TRAPPIST-1g
Template:Planetbox begin Template:Planetbox image Template:Planetbox star Template:Planetbox orbit Template:Planetbox character Template:Planetbox discovery Template:Planetbox end TRAPPIST-1g, also designated as 2MASS J23062928-0502285 g, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1 39 light-years (12 parsecs) away from Earth in the constellation Aquarius. It was one of four new exoplanets to be discovered orbiting the star using observations from the Spitzer Space Telescope.[1] The exoplanet is within the habitable zone.[2] It was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.
Characteristics
Mass, radius, and temperature
TRAPPIST-1g is an Earth-sized exoplanet, meaning it has a mass and radius close to that of Earth. It has an equilibrium temperature of 198.6 K (−75 °C; −102 °F). This planet has a mass of 1.34 earth masses and a radius of 1.13 times earths radii, resulting in an estimated surface gravity of 10.3 m/s2 and a density of 5.13 g/cm3, both similar to Earth.
Host star
The planet orbits an (M-type) ultracool dwarf star named TRAPPIST-1. The star has a mass of 0.08 M☉ and a radius of 0.11 R☉. It has a temperature of 2550 K and is at least 500 million years old. In comparison, the Sun is 4.6 billion years old and has a temperature of 5778 K. The star is metal-rich, with a metallicity ([Fe/H]) of 0.04, or 109% the solar amount. This is particularly odd as such low-mass stars near the boundary between brown dwarfs and hydrogen-fusing stars should be expected to have considerably less metal content than the Sun. Its luminosity (L☉) is 0.05% of that of the Sun.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 18.8, too dim to be seen with the naked eye.
Orbit
TRAPPIST-1g orbits its host star with an orbital period of about 12.353 days and an orbital radius of about 0.045 times that of Earth's (compared to the distance of Mercury from the Sun, which is about 0.38 AU).
See also
References
- ^ "Temperate Earth-Sized Planets Found in Extraordinarily Rich Planetary System TRAPPIST-1". SpaceRef. 22 February 2017. Retrieved 11 February 2017.
- ^ "NASA telescope reveals largest batch of Earth-size, habitable-zone planets around single star". Exoplanet Exploration: Planets Beyond our Solar System (Press release). Retrieved 22 February 2017.
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