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30 Geminorum — Star in Gemini

Magnitude 4.5m Star Gemini (Gem) Visible
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1Physical Properties

Magnitude 4.49
Spectral Type K0IIICN1Ca1 giant
Star Color Red (B-V 1.16)
Distance 466 ly

2Position & Identifiers

RA 06h 43m 59.3s
Dec +13° 13' 40.0"
Constellation Gemini (Gem)
HR 2478
HIP 32249
HD 48433
SAO 96051
Flamsteed 30 Gem
Double Cat 5387
SIMBAD

3How easy to spot?

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Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Medium+ 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

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Best season Nov – Jan (peak: Dec)

5Survey Image

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7

Size Comparison

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8

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9

Spectral Classification

10

Hertzsprung-Russell Diagram

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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

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15Stellar Notes

Optical.
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.

38 Gem
Easy
Easy double, sep 7.4″
Double Star mag 4.65 2.6° Gemini
NGC 2259
Medium+
Open cluster
Open Cluster mag 11.0 2.7° Monoceros
NGC 2247
Medium+
Reflection nebula around a bright star
Reflection Nebula mag 8.50 3.9° Monoceros
BL Ori
Medium
Semi-regular variable, range 5.9–6.6
Variable Star mag 6.24 4.7° Orion
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