Procyon — Double Star in Canis Minor
HIP 37279; Alpha Canis Minoris; 10 Canis Minoris
About Procyon
Description
Procyon is the eighth brightest star in the sky at magnitude 0.38, a yellow-white subgiant of spectral type F5IV-V located only 11.5 light-years from Earth. Like Sirius, it has a white dwarf companion (Procyon B), making it a binary system with an orbital period of about 41 years. Procyon's luminosity is about 7 times solar, and it has begun evolving off the main sequence.
Observing Tips
Procyon forms the Winter Triangle together with Sirius and Betelgeuse — three bright stars from three different constellations. It is easily found as the bright star east of Orion and north of Sirius in the small constellation Canis Minor. Its slightly yellow-white color distinguishes it from the bluer Sirius. Best observed January through April.
History
The name Procyon means 'before the dog' in Greek, because it rises before Sirius (the Dog Star) when viewed from mid-northern latitudes. Its white dwarf companion was predicted by Friedrich Bessel in 1844 (the same year he predicted Sirius B) based on wobbles in Procyon's proper motion, and was first observed in 1896 by John Schaeberle.
Fun Facts
Procyon is one of the nearest stars to the Sun and one of only a handful of bright stars with a white dwarf companion. Its impending evolution into a giant star means it is slowly brightening — in a few million years it will expand to many times its current size and become a prominent orange giant.
Observe
1Physical Properties
2Position & Identifiers
3How easy to split?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | V. hard | V. hard | V. hard |
| 150 mm Newton 150mm Newt. | V. hard | V. hard | V. hard |
| Celestron C8 (203 mm SCT) C8 203mm | V. hard | V. hard | V. hard |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Multiple Star System Quintuple C,G: optical
Separation over time
Apparent separation over time, computed from ORB6 orbital elements. Steep curves indicate fast-changing pairs — catch them while they're splittable.
Eyepiece View
A: 0.4 · B: 11.7 · Sep: 5.1″ · PA: 22° · N up, E right
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
Explore
7
Size Comparison
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
Discover
15Stellar Notes
16
Light Travel Time Machine
17
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
Explore Nightbase
Related knowledge, tools, and stories — no observation planning required.
