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11 Cephei — Star in Cepheus

Magnitude 4.6m Star Cepheus (Cep) Visible
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1Physical Properties

Magnitude 4.56
Spectral Type K1III giant
Star Color Orange (B-V 1.10)
Distance 408 ly

2Position & Identifiers

RA 21h 41m 55.3s
Dec +71° 18' 41.0"
Constellation Cepheus (Cep)
HR 8317
HIP 107119
HD 206952
SAO 10126
Flamsteed 11 Cep
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 Jul – Sep (peak: Aug)

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

Discover

14

Light Travel Time Machine

15

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.

Alfirk
HIP 106032; Beta Cephei; 8 Cephei
Easy
Hot blue O-type star
Double Star mag 3.23 1.3° Cepheus
T Cep
Medium
Mira-type variable, range 5.2–11.3
Variable Star mag 7.33 4.0° Cepheus
Iris Nebula
NGC 7023
Medium+
Reflection nebula around a bright star
Reflection Nebula mag 6.8 4.7° Cepheus
NGC 7142
Easy
Open cluster
Open Cluster mag 9.3 5.5° Cepheus
Show on Map

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Mythology, bright stars, and deep-sky highlights.
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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.
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