Canis Minor
What is Canis Minor?
Constellations· Winter evenings (N) · eastern corner of the Winter Triangle. Orion's lesser hunting dog — just two stars, but Procyon completes the Winter Triangle with Betelgeuse and Sirius. The name means "before the dog", because it rises a little ahead of Sirius.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Canis Minor is in your sky right now: https://nowsky.org/solar/sky?sel=con:Canis Minor — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Procyon | 0.4 |
The 1 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.
Constellation basics
| Season | winter evenings, January–March |
|---|---|
| Brightest star | Procyon (0.4) |
| How to find | the star completing an equilateral triangle with Betelgeuse and Sirius |
| Area rank | 71st of 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Canis Minor?
- winter evenings, January–March.
- How do I find Canis Minor?
- the star completing an equilateral triangle with Betelgeuse and Sirius.
- What is the brightest star in Canis Minor?
- Procyon, magnitude 0.4.
- Where is Canis Minor in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
A companion found by calculation before it was seen — Procyon B
In 1844 Bessel found that Sirius and Procyon did not move in straight lines but wobbled as they went. He concluded that unseen heavy companions were tugging each of them; Sirius's partner was found soon after, in 1862, but Procyon's was so much fainter that it waited half a century until Schaeberle found it in 1896 with the 36-inch telescope at Lick Observatory.
Procyon B is an 11th-magnitude white dwarf tucked within five arcseconds of 0.4-magnitude Procyon, drowned in the bright star's glare; even today it takes a large telescope and special techniques to separate them. The chief star of a constellation of only two stars turned out to carry an invisible companion predicted by Newtonian mechanics, and the fulfilment of that prediction stands as an early case of an existence settled before it was observed.
The constellation in depth
Canis Minor is the second of Orion's hounds, or Maera, the faithful dog who led a daughter to her murdered father's grave. Egyptians and Greeks saw the star that appears just before Sirius as the dog's herald, and the name Procyon, "before the dog", records exactly that. The constellation was already listed by Ptolemy in the second century, one of the 48 figures he catalogued in the Almagest.
Procyon is a neighbour 11.5 light-years away, a subgiant slightly larger and brighter than the Sun. Like Sirius it has a white-dwarf companion, Procyon B, circling it every 40 years. With only Procyon and Gomeisa of any brightness, the constellation is drawn as a single line — one of the simplest figures in the sky. The companion, found in 1896, is far fainter than its primary and needs a large telescope to separate.
On winter evenings find red Betelgeuse in Orion and Sirius to its southeast; the star to the east that makes an equilateral triangle with them is Procyon, and the three form the Winter Triangle. Gomeisa sits close to Procyon's northwest. Set the Sky view to a February evening to fit the whole triangle on screen. Gomeisa is a hot blue-white star that spins rapidly, throwing off a disk of gas that makes it a mild variable.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.