Pi Cygni — Double Star in Cygnus
HIP 107533; Pi Cygni; 81 Cygni
Observe
1Physical Properties
Magnitude
4.23
Spectral Type
B3III
giant
Star Color
Blue-white
(B-V -0.12)
2Position & Identifiers
RA
21h 46m 47.6s
Dec
+49° 18' 34.0"
Constellation
Cygnus
(Cyg)
HR
8335
HIP
107533
HD
207330
SAO
51293
Bayer
Pi
Flamsteed
81 Cyg
Querying VizieR catalog...
3How easy to spot?
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium+ | Medium+ | Medium |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | 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)
5Multiple Star System
Separation
0.1″
Companion Mag
6.0
Position Angle
131°
Star Colors
A: Blue-white
Discoverer
MIU 3
Explore
7
Size Comparison
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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
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15Stellar Notes
72.0162d, K 7.8k/s, V0 -12.3k/s, asini 7.26.
Cyg OB7.
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.
Cocoon Nebula
IC 5146
Emission nebula — try an OIII filter
Emission Nebula
mag 10.0
2.3°
Cygnus
IC 5146 C
Open cluster
Open Cluster
mag 7.2
2.3°
Cygnus
V1339 Cyg
Semi-regular variable, range 5.9–7.1
Variable Star
mag 6.17
3.6°
Cygnus
60 Cyg
Hot blue O-type star
Double Star
mag 5.37
8.3°
Cygnus
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