Canopus, the second-brightest star

Canopus is the second-brightest star in the night sky, in the southern constellation Carina. From much of the Northern Hemisphere it never rises at all, which is why many people have never heard of it.

Where is it from where I am?

How to spot it: About 36° south of Sirius: three and a half fists at arm's length. Source (opens in a new tab)

What you are looking at

In the Hipparcos measurements Canopus is magnitude −0.62, second only to Sirius (opens in a new tab). ESA's table gives no distance for it, and this page does not guess one.

How to find it

Canopus lies about 36° south of Sirius, by this site's calculation from the catalogue. A fist held at arm's length covers about 10 degrees (opens in a new tab), so it is three and a half fists from Sirius toward the south.

A spacecraft's guide star

A spacecraft far from Earth needs something fixed to point by. NASA's Mariner probes to Mars used the Sun and a second reference, Canopus (opens in a new tab): a sensor locked onto the star to hold the craft's orientation and aim its instruments. In 1969 Mariner 7's sensor was briefly distracted by bright specks of dust and had to search for the star again.

Where on Earth, and when

It rises from anywhere south of about 37°N.

South of about 37°S, it never sets.

It climbs at least 20° high, the finder's threshold for a suggestion, from anywhere south of about 17°N.

It is highest in the evening sky, at about 9 p.m. local time, in mid-February, from either hemisphere, wherever it rises. With daylight saving time, that is nearer 10 p.m. on the clock.

Worked out by this site from the Bright Star Catalogue, for a flat, clear horizon. Hills, buildings, haze and city light all cut into this; the air also lifts objects near the horizon by about half a degree. For your own place and night, use the sky finder.