Star
The Sun has an apparent magnitude of −26.7, but its absolute magnitude is only +4.83. Sirius, the brightest star in the night sky as seen from Earth, is approximately 23 times more luminous than the Sun, while Canopus, the second brightest star in the night sky with an absolute magnitude of −5.53, is approximately 14,000 times more luminous than the Sun. Despite Canopus being vastly more luminous than Sirius, however, Sirius appears brighter than Canopus. This is because Sirius is merely 8.6 light-years from the Earth, while Canopus is much farther away at a distance of 310 light-years.
Auriga (constellation)
Alpha Aurigae (Capella), the brightest star in Auriga, is a G8III class star (G-type giant) 43 light-years away and the sixth-brightest star in the night sky at magnitude 0.08. Its traditional name is a reference to its mythological position as Amalthea; it is sometimes called the "Goat Star". Capella's names all point to this mythology. In Arabic, Capella was called "al-'Ayyuq", meaning "the goat", and in Sumerian, it was called mul.ÁŠ.KAR, "the goat star". On Ontong Java, Capella was called "ngahalapolu". Capella is a spectroscopic binary with a period of 104 days; the components are both yellow giants, more specifically, the primary is a G-type star and the secondary is between a G-type and F-type star in its evolution. The secondary is formally classified as a G0III class star (G-type giant). The primary has a radius of 11.87 solar radii () and a mass of 2.47 solar masses (); the secondary has a radius of and a mass of . The two components are separated by 110 million kilometers, almost 75% of the distance between the Earth and the Sun. The star's status as a binary was discovered in 1899 at the Lick Observatory; its period was determined in 1919 by J.A. Anderson at the 100-inch Mt. Wilson Observatory telescope. It appears with a golden-yellow hue, though Ptolemy and Giovanni Battista Riccioli both described its color as red, a phenomenon attributed not to a change in Capella's color but to the idiosyncrasies of their color sensitivities. Capella has an absolute magnitude of 0.3 and a luminosity of 160 times the luminosity of the Sun, or (the primary is and the secondary is ). It may be loosely associated with the Hyades, an open cluster in Taurus, because of their similar proper motion. Capella has one more companion, Capella H, which is a pair of red dwarf stars located 11,000 astronomical units (0.17 light-years) from the main pair.