Gliese 777
Binary star system with three confirmed exoplanets.
Last updated
Gliese 777, also known as HD 190360, is a binary star system roughly 52 light-years away in Cygnus. Its primary star hosts three confirmed exoplanets, making it a notable system for planetary studies.
Quick Facts
- Distance
- 52 light-years (15.9 parsecs)
- Constellation
- Cygnus
- Primary star age
- 4.79 billion years
- Primary star mass
- 4% less massive than the Sun
- Primary star metallicity
- 70% more metals than the Sun
- Number of confirmed planets
- 3
- First planet discovered
- 2002
Facts from the source article.
Stellar components
The primary, Gliese 777 A, is a yellow subgiant older than the Sun at 4.79 billion years. It is 4% less massive than the Sun and has about 70% more metals. The secondary, Gliese 777 B, is a dim red dwarf orbiting at roughly 3,000 astronomical units. A faint additional companion has been reported but not confirmed.
Planetary system
In 2002, the Geneva team announced Gliese 777 Ab, a long-period planet initially thought to be a Jupiter twin but later found to have an eccentric orbit (e=0.36) and a mass at least 1.5 times Jupiter's; its true mass was measured via astrometry in 2021. A second planet, Gliese 777 Ac, was detected in 2005 with a 17.1-day period and a mass about 18 times Earth's, similar to Neptune; its orbit was later found to be eccentric. A third candidate with an 89-day period was presented in 2025 and confirmed in 2026. A METI message, Cosmic Call 1, was sent to the system on July 1, 1999, and will arrive in April 2051.
More in Planetary Systems with Three Confirmed Planets
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Gliese 777 (CC BY-SA 4.0).
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