# Procyon (Alpha Canis Minoris)

Procyon (Alpha Canis Minoris) is a star in the constellation Canis Minor, magnitude 0.4.

**The Little Dog’s bright eye, rising just before Sirius — with a faint white dwarf in tow.**

Its name is Greek for ‘before the dog’: for observers in the north, Procyon rises shortly ahead of Sirius, the Dog Star. It is one of our nearest stellar neighbours, a [star](https://astropilot.space/glossary/star) somewhat bigger than the Sun — 1.5 times its mass, twice its width and seven times as bright. It has nearly finished fusing the hydrogen in its core. Within 10 to 100 million years it will swell to 80–150 times its present size and glow orange or red.

Like Sirius, it has a ghostly partner. Friedrich Bessel suspected an unseen companion in 1844 from Procyon’s wobble, and Arthur Auwers calculated its orbit in 1862. John Martin Schaeberle finally saw it in 1896, right where predicted, with Lick Observatory’s great 36-inch refractor. Procyon B is a white dwarf, the cooling core of a star that died about 1.2 billion years ago. The two circle each other every 41 years.

Procyon (Alpha Canis Minoris) is 11.5 light-years away: the light we see from it set off in 2015, 6 years before the James Webb Space Telescope was launched.

## Did you know?

- **The Carpenter.** To the Babylonians Procyon was Nangar, the Carpenter — an aspect of the god Marduk, who built and ordered the sky.
- **Wolves round a plough.** In Macedonian folklore Procyon and Sirius were wolves, circling hungrily around Orion — which they saw as a plough pulled by oxen.
- **Lighter but larger.** Procyon B has less mass than Sirius B, yet it is bigger. In the crushed matter of a white dwarf, less mass means a larger star.

A bright white star with a faint yellow tinge, the only bright star in Canis Minor. It makes a big, nearly equilateral triangle with Sirius and Betelgeuse. Compare it with Sirius: Procyon is a little warmer in colour.

## When and where to see it

It is best placed in the evening sky around February, when it crosses the meridian at about 10 pm local time (around midnight in January). It can be seen from everywhere north of 85°S and never sets north of 85°N.

At its highest it stands 45° up from 50°N, 60° up from 35°N, 85° up from the equator, 50° up from 35°S.

## Facts

- Type: Star
- Constellation: Canis Minor
- Designations: Alpha Canis Minoris, α CMi, 10 CMi, HR 2943, HD 61421, HIP 37279
- Magnitude: 0.4
- Position: RA 7h 39.3m, Dec +5° 13′ (J2000)
- Spectral type: F5IV-V+DQZ
- Colour: yellow-white (B−V 0.42)
- Distance: 11.5 light-years
- Discovered: Known since antiquity; its white-dwarf companion was first seen by John Martin Schaeberle in 1896

Open AstroPilot to see when Procyon (Alpha Canis Minoris) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view. https://astropilot.space/object/procyon