WASP-4b

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WASP-4b
Exoplanet Comparison WASP-4 b.png
Size comparison of WASP-4b with Jupiter.
Discovery [1]
Discovered by Wide Angle Search for Planets
Discovery site South African Astronomical Observatory
Discovery dateOctober 31, 2007
Transit photometry
Orbital characteristics [2]
0.02239±0.00084  AU
Eccentricity <0.0033 [3]
1.338231587(22)  d
Inclination 88.02°±0.69°
Semi-amplitude 232.7+2.5
−2.2  m/s [3]
Star WASP-4
Physical characteristics [2]
1.312±0.045  RJ
Mass 1.164±0.082  MJ
Mean density
0.639±0.079  g/cm3
Temperature 1957±68  K (1,684 °C; 3,063 °F) [4]

    WASP-4b is an exoplanet, specifically a hot Jupiter, approximately 891 light-years away [5] in the constellation of Phoenix. [6]

    Contents

    Discovery

    The planet was the discovered by the Wide Angle Search for Planets team using images taken with the SuperWASP-South project's eight wide-angle cameras located at the South African Astronomical Observatory. [7] [8] [1] Analysis of over 4000 images taken between May and November 2006 resulted in the detection of a transit occurring every 1.3 days. Follow-up radial velocity observations using the Swiss 1.2-metre Leonhard Euler Telescope confirmed that the transiting object was a planet. [1]

    The radial velocity trend of WASP-4, caused by the presence of WASP-4 b. WASP-4 b rv.pdf
    The radial velocity trend of WASP-4, caused by the presence of WASP-4 b.

    Characteristics

    The planetary equilibrium temperature would be 1650±30 K, [9] but the measured dayside temperature is higher, with a 2015 study finding 1900±100 K [10] and a 2020 study finding 1957±68 K. [4]

    A study in 2012, utilizing the Rossiter–McLaughlin effect, determined the planetary orbit is probably aligned with the equatorial plane of the star, with misalignment equal to -1+14
    −12    °. [11]

    The planet's orbital period appears to be decreasing at a rate of 7.33±0.71 milliseconds per year, suggesting that its orbit is decaying, with a decay timescale of 15.77±1.57 million years. The anomalously high rate of orbital decay of WASP-4b is poorly understood as of 2021. [2]

    Related Research Articles

    <span class="mw-page-title-main">XO-3b</span> Extrasolar planet in the constellation Camelopardalis

    XO-3b is an exoplanet with about 11.79 times the mass of Jupiter, and it orbits its parent star XO-3 in about 3.2 days. The radius of this object is 1.217 times that of Jupiter. Astronomers announced their discovery on May 30, 2007, at the American Astronomical Society in Honolulu, Hawaii. Its discovery is attributed to the combined effort of amateur and professional astronomers working together on the XO Project using a telescope located on the Haleakala summit in Hawaii.

    <span class="mw-page-title-main">WASP-5b</span> Jovian size planet orbiting WASP-5

    WASP-5b is an exoplanet orbiting the star WASP-5 located approximately 1000 light-years away in the constellation Phoenix. The planet's mass and radius indicate that it is a gas giant with a similar bulk composition to Jupiter. The small orbital distance of WASP-5 b around its star means it belongs to a class of planets known as hot Jupiters. The planetary equilibrium temperature would be 1717 K, but the measured dayside temperature is higher, with a 2015 study finding 2500±100 K and a 2020 study finding 2000±90 K.

    <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.

    GSC 03089-00929 is a magnitude 12 star located approximately 757 light-years away in the constellation of Hercules. This star is a G type main sequence star that is similar to but slightly cooler than the Sun. This star is identified in SIMBAD as a variable star per the 1SWASP survey.

    WASP-18 is a magnitude 9 star located 400 light-years away in the Phoenix constellation of the southern hemisphere. It has a mass of 1.29 solar masses.

    <span class="mw-page-title-main">HAT-P-14b</span> Exoplanet in the constellation of Hercules

    HAT-P-14b, officially named Sissi also known as WASP-27b, is an extrasolar planet located approximately 224.2 ± 0.6 parsecs (731.2 ± 2.0 ly) away in the constellation of Hercules, orbiting the 10th magnitude F-type main-sequence star HAT-P-14. This planet was discovered in 2010 by the HATNet Project using the transit method. It was independently detected by the SuperWASP project.

    WASP-33b is an extrasolar planet orbiting the star HD 15082. It was the first planet discovered to orbit a Delta Scuti variable star. With a semimajor axis of 0.026 AU and a mass likely greater than Jupiter's, it belongs to the hot Jupiter class of planets.

    WASP-95 is a star 451 light-years away in the constellation Grus. With an apparent magnitude of 10.1, it is not visible to the naked eye. Its spectral type of G2 means it is a yellow sunlike star.

    KELT-18b is a hot Jupiter orbiting the F-type main sequence star KELT-18 approximately 1,058 light years away in the northern circumpolar constellation Ursa Major. The planet was discovered using the transit method, and was announced in June 2017.

    HAT-P-30, also known as WASP-51, is the primary of a binary star system about 700 light-years away. It is a G-type main-sequence star. HAT-P-30 has a similar concentration of heavy elements compared to the Sun.

    WASP-78, is a single F-type main-sequence star about 2350 light-years away. It is likely to be younger than the Sun at 3.4+1.5
    −0.8     billion years. WASP-78 is depleted in heavy elements, having a 45% concentration of iron compared to the Sun.

    BD-07 436, also known as WASP-77 since 2012, is a binary star system about 344 light-years away. The star's components appears to have a different age, with the secondary older than 9 billion years, while the primary's age is 5 billion years. The BD-07 436 system's concentration of heavy elements is similar to the Sun. Its stars display moderate chromospheric activity, including x-ray flares.

    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.

    WASP-63 or Kosjenka, also known as CD-38 2551, is a single star with an exoplanetary companion in the southern constellation of Columba. It is too faint to be visible with the naked eye, having an apparent visual magnitude of 11.1. The distance to this system is approximately 942 light-years based on parallax measurements, but it is drifting closer with a radial velocity of −24 km/s.

    L 98-59 is a bright M dwarf star, located in the constellation of Volans, at a distance of 10.608 parsecs, as measured by the Gaia spacecraft.

    References

    1. 1 2 3 Wilson, D. M.; et al. (2008). "WASP-4b: A 12th Magnitude Transiting Hot Jupiter in the Southern Hemisphere". The Astrophysical Journal Letters. 675 (2): L113–L116. arXiv: 0801.1509 . Bibcode: 2008ApJ...675L.113W . doi: 10.1086/586735 .
    2. 1 2 3 Turner, Jake D.; Flagg, Laura; Ridden-Harper, Andrew; Jayawardhana, Ray (2022), "Characterizing the WASP-4 System with TESS and Radial Velocity Data: Constraints on the Cause of the Hot Jupiter's Changing Orbit and Evidence of an Outer Planet", The Astronomical Journal, 163 (6): 281, arXiv: 2112.09621 , Bibcode:2022AJ....163..281T, doi: 10.3847/1538-3881/ac686f , S2CID   245329747
    3. 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. S2CID   118923163.
    4. 1 2 Wong, Ian; Shporer, Avi; Daylan, Tansu; Benneke, Björn; Fetherolf, Tara; Kane, Stephen R.; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Winn, Joshua N.; Jenkins, Jon M.; Boyd, Patricia T.; Glidden, Ana; Goeke, Robert F.; Sha, Lizhou; Ting, Eric B.; Yahalomi, Daniel (2020), "Systematic Phase Curve Study of Known Transiting Systems from Year One of the TESS Mission", The Astronomical Journal, 160 (4): 155, arXiv: 2003.06407 , Bibcode:2020AJ....160..155W, doi: 10.3847/1538-3881/ababad , S2CID   212717799
    5. ↑ 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.
    6. ↑ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode: 1987PASP...99..695R . doi: 10.1086/132034 . Vizier query form
    7. ↑ Sherriff, Lucy (2007-10-31). "UK boffins ID three new exo-planets". The Register. Retrieved 2018-09-23.
    8. ↑ "Astronomer discovers new planets". BBC News. 2007-10-31. Retrieved 2018-09-23.
    9. ↑ Table 3, Improved parameters for the transiting hot Jupiters WASP-4b and WASP-5b, M. Gillon et al., Astronomy and Astrophysics496, #1 (2009), pp. 259–267, doi:10.1051/0004-6361:200810929, Bibcode:2009A&A...496..259G.
    10. ↑ Zhou, G.; Bayliss, D. D. R.; Kedziora-Chudczer, L.; Tinney, C. G.; Bailey, J.; Salter, G.; Rodriguez, J. (2015). "Secondary eclipse observations for seven hot-Jupiters from the Anglo-Australian Telescope". Monthly Notices of the Royal Astronomical Society. 454 (3): 3002–3019. arXiv: 1509.04147 . Bibcode:2015MNRAS.454.3002Z. doi: 10.1093/mnras/stv2138 .
    11. ↑ Albrecht, Simon; Winn, Joshua N.; Johnson, John A.; Howard, Andrew W.; Marcy, Geoffrey W.; Butler, R. Paul; Arriagada, Pamela; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Hirano, Teruyuki; Bakos, Gaspar; Hartman, Joel D. (2012), "Obliquities of Hot Jupiter Host Stars: Evidence for Tidal Interactions and Primordial Misalignments", The Astrophysical Journal, 757 (1): 18, arXiv: 1206.6105 , Bibcode:2012ApJ...757...18A, doi:10.1088/0004-637X/757/1/18, S2CID   17174530

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