WASP-19

WASP-19, formally named Wattle,^[8] is a magnitude 12.3 star about 869 light-years (266 parsecs) away, located in the Vela constellation of the southern hemisphere.^[9] This star has been found to host a transiting hot Jupiter-type planet in tight orbit.

WASP-19 / Wattle

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Vela[1]
Right ascension	09h 53m 40.07656s[2]
Declination	−45° 39′ 33.0572″[2]
Apparent magnitude (V)	12.312 ± 0.017[3]
Characteristics
Spectral type	G8V
Apparent magnitude (B)	13.58
Apparent magnitude (R)	12.17
Apparent magnitude (I)	11.35
Apparent magnitude (J)	10.911 ± 0.026[4]
Apparent magnitude (H)	10.602 ± 0.022[4]
Apparent magnitude (K)	10.481 ± 0.023[4]
B−V color index	1.3
V−R color index	0.1
R−I color index	0.82
Variable type	planetary transit
Astrometry
Radial velocity (Rv)	21.41±0.95[2] km/s
Proper motion (μ)	RA: −35.457 mas/yr[2] Dec.: 17.378 mas/yr[2]
Parallax (π)	3.7516±0.0090 mas[2]
Distance	869 ± 2 ly (266.6 ± 0.6 pc)
Absolute magnitude (MV)	5.3
Details[5]
Mass	0.97±0.02[6] M☉
Radius	0.885+0.086 −0.084 R☉
Luminosity	0.71 L☉
Surface gravity (log g)	4.45 ± 0.05[7] cgs
Temperature	5568 ± 71[7] K
Metallicity [Fe/H]	0.15 ± 0.07[7] dex
Rotation	11.76±0.09 d
Rotational velocity (v sin i)	4.0 ± 1.0[7] km/s
Age	9.95±2.49 Gyr
Other designations
Wattle, TOI-655, WASP-19, GSC 08181-01711, 2MASS J09534008-4539330, USNO-B1.0 0443-00193111
Database references
SIMBAD	data

WASP-19 is older than the Sun, has a fraction of heavy elements above the solar abundance, and is rotating rapidly, being spun up by the tides raised by the giant planet on a close orbit.^[5]

Nomenclature

The designation WASP-19 indicates that this was the 19th 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 were proposed by a team from Brandon Park Primary School in Wheelers Hill (Melbourne, Australia), led by scientist Lance Kelly and teacher David Maierhofer ^[11] and announced in June 2023. WASP-19 is named "Wattle" and its planet is named "Banksia", after the plant genera Wattle (specifically the golden wattle Acacia pycnantha) and Banksia (specifically the scarlet banksia Banksia coccinea) respectively.^[8]

Planetary system

In December 2009, the SuperWASP project announced that a hot Jupiter type exoplanet, WASP-19b, was orbiting very close to this star and with the shortest orbital period of any transiting exoplanet known at the time.^[9]

The WASP-19 planetary system^[12][6]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b / Banksia	1.168±0.023 MJ	0.01634 ± 0.00019	0.7888396 ± 0.00000010	0	78.76 ± 0.13°	1.18±0.12 RJ

See also

• List of extrasolar planets