Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Delphinus [1] |
Right ascension | 20h 24m 29.7235s [2] |
Declination | +16° 45′ 43.812″ [2] |
Apparent magnitude (V) | 11.94 [3] |
Characteristics | |
Evolutionary stage | main sequence [4] |
Spectral type | G0 [4] |
Apparent magnitude (J) | 11.103±0.022 [5] |
Apparent magnitude (H) | 10.846±0.022 [5] |
Apparent magnitude (K) | 10.791±0.020 [5] |
Variable type | Planetary transit [4] |
Astrometry | |
Radial velocity (Rv) | −16.67±0.88 [2] km/s |
Proper motion (μ) | RA: 13.325(11) mas/yr [2] Dec.: −5.505(11) mas/yr [2] |
Parallax (π) | 2.7358±0.0108 mas [2] |
Distance | 1,192 ± 5 ly (366 ± 1 pc) |
Details [4] | |
Mass | 1.13±0.035 M☉ |
Radius | 1.203±0.074 R☉ |
Luminosity | 1.58±0.23 L☉ |
Surface gravity (log g) | 4.33±0.05 cgs |
Temperature | 5905±80 K |
Metallicity | 0.15±0.04 |
Rotation | 7.015 d [6] |
Rotational velocity (v sin i) | 8.1±0.5 km/s |
Age | 4.0±1.0 Gyr |
Other designations | |
Moriah, TYC 1632-1396-1, GSC 01632-01396, 2MASS J20242972+1645437 [3] | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
HAT-P-23 is a G-type main-sequence star 1192 light-years away. It has a rapid rotation (rotation period equal to 7 days) for its advanced age of 4 billion years, and exhibits a strong starspot activity. [7] The star may be in the process of being spun up by the giant planet on close orbit. [8] The star is enriched in heavy elements, having about 140% amount of metals compared to solar abundance.
In 2019, the HAT-P-23 star has received a proper name Moriah and planet HAT-P-23b - Jebus at an international NameExoWorlds contest. [9] These names mean the ancient name of the mount at the center of Jerusalem city, and ancient (pre-Roman) name of Jerusalem itself, respectively.
In 2010 a transiting hot Jupiter like planet was detected. [4] It has a measured dayside temperature of 2154±90 K. [10] The planet is believed to be on an unstable orbit, and expected to be engulfed by its parent star about 7.5+2.9
−1.8 million years from now, [4] although timing measurements of multiple transits since the discovery have been unable to detect any reduction in the orbital period. [6] [11] The planetary orbit is probably aligned with the equatorial plane of the star, misalignment equal to 15±22°. [12] The color of planetary atmosphere is grey. [13] The atmosphere is mostly devoid of clouds, and shows tentatively a presence of Titanium(II) oxide. [14]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b (Jebus) | 2.09±0.111 MJ | 0.0232±0.0002 | 1.2128868±0.0000004 | 0.096 | 85.1±1.5° | 1.224±0.037 RJ |