Discovery | |
---|---|
Discovered by | Marshall Johnson et al. [1] |
Discovery site | KELT |
Discovery date | 2018 |
Transit method | |
Orbital characteristics | |
0.05224 AU (7,815,000 km) | |
3.6127647 [1] d | |
Inclination | 86.46 [1] |
Star |
KELT-21 A (HD 332124) |
Physical characteristics | |
1.586 [1] RJ | |
Mass | <3.91 [1] MJ |
Mean
density | <1.24 g cm−3 |
Temperature | 2,051 K (1,778 °C; 3,232 °F) [1] |
KELT-21b is an extrasolar planet discovered in 2017. It is a hot Jupiter with radius of about 1.586 MJ. [1]
KELT-21b orbits KELT-21 A (HD 332124). It orbits the primary star in a triple
star system, with the other two stars located 1.2 arcseconds away. These two stars, designated KELT-21 B and C, have masses of 0.13 M☉ and 0.11 M☉, respectively.
[1] The primary star is heavy at 1.458±0.029M☉, extremely hot at 8210±771
K and rapidly rotating (equatorial velocity equal to 141 km/s).
[2] In comparison, the Sun has a temperature of 5772 K
[3] and rotates at an equatorial velocity of 1.997 km/s.
[4] The planetary orbit is well aligned with the equatorial plane of the host star, with misalignment equal to −5.6+1.7
−1.9°.
[5]
Transmission planetary spectroscopy was performed in 2021, based on a single transit observation in 2019. High planetary gravity and relatively low planetary temperature made detection of an atmosphere impossible that time. [6]
Discovery | |
---|---|
Discovered by | Marshall Johnson et al. [1] |
Discovery site | KELT |
Discovery date | 2018 |
Transit method | |
Orbital characteristics | |
0.05224 AU (7,815,000 km) | |
3.6127647 [1] d | |
Inclination | 86.46 [1] |
Star |
KELT-21 A (HD 332124) |
Physical characteristics | |
1.586 [1] RJ | |
Mass | <3.91 [1] MJ |
Mean
density | <1.24 g cm−3 |
Temperature | 2,051 K (1,778 °C; 3,232 °F) [1] |
KELT-21b is an extrasolar planet discovered in 2017. It is a hot Jupiter with radius of about 1.586 MJ. [1]
KELT-21b orbits KELT-21 A (HD 332124). It orbits the primary star in a triple
star system, with the other two stars located 1.2 arcseconds away. These two stars, designated KELT-21 B and C, have masses of 0.13 M☉ and 0.11 M☉, respectively.
[1] The primary star is heavy at 1.458±0.029M☉, extremely hot at 8210±771
K and rapidly rotating (equatorial velocity equal to 141 km/s).
[2] In comparison, the Sun has a temperature of 5772 K
[3] and rotates at an equatorial velocity of 1.997 km/s.
[4] The planetary orbit is well aligned with the equatorial plane of the host star, with misalignment equal to −5.6+1.7
−1.9°.
[5]
Transmission planetary spectroscopy was performed in 2021, based on a single transit observation in 2019. High planetary gravity and relatively low planetary temperature made detection of an atmosphere impossible that time. [6]