Discovery [1] | |
---|---|
Discovered by | Geoffrey W. Marcy et al. |
Discovery date | February 2014 (announced) |
Transit method | |
Designations | |
KIC 3544595 b, KOI-69.01, BD+38 3583b, TYC 3134-218-1 b [2] | |
Orbital characteristics [3] | |
0.05343±0.00065 AU | |
Eccentricity | 0 |
4.72673978(97) d | |
Inclination | 89.183°±0.044° |
Semi-amplitude | 1.89±0.21 m/s |
Star | Kepler-93 |
Physical characteristics [3] | |
1.478±0.019 R🜨 | |
Mass | 4.66±0.53 M🜨 |
Mean
density | 7.93+0.96 −0.94 g/cm3 |
Temperature | 1133±17 K (860 °C; 1,580 °F, equilibrium) |
Kepler-93b (KOI-69b) is a hot, dense transiting Super-Earth exoplanet located approximately 313 light-years (96 parsecs) [4] away in the constellation of Lyra, [5] [6] orbiting the G-type star [5] Kepler-93. Its discovery was announced in February 2014 by American astronomer Geoffrey Marcy and his team. [1] In July 2014, its radius was determined with a mere 1.3% margin of error, the most precise measurement ever made for an exoplanet's radius at the time. [7]
The planet has a radius of around 1.478
R🜨 (9,416
km), with an uncertainty of just 0.019
R🜨 (121 km),
[8] making it the most precisely measured exoplanet ever in terms of radius as of July 2014.
[7] The planet is substantially denser than
Earth at 6.88±1.18 g/cm3
[9] thanks to its high mass of roughly 4
ME, consistent with a rocky composition of
iron and
magnesium silicate.
[9] In 2023, the planet's mass was revised upward to 4.66±0.53 ME, placing its density at 7.93+0.96
−0.94 g/cm3,
[3] roughly the same as the metal
iron (7.874
g/cm3).
[10]
Based on these findings, the interior of the planet is likely similar to that of Earth and Venus, with an iron core making up around 26% of its total mass (albeit with a large uncertainty of ±20%), [11] compared to the 32.5 ± 0.1% of Earth and 31 ± 1% of Venus. [11]
The planet orbits its host star every 4.73 days [8] at a distance of 0.05343 AU (7,993,000 km), [3] less than one-seventh the radius of Mercury's orbit. Its equilibrium temperature is approximately 1,133 K (860 °C; 1,580 °F), [3] which is as hot as lava and well above the melting point of aluminium. [a]
The planet orbits a Sun-like ( spectral type G5V) [5] star named Kepler-93. The star has a mass of 0.911 M☉ and a radius of 0.919 R☉. It has a temperature of 5,669 K (5,396 °C; 9,745 °F) and is 6.6 billion years old. [8] In comparison, the Sun is 4.6 billion years old, [14] has a temperature of 5,772 K (5,499 °C; 9,930 °F) and a spectral type of G2V. [15] The apparent magnitude of the star is 9.931, [9] making it too dim to be visible from Earth by the naked eye. [16]
The star is host to an additional non-transiting confirmed companion, Kepler-93c, which was discovered using the radial-velocity method and announced in 2014, concurrently with Kepler-93b. [1] The object is most likely a brown dwarf orbiting much farther out than Kepler-93b, though its precise nature remains uncertain. The discovery paper reported a lower limit on the mass of 3 MJ and a minimal orbital period of 1,460 days (4.0 years), [1] while a subsequent study in 2015 weighed the planet at >8.5 MJ and presented an orbital period of >10 years, placing its orbit beyond 4.5 AU from the star, [9] and a 2023 study increased these lower limits further, to a mass >21 MJ, an orbital period >48.6 years, and a semi-major axis >13 AU. [3]
Discovery [1] | |
---|---|
Discovered by | Geoffrey W. Marcy et al. |
Discovery date | February 2014 (announced) |
Transit method | |
Designations | |
KIC 3544595 b, KOI-69.01, BD+38 3583b, TYC 3134-218-1 b [2] | |
Orbital characteristics [3] | |
0.05343±0.00065 AU | |
Eccentricity | 0 |
4.72673978(97) d | |
Inclination | 89.183°±0.044° |
Semi-amplitude | 1.89±0.21 m/s |
Star | Kepler-93 |
Physical characteristics [3] | |
1.478±0.019 R🜨 | |
Mass | 4.66±0.53 M🜨 |
Mean
density | 7.93+0.96 −0.94 g/cm3 |
Temperature | 1133±17 K (860 °C; 1,580 °F, equilibrium) |
Kepler-93b (KOI-69b) is a hot, dense transiting Super-Earth exoplanet located approximately 313 light-years (96 parsecs) [4] away in the constellation of Lyra, [5] [6] orbiting the G-type star [5] Kepler-93. Its discovery was announced in February 2014 by American astronomer Geoffrey Marcy and his team. [1] In July 2014, its radius was determined with a mere 1.3% margin of error, the most precise measurement ever made for an exoplanet's radius at the time. [7]
The planet has a radius of around 1.478
R🜨 (9,416
km), with an uncertainty of just 0.019
R🜨 (121 km),
[8] making it the most precisely measured exoplanet ever in terms of radius as of July 2014.
[7] The planet is substantially denser than
Earth at 6.88±1.18 g/cm3
[9] thanks to its high mass of roughly 4
ME, consistent with a rocky composition of
iron and
magnesium silicate.
[9] In 2023, the planet's mass was revised upward to 4.66±0.53 ME, placing its density at 7.93+0.96
−0.94 g/cm3,
[3] roughly the same as the metal
iron (7.874
g/cm3).
[10]
Based on these findings, the interior of the planet is likely similar to that of Earth and Venus, with an iron core making up around 26% of its total mass (albeit with a large uncertainty of ±20%), [11] compared to the 32.5 ± 0.1% of Earth and 31 ± 1% of Venus. [11]
The planet orbits its host star every 4.73 days [8] at a distance of 0.05343 AU (7,993,000 km), [3] less than one-seventh the radius of Mercury's orbit. Its equilibrium temperature is approximately 1,133 K (860 °C; 1,580 °F), [3] which is as hot as lava and well above the melting point of aluminium. [a]
The planet orbits a Sun-like ( spectral type G5V) [5] star named Kepler-93. The star has a mass of 0.911 M☉ and a radius of 0.919 R☉. It has a temperature of 5,669 K (5,396 °C; 9,745 °F) and is 6.6 billion years old. [8] In comparison, the Sun is 4.6 billion years old, [14] has a temperature of 5,772 K (5,499 °C; 9,930 °F) and a spectral type of G2V. [15] The apparent magnitude of the star is 9.931, [9] making it too dim to be visible from Earth by the naked eye. [16]
The star is host to an additional non-transiting confirmed companion, Kepler-93c, which was discovered using the radial-velocity method and announced in 2014, concurrently with Kepler-93b. [1] The object is most likely a brown dwarf orbiting much farther out than Kepler-93b, though its precise nature remains uncertain. The discovery paper reported a lower limit on the mass of 3 MJ and a minimal orbital period of 1,460 days (4.0 years), [1] while a subsequent study in 2015 weighed the planet at >8.5 MJ and presented an orbital period of >10 years, placing its orbit beyond 4.5 AU from the star, [9] and a 2023 study increased these lower limits further, to a mass >21 MJ, an orbital period >48.6 years, and a semi-major axis >13 AU. [3]