Algol (Beta Persei)
Image from Steve Bowers

Algol System - Data Panel

SystemName: Algol
Components: 3
1) Algol (Beta Persei A)
2) (Beta Persei B)
3) (Beta Persei C)
- Distance from Aksijaha: 92.14 ly (J2000)
- Distance from Sol: 89.92 ly (J2000)
- Constellation: Perseus
AlgolNames: Algol, Beta Persei A, 26 Persei A, GJ 9110 A, HD 19356 A, HIP 14576 A, HR 936 A
Physical characteristics:
- Mass: 3.39 x Sol
- Radius: 2.87 x Sol
- Temperature: 12,550 Kelvin
- Luminosity: 184 x Sol (bolometric)
- Spectral type: B8 V
- Rotation period: 2.84 days
- Age: 570 million years
BNames: Beta Persei B, 26 Persei B, GJ 9110 B, HD 19356 B, HIP 14576 B, HR 936 B
Physical characteristics:
- Mass: 0.770 x Sol
- Radius: 3.43 x Sol
- Temperature: 4,900 Kelvin
- Luminosity: 6.1 x Sol (bolometric)
- Spectral type: K0 IV
- Rotation period: 2.8 days
- Age: 570 million years
Inner binary orbitOrbital characteristics:
- Average separation: 0.0593 AU
- Orbital period: 2.867 days
CNames: Beta Persei C, 26 Persei C, GJ 9110 C, HD 19356 C, HIP 14576 C, HR 936 C
Physical characteristics:
- Mass: 1.58 x Sol
- Radius: 1.7 x Sol
- Temperature: 7,550 Kelvin
- Luminosity: 8.46 x Sol (bolometric)
- Spectral type: F1 V
- Rotation period: 6.89 days
- Age: 570 million years
Outer binary orbitOrbital characteristics:
- Average separation: 2.576 AU
- Orbital period: 1.862 years
- Eccentricity: 0.227

A star system in the constellation Perseus, around 90 light-years from Solsys. Algol was the first known eclipsing binary star, its nature determined by the deaf astronomer John Goodricke. The A and B stars together have a magnitude that regularly dips from 2.1 to 3.4 for a brief amount of time as seen from Earth, because the dimmer but larger B component passes in front of the A component with a period of 2.9 days. The stars form a so-called semidetached binary.

The A component is a bright B-type star; the B component is a K-type subgiant star. The B component has transferred much of its mass to the other star, and is much less massive than it would be otherwise. There is also a third component, an F-type star which orbits the pair at a mean distance of 2.6 astronomical units.

Algol produces a great deal of energy, and material from the accretion disk can be relatively easily extracted, making it one of the most resource rich systems in the inner Middle Regions. A number of NoCoZo corporations are based here, most notably the Algol Broadcasting Federation.
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Development Notes
Text by M. Alan Kazlev and Steve Bowers
Data Panel updated by The Astronomer, 2022
Initially published on 31 December 2001.