WASP-12b

Last updated

WASP-12b
Exoplanet Comparison WASP-12 b.png
Size comparison of WASP-12b (right) with Jupiter
Discovery
Discovered by Cameron et al. (SuperWASP)
Discovery site SAAO
Discovery dateApril 2008 [1]
Transit
Orbital characteristics
0.0234+0.00056
−0.00050 AU
Eccentricity 0.049 ± 0.015
1.0914199±0.0000002  d [2]
Inclination 81.92°±1.51° [2]
−74°+13°
−10°
Star WASP-12
Physical characteristics
1.937±0.056 [3] RJ
Mass 1.47+0.076
−0.069 [4] MJ
Mean density
0.266  g/cm3 [4]
3.004±0.015 g [4]
Temperature 3128+64
−68 K (2885+64
−68 °C, 5225+147
−155 °F) [5]

    WASP-12b is a hot Jupiter [6] (a class of extrasolar planets) orbiting the star WASP-12, discovered in April of 2008, by the SuperWASP planetary transit survey. [7] [1] The planet takes only a little over one Earth day to orbit its star, in contrast to about 365.25 days for the Earth to orbit the Sun. Its distance from the star (approximately 3.5 million kilometers [2.2 million miles ; 0.023 astronomical units ]) is only the Earth's distance from the Sun, with an eccentricity the same as Jupiter's. Consequently, it has one of the lowest densities for exoplanets ("inflated" by the flux of energy from the star). On December 3, 2013, scientists working with the Hubble Space Telescope (HST) reported detecting water in the atmosphere of the exoplanet. [8] [9] In July 2014, NASA announced finding very dry atmospheres on three exoplanets (HD 189733b, HD 209458b, WASP-12b) orbiting sun-like stars. [10]

    Contents

    In September 2017, researchers working on the HST announced that WASP-12b reflects just 6% of the light that shines on its surface. As a result, the exoplanet has been described as "black as asphalt" and as "pitch black." [11]

    Characteristics

    Artist's depiction of WASP-12b's atmosphere being tidally stripped by its parent star The Pitch-Black Exoplanet WASP-12b.jpg
    Artist's depiction of WASP-12b's atmosphere being tidally stripped by its parent star

    Since hot Jupiter exoplanets are tidally locked (i. e. the same side always faces the host star, just as the same side of the Moon always faces the Earth), there is a large flow of heat from the highly irradiated illuminated side to the cooler dark side. This is thought to result in strong winds rushing around the planet's atmosphere.

    Taylor Bell and Nicolas Cowan have pointed out that hydrogen will tend to be ionised on the day side. After flowing to the cooler face in a wind, it will then tend to recombine into neutral atoms, and thus will enhance the transport of heat.

    The planet is so close to its star that its tidal forces are distorting it into an egg shape and pulling away its atmosphere at a rate of about 10−7 MJ (about 189 quadrillion tons) per year. [12] The so-called "tidal heating", and the proximity of the planet to its star, combine to bring the surface temperature to more than 2,500 K (2,200 °C).

    On May 20, 2010, the Hubble Space Telescope spotted WASP-12b being "consumed" by its star. Scientists had been aware that stars could consume planets; however, this was the first time such an event had been observed so clearly. It has been estimated that the planet has between 3 and 10 million years left of its life. [13] [14] [15]

    The Hubble Space Telescope observed the planet by using its Cosmic Origins Spectrograph (COS). The observations have confirmed predictions published in Nature in February 2009 by Peking University's Shu-lin Li. The planet's atmosphere has ballooned to be nearly three times the radius of Jupiter, while the planet itself has 40% more mass than Jupiter.

    Orbit

    A study in 2012, utilizing the Rossiter–McLaughlin effect, determined that WASP-12b's orbit is strongly misaligned with the equatorial plane of its star by 59+15
    −20    °. [16]

    A study from 2019 found that the time interval between two transits has decreased by 29 ± 2 msec/year since the discovery in 2008. The value was updated in 2020 to 32.53±1.62 msec/year, giving WASP-12b an estimated lifetime of 2.90±0.14 million years. [14] The study came to the conclusion that the orbit of WASP-12b is decaying as a result of tidal interactions between the planet and the host star WASP-12. Due to this decay, the orbital period will get shorter and the planet will get closer to the host star, until it will become part of the star. The decay is much faster than the decay of WASP-19b, which does not show a decay with current data. [17] [18] In 2022, the decay rate was further refined to 29.81±0.94 msec/year, which corresponds to an estimated lifetime of 3.16±0.10  Ma . [15]

    Carbon content

    Evidence reported in a 2010 study indicates that WASP-12b has an enhanced carbon-to-oxygen ratio, significantly higher than that of the Sun, indicating that it is a carbon-rich gas giant. The C/O ratio compatible with observations is about 1, while the solar value is 0.54. The C/O ratios suggest that carbon-rich planets may have formed in the star system. [19] One of the researchers behind that study commented that "with more carbon than oxygen, you would get rocks of pure carbon, such as diamond or graphite". [20]

    The published study states, "Although carbon-rich giant planets like WASP-12b have not been observed, theory predicts myriad compositions for carbon-dominated solid planets. Terrestrial-sized carbon planets, for instance, could be dominated by graphite or diamond interiors, as opposed to the silicate composition of Earth." [19] These remarks have led the media to pick up on the story, [21] some even calling WASP-12b a "diamond planet". [22]

    The carbon content of the planet is located within its atmosphere, in the form of carbon monoxide and methane. The study appears in the journal Nature . [23]

    Comparison of "hot Jupiter" exoplanets - from top left to lower right: WASP-12b, WASP-6b, WASP-31b, WASP-39b, HD 189733b, HAT-P-12b, WASP-17b, WASP-19b, HAT-P-1b and HD 209458b. Clear to cloudy hot Jupiters.jpg
    Comparison of "hot Jupiter" exoplanets - from top left to lower right: WASP-12b, WASP-6b, WASP-31b, WASP-39b, HD 189733b, HAT-P-12b, WASP-17b, WASP-19b, HAT-P-1b and HD 209458b.

    Candidate satellite

    Russian astronomers studying a curve of change of shine of the planet observed regular variation of light that may arise from plasma torus surrounding at least one exomoon in orbit around WASP-12b. [24] This is not expected, as hot Jupiter-type planets are expected to lose large moons within geologically short timescales. [25] The satellite in question could instead be a Trojan body. [26]

    See also

    Related Research Articles

    <span class="mw-page-title-main">Hot Jupiter</span> Class of high-mass planets orbiting close to a star

    Hot Jupiters are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods. The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters".

    <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">HD 189733 b</span> Hot Jupiter exoplanet in the constellation Vulpecula

    HD 189733 b is an exoplanet in the constellation of Vulpecula approximately 64.5 light-years away from the Solar System. Astronomers in France discovered the planet orbiting the star HD 189733 on October 5, 2005, by observing its transit across the star's face. With a mass 11.2% higher than that of Jupiter and a radius 11.4% greater, HD 189733 b orbits its host star once every 2.2 days at an orbital speed of 152.0 kilometers per second, making it a hot Jupiter with poor prospects for extraterrestrial life.

    <span class="mw-page-title-main">WASP-4b</span> Extrasolar planet in the constellation Phoenix

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

    <span class="mw-page-title-main">WASP-17b</span> Hot-Jupiter exoplanet in the orbit of the star WASP-17

    WASP-17b, officially named Ditsö̀, is an exoplanet in the constellation Scorpius that is orbiting the star WASP-17. Its discovery was announced on 11 August 2009. It is the first planet discovered to have a retrograde orbit, meaning it orbits in a direction counter to the rotation of its host star. This discovery challenged traditional planetary formation theory. In terms of diameter, WASP-17b is one of the largest exoplanets discovered and at half Jupiter's mass, this made it the most puffy planet known in 2010. On 3 December 2013, scientists working with the Hubble Space Telescope reported detecting water in the exoplanet's atmosphere.

    <span class="mw-page-title-main">WASP-18b</span> Extrasolar planet that has an orbital period of less than one day

    WASP-18b is an exoplanet that is notable for having an orbital period of less than one day. It has a mass equal to 10 Jupiter masses, just below the boundary line between planets and brown dwarfs. Due to tidal deceleration, it is expected to spiral toward and eventually merge with its host star, WASP-18, in less than a million years. The planet is approximately 3.1 million km from its star, which is about 400 light-years from Earth. A team led by Coel Hellier, a professor of astrophysics at Keele University in England, discovered the exoplanet in 2009.

    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">WASP-19b</span> Extrasolar planet in the constellation Vela

    WASP-19b, formally named Banksia, is an exoplanet, notable for possessing one of the shortest orbital periods of any known planetary body: 0.79 days or approximately 18.932 hours. It has a mass close to that of Jupiter, but by comparison has a much larger radius ; making it nearly the size of a low-mass star. It orbits the star WASP-19 in the Vela constellation. At the time of discovery it was the shortest period hot Jupiter discovered as planets with shorter orbital periods had a rocky, or metallic composition.

    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.

    <span class="mw-page-title-main">WASP-43b</span> Extrasolar planet in the constellation Sextans

    WASP-43b, formally named Astrolábos, is a transiting planet in orbit around the young, active, and low-mass star WASP-43 in the constellation Sextans. The planet is a hot Jupiter with a mass twice that of Jupiter, but with a roughly equal radius. WASP-43b was flagged as a candidate by the SuperWASP program, before they conducted follow-ups using instruments at La Silla Observatory in Chile, which confirmed its existence and provided orbital and physical characteristics. The planet's discovery was published on April 14, 2011.

    <span class="mw-page-title-main">WASP-121b</span> Hot Jupiter exoplanet orbiting WASP-121

    WASP-121b, formally named Tylos, is an exoplanet orbiting the star WASP-121. WASP-121b is the first exoplanet found to contain water in an extrasolar planetary stratosphere. WASP-121b is in the constellation Puppis, and is about 858 light-years from Earth.

    WASP-121, also known as CD-38 3220 and formally named Dilmun, is a magnitude 10.4 star located approximately 858 light-years away in the constellation Puppis. WASP-121 has a mass and radius similar to the Sun's. It hosts one known exoplanet.

    WASP-104b is a hot Jupiter exoplanet that orbits the star WASP-104. It is considered to be one of the darkest exoplanets discovered. WASP-104b was discovered in 2014; according to a 2018 study at Keele University, the planet's dense atmosphere of potassium and sodium absorbs more than 97% of light it receives.

    <span class="mw-page-title-main">WASP-107b</span> Super Neptune orbiting WASP-107

    WASP-107b is a super-Neptune exoplanet that orbits the star WASP-107. It lies 200 light-years away from Earth in the constellation Virgo. Its discovery was announced in 2017 by a team led by D. R. Anderson via the WASP-South.

    WASP-49 is a binary star system about 636 light-years away in the constellation Lepus. The two stars are separated by 443 AU. The primary is a G-type main-sequence star, with a surface temperature of 5,600 K. WASP-49 is depleted of heavy elements relative to the Sun. It has a metallicity Fe/H index of –0.23, meaning it has 59% the iron level of the Sun.

    <span class="mw-page-title-main">WASP-76b</span> Hot Jupiter orbiting WASP-76

    WASP-76b is an exoplanet classified as a Hot Jupiter. It is located in the constellation Pisces and orbits its host star, WASP-76, at a distance of approximately 0.033 AU. Its orbital period is approximately 1.8 days, and its mass is about 0.92 times that of Jupiter. The discovery of WASP-76b took place on October 21, 2013; as of 2022, it is the only known planet in the WASP-76 system. The equilibrium temperature of WASP-76b is estimated to be around 2,190 K, However, the measured daytime temperature is higher, reaching approximately 2,500 ± 200 K.

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

    WASP-178b, also known as KELT-26b and HD 134004 b, is an ultra-hot Jupiter exoplanet discovered in 2019 orbiting WASP-178, a hot A-type star located about 1,350 light-years away in the constellation of Lupus. At over 1.8 times the radius of Jupiter, it is among the largest exoplanets. The planet is tidally locked, heating up one side of the planet to such a degree that silicate rock and metal evaporate. Supersonic winds blow constantly towards the dark, cooler nighttime side, where the vaporized minerals condense and fall as rain.

    References

    1. 1 2 Moskowitz, Clara (October 16, 2008). "Astronomers find hottest planet ever discovered". NBC news. Archived from the original on April 4, 2024. Retrieved April 4, 2024.
    2. 1 2 Öztürk, Oğuz; Erdem, Ahmet (March 14, 2019). "New photometric analysis of five exoplanets: CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b". Monthly Notices of the Royal Astronomical Society. 486 (2): 2290–2307. doi: 10.1093/mnras/stz747 . ISSN   0035-8711.
    3. ↑ Chakrabarty, Aritra; Sengupta, Sujan (July 1, 2019). "Precise Photometric Transit Follow-up Observations of Five Close-in Exoplanets: Update on Their Physical Properties". The Astronomical Journal. 158 (1): 39. arXiv: 1905.11258 . Bibcode:2019AJ....158...39C. doi: 10.3847/1538-3881/ab24dd . ISSN   0004-6256.
    4. 1 2 3 Collins, Karen A; Kielkopf, John F; Stassun, Keivan G (2017). "Transit Timing Variation Measurements of WASP-12b and Qatar-1b: No Evidence for Additional Planets". The Astronomical Journal. 153 (2): 78. arXiv: 1512.00464 . Bibcode:2017AJ....153...78C. doi: 10.3847/1538-3881/153/2/78 . S2CID   55191644.
    5. ↑ Owens, Niall; De Mooij, E J W.; Watson, C. A.; Hooton, M. J. (2021), "Phase curve and variability analysis of WASP-12b using TESS photometry", Monthly Notices of the Royal Astronomical Society: Letters, 503: L38 –L46, arXiv: 2102.00052 , doi: 10.1093/mnrasl/slab014
    6. ↑ Starr, Michelle (April 23, 2018). "Astronomers Just Found a 'Hot Jupiter' So Dark, It Absorbs Nearly 99% of Light". ScienceAlert.
    7. ↑ "WASP Planets". SuperWASP. December 5, 2013. Retrieved January 26, 2016.
    8. ↑ Staff (December 3, 2013). "Hubble Traces Subtle Signals of Water on Hazy Worlds". NASA . Retrieved December 4, 2013.
    9. ↑ Mandell, Avi M.; Haynes, Korey; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake (December 3, 2013). "Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b". Astrophysical Journal . 779 (2): 128. arXiv: 1310.2949 . Bibcode:2013ApJ...779..128M. doi:10.1088/0004-637X/779/2/128. S2CID   52997396.
    10. ↑ Harrington, J.D.; Villard, Ray (July 24, 2014). "RELEASE 14-197 - Hubble Finds Three Surprisingly Dry Exoplanets". NASA . Retrieved July 25, 2014.
    11. ↑ Wall, Mike (September 18, 2017). "The hellish world WASP-12b is darker than fresh asphalt in visible light, but glows red-hot in infrared". Scientific American . Retrieved September 19, 2017.
    12. ↑ Li, Shu-lin; Miller, N.; Lin, Douglas N. C. & Fortney, Jonathan J. (2010). "WASP-12b as a prolate, inflated and disrupting planet from tidal dissipation". Nature . 463 (7284): 1054–1056. arXiv: 1002.4608 . Bibcode:2010Natur.463.1054L. doi:10.1038/nature08715. PMID   20182506. S2CID   4414948.
    13. ↑ Hubble Finds a Star Eating a Planet nasa.gov. 2010-05-20. Retrieved on 2010-12-10.
    14. 1 2 Turner, Jake D.; Ridden-Harper, Andrew; Jayawardhana, Ray (2021), "Decaying Orbit of the Hot Jupiter WASP-12b: Confirmation with TESS Observations", The Astronomical Journal, 161 (2): 72, arXiv: 2012.02211 , Bibcode:2021AJ....161...72T, doi: 10.3847/1538-3881/abd178 , S2CID   227305717
    15. 1 2 Wong, Ian; Shporer, Avi; Vissapragada, Shreyas; Greklek-McKeon, Michael; Knutson, Heather A.; Winn, Joshua N.; Benneke, Björn (January 20, 2022). "TESS Revisits WASP-12: Updated Orbital Decay Rate and Constraints on Atmospheric Variability". The Astronomical Journal. 163 (4): 175. arXiv: 2201.08370 . Bibcode:2022AJ....163..175W. doi: 10.3847/1538-3881/ac5680 . S2CID   246063389.
    16. ↑ 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
    17. ↑ waspplanets (November 26, 2019). "The orbit of WASP-12b is decaying". WASP Planets. Retrieved January 1, 2020.
    18. ↑ Yee, Samuel W.; Winn, Joshua N.; Knutson, Heather A.; Patra, Kishore C.; Vissapragada, Shreyas; Zhang, Michael M.; Holman, Matthew J.; Shporer, Avi; Wright, Jason T. (November 20, 2019). "The Orbit of WASP-12b is Decaying". The Astrophysical Journal. 888: L5. arXiv: 1911.09131 . doi: 10.3847/2041-8213/ab5c16 . S2CID   208202070.
    19. 1 2 Madhusudhan, N.; Harrington, J.; Stevenson, K. B.; Nymeyer, S.; Campo, C. J.; Wheatley, P. J.; Deming, D.; Blecic, J.; Hardy, R. A.; Lust, N. B.; Anderson, D. R.; Collier-Cameron, A.; Britt, C. B. T.; Bowman, W. C.; Hebb, L.; Hellier, C.; Maxted, P. F. L.; Pollacco, D.; West, R. G. (2010). "A high C/O ratio and weak thermal inversion in the atmosphere of exoplanet WASP-12b". Nature. 469 (7328): 64–67. arXiv: 1012.1603 . Bibcode:2011Natur.469...64M. doi:10.1038/nature09602. PMID   21150901. S2CID   4415171.
    20. ↑ "Carbon-Rich Planet: A Girl's Best Friend?". U.S. News & World Report . December 10, 2010.
    21. ↑ Lorianna De Giorgio (December 10, 2010). "Carbon-rich planet could house diamonds". Toronto Star .
    22. ↑ "Diamond planet found by Keele University astronomers". BBC News Online . December 9, 2010.
    23. ↑ Intagliata, Christopher (December 9, 2010). "Exoplanet Strikes Carbon Pay Dirt". Scientific American .
    24. ↑ Российские астрономы впервые открыли луну возле экзопланеты (in Russian) - "Studying of a curve of change of shine of WASP-12b has brought to the Russian astronomers unusual result: regular splashes were found out.<...> Though stains on a star surface also can cause similar changes of shine, observable splashes are very similar on duration, a profile and amplitude that testifies for benefit of exomoon existence."
    25. ↑ Barnes, Jason W.; O'Brien, D. P. (2002). "Stability of Satellites around Close-in Extrasolar Giant Planets". The Astrophysical Journal. 575 (2): 1087–1093. arXiv: astro-ph/0205035 . Bibcode:2002ApJ...575.1087B. doi:10.1086/341477. S2CID   14508244.
    26. ↑ Kislyakova, K. G.; Pilat-Lohinger, E.; Funk, B.; Lammer, H.; Fossati, L.; Eggl, S.; Schwarz, R.; Boudjada, M. Y.; Erkaev, N. V. (2016), "On the ultraviolet anomalies of the WASP-12 and HD 189733 systems: Trojan satellites as a plasma source", Monthly Notices of the Royal Astronomical Society, 461 (1): 988–999, arXiv: 1605.02507 , Bibcode:2016MNRAS.461..988K, doi: 10.1093/mnras/stw1110 , S2CID   119205132

    Commons-logo.svg Media related to WASP-12b at Wikimedia Commons

    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.