Menu

Kappa Canis Majoris — Star in Canis Major

Magnitude 3.8–4.0m Star Canis Major (CMa) Visible
Star Map
+ List + Plan

Observe

1Physical Properties

Magnitude 3.96
Range 3.40 - 3.97
Variable Type Gamma Cassiopeiae (Eruptive Be Star)
Spectral Type B1.5Ve
Star Color Blue (B-V -0.23)
Distance 658 ly

2Position & Identifiers

RA 06h 49m 50.5s
Dec -32° 30' 31.0"
Constellation Canis Major (CMa)
HR 2538
HIP 32759
HD 50013
SAO 197258
Bayer Kappa
Flamsteed 13 CMa
Variable ID Kap CMa
SIMBAD

3How easy to spot?

Sign in and configure your equipment and default location to see a personalized row.
Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Easy Medium+ Medium
50mm finder Easy Easy Easy
150mm scope Easy Easy Easy
Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

4Visibility

Set a location in User Settings to see visibility data.

Best season Nov – Jan (peak: Dec)

5Survey Image

Loading survey image…

Explore

7

Size Comparison

Querying VizieR for stellar data…
8

Compare Stars

9

Spectral Classification

10

Hertzsprung-Russell Diagram

Loading HR diagram…
Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map
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

Gamma Cas 3.78 - 3.97V, 3.7 - 3.85B.
H alpha emission; typical shell spectrum. Equivalent width of H alpha is variable.
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.

HP CMa
Easy
Easy double, sep 5.0″
Double Star mag 5.80 1.8° Canis Major
NGC 2298
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 9.4 3.5° Puppis
NGC 2243
Easy
Open cluster
Open Cluster mag 9.4 4.5° Canis Major
NGC 2325
Medium+
Elliptical galaxy
Galaxy mag 11.2 4.7° Canis Major
Show on Map

Explore Nightbase

Related knowledge, tools, and stories — no observation planning required.

Arthur Eddington
1919 eclipse expedition confirming general relativity; first theory of stellar interiors; the Eddington limit
Biography
The Hertzsprung-Russell Diagram — Reading Stars Like a Map
The HR diagram turns the night sky into a physics map: every named star has a spot, every spot tells you mass, age, and fate. A guide for amateur observers.
Article
Canis Major
Mythology, bright stars, and deep-sky highlights.
Constellation
}