Gamma Microscopii
Encyclopedia
Gamma Microscopii (Gamma Mic, γ Microscopii, γ Mic) is the brightest star
in the constellation
of Microscopium. It is a G-type giant star
with an apparent visual magnitude of approximately 4.677, around 220 light-years from the Sun
. Backwards extrapolation of the motion of γ Microscopii has shown that approximately 3.8 million years ago, it was only 6 light-years away from the Sun. It would then have had an apparent magnitude of −3 and have been brighter than Sirius
is now.
, CCDM J21013-3215B, approximately 26 arcseconds away, with an apparent visual magnitude of approximately 13.7. It is believed that this star is not physically bound to γ Microscopii, but is merely an optical companion.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Microscopium. It is a G-type giant star
Giant star
A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...
with an apparent visual magnitude of approximately 4.677, around 220 light-years from the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. Backwards extrapolation of the motion of γ Microscopii has shown that approximately 3.8 million years ago, it was only 6 light-years away from the Sun. It would then have had an apparent magnitude of −3 and have been brighter than Sirius
Sirius
Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris...
is now.
Visual companion
The G-type giant star has a visual companionDouble star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
, CCDM J21013-3215B, approximately 26 arcseconds away, with an apparent visual magnitude of approximately 13.7. It is believed that this star is not physically bound to γ Microscopii, but is merely an optical companion.