Nu Canis Majoris — Star in Canis Major
HIP 31592; Nu Canis Majoris; 7 Canis Majoris
About Nu CMa
Description
Nu Canis Majoris is a K-type giant of spectral class K1 III about 64.4 light-years away — relatively nearby for its spectral type. It shines at magnitude 3.95 in the northern part of Canis Major. Nu CMa is a red-clump giant actively fusing helium in its core.
Observing Tips
Nu CMa sits north of Sirius in Canis Major. In binoculars it is a warm yellow-orange naked-eye point. Best observed December through April.
History
Nu CMa retains its Bayer designation in current IAU catalogs.
Fun Facts
Nu CMa's proximity makes it one of the closer naked-eye K-giants to the Sun — useful for fundamental stellar-properties calibration via high-precision parallax from Gaia. The star is about 4 billion years old, comparable to the Sun's age, and has expanded to many times its original radius during its evolution.
Observe
1Physical Properties
2Position & Identifiers
3How easy to spot?
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Easy | Medium+ | Medium |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Survey Image
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Explore
7
Size Comparison
8
Compare Stars
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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
15
Exoplanets
2 known planets
View in 3D
| Planet | Radius | Mass | Period | Distance |
|---|---|---|---|---|
| 7 CMa b | 13.40R⊕ | 1.85M♃ | 2.0yr | 65ly |
| 7 CMa c | 13.90R⊕ | 0.87M♃ | 2.7yr | 65ly |
Habitable Zone
Size & Mass Comparison
About exoplanets — how we find them and which host stars you can observe
Discover
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.
