WASP-17

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WASP-17 / Dìwö
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Scorpius
Right ascension 15h 59m 50.9492s[1]
Declination −28° 03′ 42.313″[1]
Apparent magnitude (V) 11.500[2]
Characteristics
Spectral type F6V
Astrometry
Proper motion (μ) RA: −8.263(29) mas/yr[1]
Dec.: −9.427(22) mas/yr[1]
Parallax (π)2.4811 ± 0.0255 mas[1]
Distance1,310 ± 10 ly
(403 ± 4 pc)
Details
Mass1.2 M
Radius1.38 R
Surface gravity (log g)4.14 ± 0.03[3] cgs
Temperature6509 ± 86[3] K
Metallicity [Fe/H]–0.02 ± 0.09[3] dex
Rotational velocity (v sin i)10.6 ± 1.3[3] km/s
AgeGyr
Other designations
Dìwö, 1SWASP J155950.94−280342.3,
USNO-B1.0 0619-0419495,
2MASS J15595095-2803422,
TYC2 6787-1927-1, Gaia DR2 6042793005779654656
Database references
SIMBADdata
Exoplanet Archivedata

WASP-17 is an F-type main sequence star approximately 1,310 light-years away in the constellation Scorpius.[4][1][5]

WASP-17 is named Dìwö. The name was selected in the NameExoWorlds campaign by Costa Rica, during the 100th anniversary of the IAU. Dìwö in Bribri language means the sun.[6][7]

The star, although similar to Sun in terms of overall contents of heavy elements, is depleted of carbon. Carbon to oxygen molar ratio of 0.18±0.04 for WASP-17 is well below solar ratio of 0.55.[8]

Planetary system[edit]

As of 2009, an extrasolar planet has been confirmed to orbit the star. The star is unusual in that it has an orbiting exoplanet, WASP-17b,[9][10] which is believed to orbit in the opposite direction to the star's spin and is said to be twice the size of Jupiter, but half its mass. The planet is also named Ditsö̀. It is subject to intensive photo-evaporation, and may be completely destroyed within one billion years from now.[11]

The planet was discovered by the SuperWASP project, hence the name.

The WASP-17 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b / Ditsö̀ 0.486 (± 0.032) MJ 0.0515 (± 0.00034) 3.735438 (± 6.8e-06) 0.028 +0.018
−0.015

References[edit]

  1. ^ a b c d e 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. ^ Maxted, P. F. L.; et al. (2011). "UBV(RI)C photometry of transiting planet hosting stars". Monthly Notices of the Royal Astronomical Society. 418 (2): 1039–1042. arXiv:1108.0349. Bibcode:2011MNRAS.418.1039M. doi:10.1111/j.1365-2966.2011.19554.x. S2CID 117056033.
  3. ^ a b c d Torres, Guillermo; et al. (2012). "Improved Spectroscopic Parameters for Transiting Planet Hosts". The Astrophysical Journal. 757 (2). 161. arXiv:1208.1268. Bibcode:2012ApJ...757..161T. doi:10.1088/0004-637X/757/2/161. S2CID 16580774.
  4. ^ Anderson, D. R.; et al. (2010). "WASP-17b: An Ultra-Low Density Planet in a Probable Retrograde Orbit". The Astrophysical Journal. 709 (1): 159–167. arXiv:0908.1553. Bibcode:2010ApJ...709..159A. doi:10.1088/0004-637X/709/1/159. S2CID 53628741.
  5. ^ "Newfound Planet Orbits Backward". Space.com. 12 August 2009.
  6. ^ "Approved names". NameExoworlds. Retrieved 2020-01-02.
  7. ^ "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
  8. ^ Polanski, Alex S.; Crossfield, Ian J. M.; Howard, Andrew W.; Isaacson, Howard; Rice, Malena (2022), Chemical Abundances for 25 JWST Exoplanet Host Stars with KeckSpec, arXiv:2207.13662
  9. ^ "New exoplanet orbits 'backwards'". August 12, 2009 – via news.bbc.co.uk.
  10. ^ "New-found Planet Orbits Backward".
  11. ^ D. Ehrenreich and J.-M. Désert, "Mass-loss rates for transiting exoplanets", 2011