Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Puppis [1] |
Right ascension | 07h 10m 24.06046s [2] |
Declination | −39° 05′ 50.5712″ [2] |
Apparent magnitude (V) | 10.4 |
Characteristics | |
Evolutionary stage | main sequence [2] |
Spectral type | F6V [3] [4] |
Apparent magnitude (B) | 11.00 [5] |
Apparent magnitude (V) | 10.51 [5] |
Apparent magnitude (J) | 9.625 [5] |
Apparent magnitude (H) | 9.439 [5] |
Apparent magnitude (K) | 9.374 [5] |
Astrometry | |
Radial velocity (Rv) | 38.25±0.22 [2] km/s |
Proper motion (μ) | RA: −3.735 mas/yr [2] Dec.: 25.663 mas/yr [2] |
Parallax (π) | 3.7996±0.0104 mas [2] |
Distance | 858 ± 2 ly (263.2 ± 0.7 pc) |
Details [6] | |
Mass | 1.330±0.019 M☉ |
Radius | 1.461±0.015 R☉ |
Surface gravity (log g) | 4.251±0.003 cgs |
Temperature | 6,628±66 K |
Metallicity [Fe/H] | +0.17±0.05 dex |
Rotational velocity (v sin i) | 11.90±0.31 [7] km/s |
Age | 1.11±0.14 Gyr |
Other designations | |
Dilmun, CD−38 3220, TOI-495, WASP-121, TYC 7630-352-1, 2MASS J07102406-3905506 [5] | |
Database references | |
SIMBAD | data |
WASP-121, also known as CD-38 3220 and formally named Dilmun, [8] is a magnitude 10.4 star located approximately 858 light-years (263 parsecs ) away in the constellation Puppis. [1] WASP-121 has a mass and radius similar to the Sun's. It hosts one known exoplanet.
The star, although metal-rich in terms of overall contents of heavy elements, is depleted of carbon. The carbon to oxygen molar ratio of 0.23±0.05 for WASP-121 is well below the solar ratio of 0.55. [9]
The designation WASP-121 indicates that this was the 121st star found to have a planet by the Wide Angle Search for Planets.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project. [10] The approved names, proposed by a team from Bahrain, were announced in June 2023. WASP-121 is named Dilmun after the ancient civilization, and its planet is named Tylos after the ancient Greek name for Bahrain. [11]
In 2015, the exoplanet WASP-121b was discovered orbiting WASP-121 by the transit method. [3] [12] WASP-121b is a hot Jupiter with a mass about 1.18 times that of Jupiter and a radius about 1.81 times that of Jupiter. [4] [13] The exoplanet orbits WASP-121, its host star, every 1.27 days. [4] [13] Hot water molecules have been found in the stratosphere of WASP-121b (i.e., the atmospheric layer in which temperatures increase as the altitude increases). [3] [13] [14] [15]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b / Tylos | 1.170±0.043 MJ | 0.02571±0.00010 | 1.275 [3] | 0.0 [3] | 87.6 [3] ° | 1.742±0.006 RJ |