WASP-19

WASP-19, formally named Wattle,^[10] is a magnitude 12.3 star about 869 light-years (266 parsecs) away, located in the Vela constellation of the southern hemisphere.^[4] This star has been found to host a transiting hot Jupiter-type planet in a 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[4]
Apparent magnitude (B)	13.05[5]
Apparent magnitude (R)	12.12[5]
Apparent magnitude (I)	11.35[5]
Apparent magnitude (J)	10.911 ± 0.026[6]
Apparent magnitude (H)	10.602 ± 0.022[6]
Apparent magnitude (K)	10.481 ± 0.023[6]
B−V color index	1.3[citation needed]
V−R color index	0.1[citation needed]
R−I color index	0.82[citation needed]
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[citation needed]
Details[7]
Mass	0.965+0.091 −0.095 M☉
Radius	1.006+0.031 −0.034 R☉
Luminosity	0.905+0.071 −0.069 L☉
Surface gravity (log g)	4.417+0.020 −0.021 cgs
Temperature	5616+66 −65 K
Metallicity [Fe/H]	0.04+0.25 −0.30 dex
Rotation	11.76±0.09 d[8]
Rotational velocity (v sin i)	4.0 ± 1.0[9] km/s
Age	6.4+4.1 −3.5 Gyr
Other designations
Wattle, TOI-655, TIC 35516889, WASP-19, GSC 08181-01711, 2MASS J09534008-4539330, USNO-B1.0 0443-00193111[5]
Database references
SIMBAD	data
Exoplanet Archive	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.^[8]

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.^[11] 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 ^[12] 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.^[10]

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.^[4]

The WASP-19 planetary system^[7]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b / Banksia	1.154+0.078 −0.080 MJ	0.01652+0.00050 −0.00056	0.78883852(82)	0.0126+0.014 −0.0089	79.08+0.34 −0.37°	1.415+0.044 −0.048 RJ