HATS-70

HATS-70

Observation data Epoch J2000        Equinox J2000
Constellation	Canis Major [1]
Right ascension	07h 16m 25.08800s [2]
Declination	−31° 14′ 39.8583″ [2]
Apparent magnitude  (V)	12.23 [3]
Characteristics
Evolutionary stage	main sequence [2]
Spectral type	A [4]
Astrometry
Proper motion (μ)	RA: -2.396 mas/yr [2] Dec.: +2.443 mas/yr [2]
Parallax (π)	0.7504±0.0133  mas [2]
Distance	4,350 ± 80  ly (1,330 ± 20  pc)
Details [4]
Mass	1.78±0.12  M☉
Radius	1.881+0.059 −0.066  R☉
Luminosity	12.0+5.5 −3.4  L☉
Surface gravity (log g)	4.167+0.044 −0.036  cgs
Temperature	7,930+630 −820  K
Metallicity [Fe/H]	0.041+0.095 −0.107  dex
Rotational velocity (v sin i)	40.61+0.32 −0.35 km/s
Age	0.81+0.50 −0.33  Gyr
Other designations
HATS-70, TOI-1916, TIC 98545929, TYC 7103-114-1, 2MASS J07162509-3114397 [3]
Database references
SIMBAD	data
Exoplanet Archive	data

HATS-70 is a single star in the constellation of Canis Major at a distance of approximately 4,350 light-years (1,330 parsecs ) from the Sun. The apparent magnitude of the star is +12.23, meaning it is much too faint to be visible to the naked eye. The age of the star is about 810 million years and it has one planet in its orbit.

Characteristics

HATS-70 is an A-type main-sequence star, with a mass 1.78 times larger than the Sun's mass, 1.88 times the radius, and 12 times the luminosity. It has an effective temperature of 7,930 K (7,660 °C; 13,810 °F). It is a rapidly rotating star with measurable oblateness. ^[4]

Planetary system

In 2018, a group of astronomers working as part of the HATSouth project announced the discovery of a massive planet or brown dwarf around this star, HATS-70b. This object's mass is close to the deuterium fusion limit, and the discovery paper refers to it as a brown dwarf. It is in a close orbit with a period of less than two days, with an obliquity of 13.2°+6.4°
−5.9° (or 160.4°+5.4°
−5.2°) to the star's equator. ^[4]

The HATS-70 planetary system ^[4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	12.9+1.8 −1.6  MJ	0.03632+0.00074 −0.00087	1.8882378(15)	<0.18	86.7+1.6 −1.9 °	1.384+0.079 −0.074  RJ

References

1. Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific . 99 (617): 695. Bibcode:1987PASP...99..695R. doi: 10.1086/132034 . Constellation record for this object at VizieR.
2. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
3. "HATS-70". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 13 September 2025.
4. Zhou, G.; Bakos, G. Á.; et al. (January 2019). "HATS-70b: A 13 MJ Brown Dwarf Transiting an A Star". The Astronomical Journal . 157 (1): 31. arXiv: 1811.06925 . Bibcode:2019AJ....157...31Z. doi: 10.3847/1538-3881/aaf1bb .