9 Cephei — Double Star in Cepheus
Observe
1Physical Properties
Magnitude
4.73
Range
4.69 - 4.78
Period
11.0 days
Variable Type
ACYG
Spectral Type
B2Ib
supergiant
Star Color
Yellow-white
(B-V 0.30)
2Position & Identifiers
RA
21h 37m 55.2s
Dec
+62° 04' 55.0"
Constellation
Cepheus
(Cep)
HR
8279
HIP
106801
HD
206165
SAO
19541
Flamsteed
9 Cep
Variable ID
V337 Cep
Querying VizieR catalog...
3How easy to split?
Primary
4.7 mag
Companion
10.2 mag
Separation
35.0″
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| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Medium+ | Medium | Hard+ |
| 150 mm Newton 150mm Newt. | Easy | Medium+ | Medium+ |
| Celestron C8 (203 mm SCT) C8 203mm | 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
Jul – Sep
(peak: Aug)
5Light Curve
6Multiple Star System
Separation
35.0″
Companion Mag
10.2
Position Angle
20°
Star Colors
A: Yellow-white
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
A: 4.7 · B: 10.2 · Sep: 35.0″ · PA: 20° · N up, E right
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
Explore
7
Size Comparison
Querying VizieR for stellar data…
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
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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
Alpha Cyg 4.69 - 4.78V. H alpha profile var.
Cep OB2.
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 7160
Rich open cluster
Open Cluster
mag 6.1
1.9°
Cepheus
Kurhah
HIP 108917; Xi Cephei; 17 Cephei
Easy double, sep 8.2″
Double Star
mag 4.29
3.9°
Cepheus
T Cep
Mira-type variable, range 5.2–11.3
Variable Star
mag 7.33
7.1°
Cepheus
Iris Nebula
NGC 7023
Reflection nebula around a bright star
Reflection Nebula
mag 6.8
7.2°
Cepheus
Alfirk
HIP 106032; Beta Cephei; 8 Cephei
Hot blue O-type star
Double Star
mag 3.23
8.5°
Cepheus
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