WASP-8

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WASP-8
Artist's impression of an exoplanet in a retrograde orbit (without additional graphics).jpg
Artist's impression of a star like WASP-8
Observation data
Epoch J2000       Equinox J2000
Constellation Sculptor
Right ascension 23h 59m 36.07119s [1]
Declination −35° 01′ 52.9236″ [1]
Apparent magnitude  (V)9.87 [2]
Characteristics
WASP-8A
Evolutionary stage main-sequence
Spectral type G8V [3]
WASP-8B
Spectral type M [4]
Astrometry
Radial velocity (Rv)−1.38±0.26 [1]  km/s
Proper motion (μ)RA: 109.752  mas/yr [1]
Dec.: 7.615  mas/yr [1]
Parallax (π)11.1052 ± 0.0175  mas [1]
Distance 293.7 ± 0.5  ly
(90.0 ± 0.1  pc)
Position (relative to WASP-8A) [4]
ComponentWASP-8B
Epoch of observation 2016
Angular distance4.520±0.005 ″
Position angle 170.9±0.1°
Observed separation
(projected)		408 AU
Details [5]
WASP-8A
Mass 1.093±0.024  M☉
Radius 0.976±0.020  R☉
Luminosity 0.79  L☉
Surface gravity (log g)4.498±0.018  cgs
Temperature 5600±80  K
Metallicity [Fe/H]0.29±0.03  dex
Rotational velocity (v sin i)1.90±0.05 [6]  km/s
Age 0.3+0.9
−0.1  Gyr
WASP-8B
Mass 0.53±0.02  M☉
Temperature 3758+47
−43  K
Other designations
CD−35 16019, CPD−35 9465, SAO  214901, PPM  304426, WDS J23596-3502A, TOI-191, TIC  183532609, WASP-8, TYC  7522-505-1, 2MASS J23593607-3501530 [2]
Database references
SIMBAD A
B

WASP-8 is a binary star system 294 light-years (90 parsecs ) away. The star system is much younger than the Sun at 300 million to 1.2 billion years age, and is heavily enriched in heavy elements, having nearly twice the concentration of iron compared to the Sun. [5]

Contents

The primary, WASP-8A, is a magnitude 9.9 main-sequence yellow dwarf star. It is reported to be a G-type star with a temperature of 5600 K and has a mass 1.093±0.024, a radius 0.976±0.020 and a luminosity of 0.79 times that of the Sun. There is a companion star WASP-8B located 4.5 arcseconds away with the same proper motion, indicating a stellar binary system. [7] The binarity was confirmed in 2020. [4] The axis orientation of the primary star is uncertain, but it is close to pointing one of the poles to the Earth. [6]

Planetary system

The primary star is orbited by two known exoplanets, designated WASP-8b and WASP-8c. WASP-8b was discovered in 2010 by the astronomical transit method and was catalogued as part of the SuperWASP mission. [7] WASP-8c was discovered in late 2013 with the radial velocity method. [8]

The WASP-8 planetary system [5] [8]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 2.216±0.035  MJ 0.0817±0.00068.158715(16) [9] 0.3057±0.0046 [9] 88.51±0.09 ° 1.165±0.032  RJ
c≥9.45+2.26
−1.04  MJ 		5.28+0.63
−0.34		4323+740
−380		0——

See also

Related Research Articles

WASP-2 is a binary star system in the Delphinus constellation located about 500 light-years away. The primary is magnitude 12 orange dwarf star, orbited by red dwarf star on wide orbit. The star system shows an infrared excess noise of unknown origin.

WASP-6, also officially named Márohu, is a type-G yellow dwarf star located about 651 light-years away in the Aquarius constellation. Dim at magnitude 12, it is visible through a moderate sized amateur telescope. The star is about 80% of the size and mass of the Sun and it is a little cooler. Starspots in the WASP-6 system helped to refine the measurements of the mass and the radius of the planet WASP-6b.

<span class="mw-page-title-main">WASP-8b</span> Planet orbiting a star in a binary system in the constellation of Sculptor

WASP-8b is an exoplanet orbiting the star WASP-8A in the constellation of Sculptor. The star is similar to the Sun and forms a binary star with a red dwarf star (WASP-8B) of half the Sun's mass that orbits WASP-8A 4.5 arcseconds away. The system is 294 light-years away and is therefore located closer to Earth than many other star systems that are known to feature planets similar to WASP-8b. The planet and its parent star were discovered in the SuperWASP batch -6b to -15b. On 1 April 2008, Dr. Don Pollacco of Queen's University Belfast announced them at the RAS National Astronomy Meeting.

WASP-10 is a star in the constellation Pegasus. The SuperWASP project has observed and classified this star as a variable star, perhaps due to the eclipsing planet.

<span class="mw-page-title-main">WASP-4</span> G-type main sequence star in the constellation Phoenix

WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.

WASP-5 is a magnitude 12 G-type main-sequence star located about 1,020 light-years away in the Phoenix constellation. The star is likely older than the Sun, slightly enriched in heavy elements and is rotating rapidly, being spun up by the tides raised by the giant planet on a close orbit.

HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.

<span class="mw-page-title-main">WASP-21</span> Star in the constellation Pegasus

WASP-21 is a G-type star that is reaching the end of its main sequence lifetime approximately 850 light years from Earth in the constellation of Pegasus. The star is relatively metal-poor, having 40% of heavy elements compared to the Sun. Kinematically, WASP-21 belongs to the thick disk of the Milky Way. It has an exoplanet named WASP-21b.

WASP-46 is a G-type main-sequence star about 1,210 light-years away. The star is older than the Sun and is strongly depleted in heavy elements compared to the Sun, having just 45% of the solar abundance. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.

WASP-72 is the primary of a binary star system. It is an F7 class dwarf star, with an internal structure just on the verge of the Kraft break. It is orbited by a planet WASP-72b. The age of WASP-72 is younger than the Sun at 3.55±0.82 billion years.

BD+00 316 is an ordinary star with a close-orbiting planetary companion in the equatorial constellation of Cetus. It is also known as WASP-71 since 2019; BD+00 316 is the stellar identifier from the Bonner Durchmusterung catalogue. With an apparent visual magnitude of 10.56, it is too faint to be visible to the naked eye. This star is located at a distance of 1,160 light-years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 7.7 km/s.

WASP-59 is a K-type main-sequence star about 379 light-years away. The star's age is essentially unconstrained by observations. WASP-59 is slightly depleted in heavy elements, having 70% of the solar abundance of iron. The star produces extremely low levels of ultraviolet light, indicating an absence of flare activity.

WASP-57 is a single G-type main-sequence star about 1310 light-years away. WASP-57 is depleted in heavy elements, having 55% of the solar abundance of iron. WASP-57 is much younger than the Sun at 0.957±0.518 billion years.

WASP-54, also known as BD+00 3088, is a binary star system about 825 light-years away. The primary, WASP-54A, is a F-type main-sequence star, accompanied by the red dwarf WASP-54B on a wide orbit. WASP-54 is depleted in heavy elements, having 55% of the solar abundance of iron. The age of WASP-54 is slightly older than the Sun's at 6.9+1.0
−1.9 billion years.

WASP-52 is a K-type main-sequence star about 570 light-years away. It is older than the Sun at 10.7+1.9
−4.5 billion years, but it has a similar fraction of heavy elements. The star has prominent starspot activity, with 3% to 14% of the stellar surface covered by areas 575±150 K cooler than the rest of the photosphere.

WASP-69, also named Wouri, is a K-type main-sequence star 164 light-years away. Its surface temperature is 4782±15 K. WASP-69 is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.10±0.01, and is much younger than the Sun at 2 billion years. The data regarding starspot activity of WASP-69 are inconclusive, but spot coverage of the photosphere may be very high.

HAT-P-41 is a binary star system. Its primary is a F-type main-sequence star. Its surface temperature is 6390±100 K. compared to the Sun, HAT-P-41 is enriched in heavy elements, with a metallicity Fe/H index of 0.21±0.10, but is much younger at an age of 2.2±0.4 billion years.

WASP-88 is a F-type main-sequence star. Its surface temperature is 6450±61 K. WASP-88 is similar to the Sun in its concentration of heavy elements, with a metallicity Fe/H index of 0.03±0.04, and is younger at an age of 3.0±1.3 billion years.

WASP-84, also known as BD+02 2056, is a G-type main-sequence star 327 light-years away in the constellation Hydra. Its surface temperature is 5350±31 K and is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.05±0.02. It is rich in carbon and depleted of oxygen. WASP-84's age is probably older than the Sun at 8.5+4.1
−5.5 billion years. The star appears to have an anomalously small radius, which can be explained by the unusually high helium fraction or by it being very young.

WASP-80 is a K-type main-sequence star about 162 light-years away. The star's age is much younger than the Sun's at 1.352±0.222 billion years. WASP-80 is similar to the Sun in concentration of heavy elements, although this measurement is highly uncertain.

References

  1. 1 2 3 4 5 6 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.
  2. 1 2 "WASP-8". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 5 November 2023.
  3. ↑ Salz, M.; Schneider, P. C.; et al. (April 2015). "High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood". Astronomy & Astrophysics . 576: A42. arXiv: 1502.00576 . Bibcode:2015A&A...576A..42S. doi:10.1051/0004-6361/201425243.
  4. 1 2 3 Bohn, A. J.; Southworth, J.; Ginski, C.; Kenworthy, M. A.; Maxted, P. F. L.; Evans, D. F. (2020), "A multiplicity study of transiting exoplanet host stars", Astronomy & Astrophysics, 635: A73, arXiv: 2001.08224 , Bibcode:2020A&A...635A..73B, doi:10.1051/0004-6361/201937127, S2CID   210861118
  5. 1 2 3 Southworth, J.; Bohn, A. J.; Kenworthy, M. A.; Ginski, C.; Mancini, L. (2020), "A multiplicity study of transiting exoplanet host stars", Astronomy & Astrophysics, 635: A74, arXiv: 2001.08225 , Bibcode:2020A&A...635A..74S, doi:10.1051/0004-6361/201937334, S2CID   210860775
  6. 1 2 Bourrier, V.; Cegla, H. M.; et al. (March 2017). "Refined architecture of the WASP-8 system: A cautionary tale for traditional Rossiter-McLaughlin analysis". Astronomy & Astrophysics . 599. A33. arXiv: 1611.07985 . Bibcode:2017A&A...599A..33B. doi: 10.1051/0004-6361/201629973 . S2CID   118864447.
  7. 1 2 Queloz, D.; et al. (2010). "WASP-8b: a retrograde transiting planet in a multiple system". Astronomy and Astrophysics. 517. L1. arXiv: 1006.5089 . Bibcode:2010A&A...517L...1Q. doi:10.1051/0004-6361/201014768. S2CID   35774603.
  8. 1 2 Knutson, Heather A.; Fulton, Benjamin J.; Montet, Benjamin T.; Kao, Melodie; Ngo, Henry; Howard, Andrew W.; Crepp, Justin R.; Hinkley, Sasha; Bakos, Gaspar Á.; Batygin, Konstantin; Johnson, John Asher; Morton, Timothy D.; Muirhead, Philip S. (2013), "Friends of Hot Jupiters. I. A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets", The Astrophysical Journal, 785 (2): 126, arXiv: 1312.2954 , Bibcode:2014ApJ...785..126K, doi:10.1088/0004-637X/785/2/126, S2CID   42687848
  9. 1 2 Bonomo, A. S.; Desidera, S.; et al. (June 2017). "The GAPS Programme with HARPS-N at TNG. XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy & Astrophysics . 602: A107. arXiv: 1704.00373 . Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882.
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