Kappa Pegasi — Double Star in Pegasus
Observe
1Physical Properties
Magnitude
4.13
Spectral Type
F5IV
subgiant
Star Color
Yellow-white
(B-V 0.43)
Distance
93 ly
2Position & Identifiers
RA
21h 44m 38.7s
Dec
+25° 38' 42.0"
Constellation
Pegasus
(Peg)
HR
8315
HIP
107354
HD
206901
SAO
89949
Bayer
Kappa
Flamsteed
10 Peg
Double Cat
15281
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 Triple
Components
3 (triple)
Component IDs
AB
Separation
0.2″
Companion Mag
5.0
Companion Sp
G9III
Position Angle
134°
Star Colors
A: Yellow-white
B: Orange
Discoverer
BU 989
AB 4.7 F2IV, 5.0 F6IV, 11.558y, a = 0.255". ADS 15281C, 10.8v at 13.8" possibly in hyperbolic orbit about AB or is | optical.
Separation over time
Period: 11.6 y
Eccentricity: 0.314
Now: 0.18", PA 289°
+ 0.02" in 5 years
Apparent separation over time, computed from ORB6 orbital elements. Steep curves indicate fast-changing pairs — catch them while they're splittable.
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
Discover
15Stellar Notes
ADS 15281B, 5.97152d, K 34.2k/s, V0 -5.7k/s, asini 2.803. ADS component B the more massive. Component A, SB2, | 4.77d, disproved; A is single. B resolved by speckle interferometry 1983.93, sep. 0.10".
0.024".
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.
Mu Cyg
Mu Cyg (BS8309)
Tight double — a rewarding split at 1.4″
Double Star
mag 4.73
3.1°
Cygnus
HO Peg
Semi-regular variable, range 6.1–6.6
Variable Star
mag 6.89
4.7°
Pegasus
NGC 7217
Bright spiral galaxy
Galaxy
mag 10.2
7.7°
Pegasus
V389 Cyg
Easy double, sep 3.3″
Double Star
mag 5.59
9.2°
Cygnus
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