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2 Monocerotis — Star in Monoceros

Magnitude 5.0m Star Monoceros (Mon) Visible
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1Physical Properties

Magnitude 5.03
Spectral Type A6IIIm vs bright giant
Star Color Yellow-white (B-V 0.19)
Distance 326 ly

2Position & Identifiers

RA 05h 59m 04.3s
Dec -09° 33' 30.0"
Constellation Monoceros (Mon)
HR 2108
HIP 28325
HD 40536
SAO 132715
Flamsteed 2 Mon
SIMBAD

3How easy to spot?

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Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Medium Medium Hard+
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

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Best season Nov – Jan (peak: Dec)

5Survey Image

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6

Size Comparison

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7

Compare Stars

8

Spectral Classification

9

Hertzsprung-Russell Diagram

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Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map
10

Stellar Lifecycle

11

Blackbody Spectrum

12

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

13

Stellar Fusion

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14Stellar Notes

9.3553d, K 57.1k/s, V0 +22.2k/s, asini 7.18.
15

Light Travel Time Machine

16

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.

1 Mon
Hard+
Variable star, range 5.9–6.4
Variable Star mag 6.12 0.2° Monoceros
3 Mon
Hard+
Tight double — a rewarding split at 2.0″
Double Star mag 4.95 1.2° Monoceros
Saiph
HIP 27366; Kappa Orionis; 53 Orionis
Easy
Bright naked-eye star, mag 2.1
Star mag 2.06 2.8° Orion
NGC 2182
Medium+
Reflection nebula around a bright star
Reflection Nebula mag 9.00 4.1° Monoceros
NGC 2215
Easy
Open cluster
Open Cluster mag 8.4 5.8° Monoceros
Show on Map

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