 1844 some irregularities were noticed in the movement of Sirius by F.W. Bessel. It was supposed that Sirius must be affected by a second star, and in 1862 a faint companion star was finally detected by Alvan Clark, and it was named Sirius B.
In 1862 Alvan Graham Clark discovered the companion, which is called Sirius B, or affectionately "the Pup". The visible star is now sometimes known as Sirius A. The two stars orbit each other with a separation of about 20 AU and a period of close to 50 years.
In 1915 astronomers at the Mount Wilson Observatory determined that Sirius B was a white dwarf star , the first to be discovered. This means that Sirius B must have originally been by far the more massive of the two, since it has already evolved off the main sequence.