Menu

Gamma Monocerotis — Star in Monoceros

Magnitude 4.0m Star Monoceros (Mon) Visible
Star Map
+ List + Plan

Observe

1Physical Properties

Magnitude 3.98
Spectral Type K1.5IIIBa0.3 giant
Star Color Red (B-V 1.32)
Distance 251 ly

2Position & Identifiers

RA 06h 14m 51.3s
Dec -06° 16' 29.0"
Constellation Monoceros (Mon)
HR 2227
HIP 29651
HD 43232
SAO 133012
Bayer Gamma
Flamsteed 5 Mon
Double Cat 4853
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

Called Alpha Mon in BAC and many early catalogues. Now HR 2970 is called Alpha Mon.
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.

NGC 2182
Medium+
Reflection nebula around a bright star
Reflection Nebula mag 9.00 1.3° Monoceros
NGC 2215
Easy
Open cluster
Open Cluster mag 8.4 1.8° Monoceros
Beta Mon
HIP 30867; Beta Monocerotis; 11 Monocerotis
Easy
Easy double, sep 7.3″
Double Star mag 4.60 3.5° Monoceros
1 Mon
Hard+
Variable star, range 5.9–6.4
Variable Star mag 6.12 5.0° Monoceros
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 Life of Stars
From birth in a nebula to spectacular death — how stars are born, shine, swell, and die, and how to read the clues in their starlight.
Article
Monoceros
Mythology, bright stars, and deep-sky highlights.
Constellation
}