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Rho Geminorum — Star in Gemini

Magnitude 4.2m Star Gemini (Gem) Visible
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Observe

1Physical Properties

Magnitude 4.18
Spectral Type F0V
Star Color Yellow-white (B-V 0.32)
Distance 53 ly

2Position & Identifiers

RA 07h 29m 06.7s
Dec +31° 47' 04.0"
Constellation Gemini (Gem)
HR 2852
HIP 36366
HD 58946
SAO 60118
Bayer Rho
Flamsteed 62 Gem
Double Cat 6109
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 Dec – Feb (peak: Jan)

5Survey Image

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7

Size Comparison

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8

Compare Stars

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

Discover

15Stellar Notes

B, 12.5v at 3" CPM.
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.

Castor
HIP 36850; Alpha Geminorum; 66 Geminorum
Easy
Easy double, sep 5.7″
Double Star mag 1.98 1.2° Gemini
NGC 2331
Easy
Open cluster
Open Cluster mag 9.0 6.6° Gemini
NGC 2419
Medium+
Globular cluster — dense ball of ancient stars
Globular Cluster mag 10.4 7.3° Lynx
NGC 2424
Hard+
Edge-on galaxy
Galaxy mag 12.6 7.8° Lynx
Show on Map

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