Canopus is a rare example of a supergiant of spectral type F. Canopus is essentially white when seen with the naked eye (though F-type stars are sometimes listed as "yellowish-white"). It is located in the far southern sky, at a declination of −52° 42' (2000) and a right ascension of 06h24.0m.
Canopus is 15,000 times more luminous than the Sun and the most intrinsically bright star within approximately 700 light years. For most stars in the local stellar neighborhood, Canopus would appear to be one of the brightest stars in the sky. Canopus is out-shone by Sirius in our sky only because Sirius is far closer to the Earth (8 light years).
Its surface temperature has been estimated at 7350 ± 30 K. Its diameter has been measured at 0.6 astronomical units (the measured angular diameter being 0.006 arcseconds), 65 times that of the sun. If it were placed at the centre of the solar system, it would extend three-quarters of the way to Mercury. An Earth-like planet would have to lie three times the distance of Pluto.
Canopus is part of the Scorpius-Centaurus Association, a group of stars which share similar origins.
The other etymology of the name is that it comes from the Egyptian Coptic Kahi Nub ("Golden Earth"), which refers to the way it would appear near the horizon in Egypt and be correspondingly reddened by atmospheric extinction from that position. There is also a ruined ancient Egyptian port, Canopus, apparently specifically named for the star, near the mouth of the Nile; its site was the location of the Battle of the Nile. (Or it could be that Menelaus's legendary pilot was named after the port, and the port was named the "Golden Floor" because of the many valuable cargoes that passed across its quays and the profits made by merchants there.)
A third possibility is its origin from the Semitic root G(C)-N-B (Gimal-Nuun-Beth), which in Arabic is Janub (جنوب ). The southeastern wall of the Muslim Ka'bah points to Canopus, and is named Janub as well.
It is known as 老人星(Lǎorénxīng, the Star of the Old) in Chinese, and سهيل (Suhayl) in Arabic.
In Ancient Hindu astronomy and astrolog, Canopus is named Agasti or Agastiya.
In modern times, Canopus serves another navigational use. Canopus' brightness and position away from the orbital plane of our solar system means it is often used by American space probes for navigational purposes, using a special camera known as a "Canopus Star Tracker" in combination with a "Sun Tracker".
The effects of precession will take Canopus within 10° of the south celestial pole around the year 14,000 AD.
To the Bedouin people of the Negev and Sinai, Canopus is known as Suhayl. It and Polaris are the two principal stars used for navigation at night. Due to the fact that it disappears below the horizon, it became associated with a cowardly or changeable nature, as opposed to always-visible Polaris, which was circumpolar and hence 'steadfast'.