WASP-26

WASP-26 is a yellow main sequence star in the constellation of Cetus.

WASP-26

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus[1]
Right ascension	00h 18m 24.7008s[2]
Declination	−15° 16′ 02.276″[2]
Apparent magnitude (V)	11.30[3]
Characteristics
Evolutionary stage	subgiant[4][2]
Spectral type	G0V[citation needed]
B−V color index	0.32
J−H color index	0.246
J−K color index	0.411
Astrometry
Radial velocity (Rv)	9.07±0.41[2] km/s
Proper motion (μ)	RA: +27.416[2] mas/yr Dec.: −24.524[2] mas/yr
Parallax (π)	3.9574±0.0247 mas[2]
Distance	824 ± 5 ly (253 ± 2 pc)
Details[5][6][7][8]
Mass	1.09±0.01 M☉
Radius	1.284±0.035 R☉
Luminosity	1.26 L☉
Surface gravity (log g)	4.40±0.01 cgs
Temperature	6015±55 K
Metallicity [Fe/H]	-0.02±0.09 dex
Rotational velocity (v sin i)	3.9±0.4 km/s
Age	6±2 Gyr
Other designations
WASP-26, TYC 5839-876-1, DENIS J001824.6-151601, 2MASS J00182469-1516022, Gaia DR2 2416782701664155008[9]
Database references
SIMBAD	data

Star characteristics

WASP-26 is an old star close to leaving the main sequence and is part of a wide binary. The binary's projected separation is 3800 astronomical units, its companion star being a red dwarf with an effective temperature of 4600K and a visual magnitude of 13.6.^[5] WASP-26 produces a large amount of ultraviolet light due to frequent flares, with an average ultraviolet flux close to the F7 class main-sequence star WASP-1.^[10]

Planetary system

The "Hot Jupiter" class planet WASP-26b was discovered around WASP-26 in 2010.^[5] The planet would have an equilibrium temperature of 1660±40 K, but measured temperatures are slightly higher at 1775K and no noticeable difference exists between the day-side and the night-side of the planet.^[11] A 2011 study using the Rossiter-McLaughlin effect failed to determine the inclination of the planetary orbit to the equatorial plane of the parent star due to high stellar noise,^[7] but an initial constraint of -34⁺³⁶
₋₂₆° was published in 2012.^[12]

The WASP-26 planetary system^[5][8]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.02±0.03 MJ	0.0400±0.0003	2.75660±0.00001	0	82.5±0.5°	1.216±0.047 RJ