Canopus (α Carinae)
Soheyl (#), Agast (#), Parak (#)
The brightest star in the → constellation → Carina and the second brightest star in the sky with a → visual magnitude -0.72. Also called α Carinae and HD45348. Canopus is not visible from latitudes above 37 degrees north. It is an evolved star, a → supergiant of type F0 II (Smiljanic et al., 2006, A&A 449, 655). Canopus lies 310 → light-years (96 → parsecs) from the Solar System; this is based on its → Hipparcos → parallax measurement of 10.43 mas (5% accuracy). From this distance a → luminosity 13,300 times that the → solar luminosity is derived, and a radius of 73 times solar, in agreement with the → angular size (6.95 ± 0.15 mas) measured using → interferometry (Cruzalèbes et al., 2013, arXiv:1306.3288). These observations also yield an → effective temperature of about 7400 K. The star's mass is estimated to be about 8 Msun. Canopus possesses an extremely hot magnetically heated → corona. Canopus's corona is some 10 times hotter than the → solar corona and produces both observable → X-rays and → radio emission. According to calculations by J. Tomkin (1998, Sky & Telescope 95, 59), using → Hipparcos data, Canopus has, in the past, been the brightest star during three periods: from 3,700,000 to 1,370,000 years ago, from 950,000 to 420,000 years ago, and from 160,000 to 90,000 years ago. It will, once more, become the brightest star in 480,000 years and will remain such for 510,000 years.
Canopus, from Gk. kanobos, perhaps from Coptic language Kahi Nub "golden earth."
Soheyl, from Ar. Suhail.