WASP-33b

In 2010, the SuperWASP project announced the discovery of an extrasolar planet orbiting the star HD 15082. The discovery was made by detecting the transit of the planet as it passes in front of its star, an event that occurs every 1.22 days.

A study in 2012, utilizing the Rossiter–McLaughlin effect, determined the planetary orbit is strongly misaligned with the equatorial plane of the star, misalignment equal to −107.7{{±|1.6}}°, making the orbit of WASP-33b retrograde.{{Cite journal |last1 = Albrecht |first1 = Simon |last2 = Winn |first2 = Joshua N. |last3 = Johnson |first3 = John A. |last4 = Howard |first4 = Andrew W. |last5 = Marcy |first5 = Geoffrey W. |last6 = Butler |first6 = R. Paul |last7 = Arriagada |first7 = Pamela |last8 = Crane |first8 = Jeffrey D. |last9 = Shectman |first9 = Stephen A. |last10 = Thompson |first10 = Ian B. |last11 = Hirano |first11 = Teruyuki |display-authors = 2 |date = August 30, 2012 |title = Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments |url = https://iopscience.iop.org/article/10.1088/0004-637X/757/1/18 |journal = The Astrophysical Journal |volume = 757 |issue = 1 |page = 18 |arxiv = 1206.6105 |bibcode = 2012ApJ...757...18A |doi = 10.1088/0004-637X/757/1/18 |access-date = March 28, 2022 |last12 = Bakos |first12 = Gaspar |last13 = Hartman |first13 = Joel D. |s2cid = 17174530}} The periastron node is precessing with a period of 709{{±|33|34}} years.{{Cite journal |last1 = Watanabe |first1 = Noriharu |last2 = Narita |first2 = Norio |last3 = Palle |first3 = Enric |date = March 3, 2022 |title = Nodal Precession of WASP-33b for Eleven Years by Doppler Tomographic and Transit Photometric Observations |journal = Monthly Notices of the Royal Astronomical Society|volume = |doi = 10.1093/mnras/stac620 |doi-access = free |arxiv = 2203.02003 }}

Limits from radial velocity measurements imply it has less than 4.1 times the mass of Jupiter. The exoplanet orbits so close to its star that its surface temperature is about {{Convert|3200|C}}.{{Cite web|title = Hottest planet is hotter than some stars|url = https://www.newscientist.com/article/dn19991-hottest-planet-is-hotter-than-some-stars.html|access-date = 2015-06-12}} The transit was later recovered in Hipparcos data.

In June 2015, NASA reported the exoplanet has a stratosphere, and the atmosphere contains titanium monoxide, which creates the stratosphere. Titanium oxide is one of only a few compounds that is a strong absorber of visible and ultraviolet radiation, which heats the atmosphere, and is able to exist in a gas state in a hot atmosphere.{{Cite web |date = June 11, 2015 |editor-last = Northon |editor-first = Karen |title = NASA's Hubble Telescope Detects 'Sunscreen' Layer on Distant Planet |url = https://www.nasa.gov/press-release/nasa-s-hubble-telescope-detects-sunscreen-layer-on-distant-planet |access-date = March 28, 2022 |website = NASA.gov}}{{cite journal |last1 = Haynes |first1 = Korey |last2 = Mandell |first2 = Avi M. |last3 = Madhusudhan |first3 = Nikku |last4 = Deming |first4 = Drake |last5 = Knutson |first5 = Heather |display-authors = 2 |date = June 12, 2015 |title = Spectroscopic Evidence for a Temperature Inversion in the Dayside Atmosphere of the Hot Jupiter WASP-33b |url = https://iopscience.iop.org/article/10.1088/0004-637X/806/2/146 |journal = The Astrophysical Journal |volume = 806 |issue = 2 |pages = 146 |arxiv = 1505.01490 |bibcode = 2015ApJ...806..146H |doi = 10.1088/0004-637X/806/2/146 |access-date = March 28, 2022 |s2cid = 35485407}} This was later confirmed using high-resolution spectroscopy technique with the data taken by High Dispersion Spectrograph mounted on the 8.2 m Subaru telescope.{{cite journal |last1=Nugroho |first1=Stevanus K. |last2=Kawahara |first2=Hajime |last3=Masuda |first3=Kento |last4=Hirano |first4=Teruyuki |last5=Kotani |first5=Takayuki |last6=Tajitsu |first6=Akito |title=High-resolution Spectroscopic Detection of TiO and a Stratosphere in the Day-side of WASP-33b |journal=The Astronomical Journal |date=1 December 2017 |volume=154 |issue=6 |pages=221 |doi=10.3847/1538-3881/aa9433|doi-access=free |arxiv=1710.05276 |bibcode=2017AJ....154..221N }} The detection titanium oxide was not be able to be reproduced with the higher quality data obtained by 2020 although with different setting of observations. Only upper limit of titanium oxide volume mixing rate equal to 1 ppb can be obtained.{{cite journal |last1 = Herman |first1 = Miranda K. |last2 = Mooij |first2 = Ernst J. W. de |last3 = Jayawardhana |first3 = Ray |last4 = Brogi |first4 = Matteo |display-authors = 2 |date = July 31, 2020 |title = Search for TiO and Optical Nightside Emission from the Exoplanet WASP-33b |journal = The Astronomical Journal |volume = 160 |issue = 2 |page = 93 |arxiv = 2006.10743 |bibcode = 2020AJ....160...93H |doi = 10.3847/1538-3881/ab9e77 |s2cid = 219792767 |doi-access = free }} Later research reconfirmed the existence of titanium oxide in the atmosphere of WASP-33b, although in concentrations not detectable by HARPS-N.

The neutral iron {{citation|arxiv = 2007.05508|year = 2020|title = Detection of Fe I Emission in the Dayside Spectrum of WASP-33b|doi = 10.3847/2041-8213/aba4b6|last1 = Nugroho|first1 = S. K. |last2 = Gibson|first2 = N. P. |last3 = De Mooij|first3 = E. J. W. |last4 = Herman|first4 = M. K. |last5 = Watson|first5 = C. A. |last6 = Kawahara|first6 = H.|last7 = Merrit|first7 = S. R. |journal = The Astrophysical Journal Letters|volume = 898| issue=2 |pages = L31| doi-access=free |bibcode = 2020ApJ...898L..31N|s2cid =220486401}}{{citation|arxiv = 2105.10230|year = 2021|title = Detection of Fe and evidence for TiO in the dayside emission spectrum of WASP-33b|doi = 10.1051/0004-6361/202140732|last1 = Cont|first1 = D.|last2 = Yan|first2 = F.|last3 = Reiners|first3 = A.|last4 = Casasayas-Barris|first4 = N.|last5 = Mollière|first5 = P.|last6 = Pallé|first6 = E.|last7 = Henning|first7 = Th.|last8 = Nortmann|first8 = L.|last9 = Stangret|first9 = M.|last10 = Czesla|first10 = S.|last11 = López-Puertas|first11 = M.|last12 = Sánchez-López|first12 = A.|last13 = Rodler|first13 = F.|last14 = Ribas|first14 = I.|last15 = Quirrenbach|first15 = A.|last16 = Caballero|first16 = J. A.|last17 = Amado|first17 = P. J.|last18 = Carone|first18 = L.|last19 = Khaimova|first19 = J.|last20 = Kreidberg|first20 = L.|last21 = Molaverdikhani|first21 = K.|last22 = Montes|first22 = D.|last23 = Morello|first23 = G.|last24 = Nagel|first24 = E.|last25 = Oshagh|first25 = M.|last26 = Zechmeister|first26 = M.|journal = Astronomy & Astrophysics|volume = 651|pages = A33|bibcode = 2021A&A...651A..33C|s2cid = 235125585}} and silicon{{citation|arxiv = 2112.10461|year = 2022|title = Silicon in the dayside atmospheres of two ultra-hot Jupiters|doi = 10.1051/0004-6361/202142776|last1 = Cont|first1 = D.|last2 = Yan|first2 = F.|last3 = Reiners|first3 = A.|last4 = Nortmann|first4 = L.|last5 = Molaverdikhani|first5 = K.|last6 = Pallé|first6 = E.|last7 = Stangret|first7 = M.|last8 = Henning|first8 = Th.|last9 = Ribas|first9 = I.|last10 = Quirrenbach|first10 = A.|last11 = Caballero|first11 = J. A.|last12 = Zapatero Osorio|first12 = M. R.|last13 = Amado|first13 = P. J.|last14 = Aceituno|first14 = J.|last15 = Casasayas-Barris|first15 = N.|last16 = Czesla|first16 = S.|last17 = Kaminski|first17 = A.|last18 = López-Puertas|first18 = M.|last19 = Montes|first19 = D.|last20 = Morales|first20 = J. C.|last21 = Morello|first21 = G.|last22 = Nagel|first22 = E.|last23 = Sánchez-López|first23 = A.|last24 = Sedaghati|first24 = E.|last25 = Zechmeister|first25 = M.|journal = Astronomy & Astrophysics|volume = 657|pages = L2|bibcode = 2022A&A...657L...2C|s2cid = 245302250}} were also detected.

{{Clear}}

File:15-121a-HubbleDetectsStratosphereOnWASP33b-20150611.jpg

In 2020, with the detection of secondary eclipses (when the planet is blocked by its star), the mass of the planet along with temperature profile across its surface was measured. WASP-33b has strong winds in its atmosphere, similar to Venus, shifting the hottest spot 28.7±7.1 degrees to the west. The averaged wind speed is 8.5{{±|2.1|1.9}} km/s in the thermosphere.{{citation |last1 = Wilson Cauley |first1 = P. |title = Time-resolved rotational velocities in the upper atmosphere of WASP-33 b |journal = The Astronomical Journal |volume = 161 |issue = 3 |page = 152 |year = 2021 |arxiv = 2010.02118 |bibcode = 2021AJ....161..152C |doi = 10.3847/1538-3881/abde43 |display-authors = 2 |last2 = Wang |first2 = Ji |last3 = Shkolnik |first3 = Evgenya L. |last4 = Ilyin |first4 = Ilya |last5 = Strassmeier |first5 = Klaus G. |last6 = Redfield |first6 = Seth |last7 = Jensen |first7 = Adam |s2cid = 222132849 |doi-access = free }} The illuminated side brightness temperature is {{Convert|3014|±|60|K|C F}}, while the nightside brightness temperature is {{Convert|1605|±|45|K|C F}}.

The atmospheric escape driven by hydrogen Balmer line absorption is relatively modest, totaling about one to ten Earth masses per billion years.{{Cite journal |last1 = Yan |first1 = F. |last2 = Wyttenbach |first2 = A. |last3 = Casasayas-Barris |first3 = N. |last4 = Reiners |first4 = Ansgar |last5 = Pallé |first5 = E. |last6 = Henning |first6 = Th. |last7 = Mollière |first7 = P. |last8 = Czesla |first8 = S. |last9 = Nortmann |first9 = L. |last10 = Molaverdikhani |first10 = K. |last11 = Chen |first11 = G. |display-authors = 2 |date = January 2021 |orig-date = December 22, 2020 |title = Detection of the hydrogen Balmer lines in the ultra-hot Jupiter WASP-33b |url = https://www.aanda.org/10.1051/0004-6361/202039302 |journal = Astronomy & Astrophysics |volume = 645 |pages = A22 |arxiv = 2011.07888 |bibcode = 2021A&A...645A..22Y |doi = 10.1051/0004-6361/202039302 |issn = 0004-6361 |access-date = March 28, 2022 |last12 = Snellen |first12 = I. A. G. |last13 = Zechmeister |first13 = M. |first14 = C. |last20 = Khalafinejad |last16 = Quirrenbach |first15 = I. |first16 = A. |last17 = Caballero |last18 = Amado |first18 = P. J. |last19 = Cont |first19 = D. |last14 = Huang |first17 = J. A. |first20 = S. |first26 = S. |first24 = E. |last22 = López-Puertas |first22 = M. |last23 = Montes |first23 = D. |last24 = Nagel |last25 = Oshagh |first21 = J. |first25 = M. |last26 = Pedraz |last27 = Stangret |first27 = M. |last21 = Khaimova |s2cid = 226965524 |last15 = Ribas}}

The water in dayside atmosphere of WASP-33b is mostly dissociated to hydroxyl radicals due to high temperature, as planetary emission spectra indicated which was the first detected hydroxyl radicals on a planet outside the Solar System.{{citation|arxiv = 2103.03094|year = 2021|title = First Detection of Hydroxyl Radical Emission from an Exoplanet Atmosphere: High-dispersion Characterization of WASP-33b Using Subaru/IRD|doi = 10.3847/2041-8213/abec71|last1 = Nugroho|first1 = Stevanus K.|last2 = Kawahara|first2 = Hajime|last3 = Gibson|first3 = Neale P.|last4 = De Mooij|first4 = Ernst J. W.|last5 = Hirano|first5 = Teruyuki|last6 = Kotani|first6 = Takayuki|last7 = Kawashima|first7 = Yui|last8 = Masuda|first8 = Kento|last9 = Brogi|first9 = Matteo|last10 = Birkby|first10 = Jayne L.|last11 = Watson|first11 = Chris A.|last12 = Tamura|first12 = Motohide|last13 = Zwintz|first13 = Konstanze|last14 = Harakawa|first14 = Hiroki|last15 = Kudo|first15 = Tomoyuki|last16 = Kuzuhara|first16 = Masayuki|last17 = Hodapp|first17 = Klaus|last18 = Ishizuka|first18 = Masato|last19 = Jacobson|first19 = Shane|last20 = Konishi|first20 = Mihoko|last21 = Kurokawa|first21 = Takashi|last22 = Nishikawa|first22 = Jun|last23 = Omiya|first23 = Masashi|last24 = Serizawa|first24 = Takuma|last25 = Ueda|first25 = Akitoshi|last26 = Vievard|first26 = Sébastien|journal = The Astrophysical Journal Letters|volume = 910|issue = 1|pages = L9|bibcode = 2021ApJ...910L...9N|s2cid = 232110452 | doi-access=free }}{{cite journal |last1=Wright |first1=Sam O. M. |last2=Nugroho |first2=Stevanus K. |last3=Brogi |first3=Matteo |last4=Gibson |first4=Neale P. |last5=de Mooij |first5=Ernst J. W. |last6=Waldmann |first6=Ingo |last7=Tennyson |first7=Jonathan |last8=Kawahara |first8=Hajime |last9=Kuzuhara |first9=Masayuki |last10=Hirano |first10=Teruyuki |last11=Kotani |first11=Takayuki |last12=Kawashima |first12=Yui |last13=Masuda |first13=Kento |last14=Birkby |first14=Jayne L. |last15=Watson |first15=Chris A. |last16=Tamura |first16=Motohide |last17=Zwintz |first17=Konstanze |last18=Harakawa |first18=Hiroki |last19=Kudo |first19=Tomoyuki |last20=Hodapp |first20=Klaus |last21=Jacobson |first21=Shane |last22=Konishi |first22=Mihoko |last23=Kurokawa |first23=Takashi |last24=Nishikawa |first24=Jun |last25=Omiya |first25=Masashi |last26=Serizawa |first26=Takuma |last27=Ueda |first27=Akitoshi |last28=Vievard |first28=Sébastien |last29=Yurchenko |first29=Sergei N. |title=A Spectroscopic Thermometer: Individual Vibrational Band Spectroscopy with the Example of OH in the Atmosphere of WASP-33b |journal=The Astronomical Journal |date=1 August 2023 |volume=166 |issue=2 |pages=41 |doi=10.3847/1538-3881/acdb75|doi-access=free |arxiv=2305.11071 |bibcode=2023AJ....166...41W }}

In view of the high rotational speed of its parent star, the orbital motion of WASP-33b may be affected in a measurable way by the huge oblateness of the star and effects of general relativity.

First, the distorted shape of the star makes its gravitational field deviate from the usual Newtonian inverse-square law. The same is true for the Sun, and part of the precession of the orbit of Mercury is due to this effect. However, it is estimated to be $9\; \backslash times\; 10^9$ greater for WASP-33b.

Other effects will also be greater for WASP-33b. In particular, precession due to general relativistic frame-dragging should be $3\; \backslash times\; 10^5$ greater for WASP-33b than for Mercury, where it is so far too small to have been observed. It has been argued that the oblateness of HD 15082 could be measured at a percent accuracy from a 10-year analysis of the time variations of the planet's transits. Effects due to the planet's oblateness are smaller by at least one order of magnitude, and they depend on the unknown angle between the planet's equator and the orbital plane, perhaps making them undetectable. The effects of frame-dragging are slightly too small to be measured by such an experiment.

Nodal precession of WASP-33b, caused by oblateness of the parent star, was measured by 2021. The gravitational quadrupole moment of the HD 15082 was found to be equal to 6.73{{±|0.22}}×10⁻⁵. The non-Keplerian precession is expected to be 500 times smaller, yet to be detected.{{citation|arxiv = 2105.12138|year = 2021|title = The GAPS Programme at TNG|doi = 10.1051/0004-6361/202140559|last1 = Borsa|first1 = F.|last2 = Lanza|first2 = A. F.|last3 = Raspantini|first3 = I.|last4 = Rainer|first4 = M.|last5 = Fossati|first5 = L.|last6 = Brogi|first6 = M.|last7 = Di Mauro|first7 = M. P.|last8 = Gratton|first8 = R.|last9 = Pino|first9 = L.|last10 = Benatti|first10 = S.|last11 = Bignamini|first11 = A.|last12 = Bonomo|first12 = A. S.|last13 = Claudi|first13 = R.|last14 = Esposito|first14 = M.|last15 = Frustagli|first15 = G.|last16 = Maggio|first16 = A.|last17 = Maldonado|first17 = J.|last18 = Mancini|first18 = L.|last19 = Micela|first19 = G.|last20 = Nascimbeni|first20 = V.|last21 = Poretti|first21 = E.|last22 = Scandariato|first22 = G.|last23 = Sicilia|first23 = D.|last24 = Sozzetti|first24 = A.|last25 = Boschin|first25 = W.|last26 = Cosentino|first26 = R.|last27 = Covino|first27 = E.|last28 = Desidera|first28 = S.|last29 = Di Fabrizio|first29 = L.|last30 = Fiorenzano|first30 = A. F. M.|journal = Astronomy & Astrophysics|volume = 653|pages = A104|s2cid = 235195940|display-authors = 1}}

• WASP-121b

{{Reflist|refs =

{{cite journal | bibcode = 2010MNRAS.407..507C | title = Line-profile tomography of exoplanet transits - II. A gas-giant planet transiting a rapidly rotating A5 star | display-authors = 1 | last1 = Collier Cameron | first1 = A. | last2 = Guenther | first2 = E. | last3 = Smalley | first3 = B. | last4 = McDonald | first4 = I. | last5 = Hebb | first5 = L. | last6 = Andersen | first6 = J. | last7 = Augusteijn | first7 = Th. | last8 = Barros | first8 = S. C. C. | last9 = Brown | first9 = D. J. A. | s2cid = 11989684 | volume = 407 | issue = 1 | year = 2010 | pages = 507 | journal = Monthly Notices of the Royal Astronomical Society | doi = 10.1111/j.1365-2966.2010.16922.x | doi-access = free |arxiv = 1004.4551 }}

{{citation|title = Classical and relativistic node precessional effects in WASP-33b and perspectives for detecting them|journal = Astrophysics and Space Science|arxiv = 1006.2707 |date = 2010-07-25|first = Lorenzo|last = Iorio|s2cid = 119253639|doi = 10.1007/s10509-010-0468-x |bibcode = 2011Ap&SS.331..485I |volume = 331 |issue = 2|pages = 485–496}}

{{cite journal|bibcode = 2018MNRAS.477L..21M|title = Pre-discovery transits of the exoplanets WASP-18b and WASP-33b from Hipparcos|journal = Monthly Notices of the Royal Astronomical Society|volume = 477|issue = 1|pages = L21|last1 = McDonald|first1 = I.|last2 = Kerins|first2 = E.|s2cid = 49547292|year = 2018|arxiv = 1803.06187|doi = 10.1093/mnrasl/sly045| doi-access=free }}

{{cite journal | arxiv = 1710.07642 | title = Phase curves of WASP-33b and HD 149026b and a New Correlation Between Phase Curve Offset and Irradiation Temperature | journal = The Astronomical Journal | volume = 155 | issue = 2 | pages = 83 | last1 = Zhang | first1 = Michael | last2 = Knutson | first2 = Heather A | last3 = Kataria | first3 = Tiffany | last4 = Schwartz | first4 = Joel C | last5 = Cowan | first5 = Nicolas B | last6 = Showman | first6 = Adam P | last7 = Burrows | first7 = Adam | last8 = Fortney | first8 = Jonathan J | last9 = Todorov | first9 = Kamen | last10 = Desert | first10 = Jean-Michel | last11 = Agol | first11 = Eric | last12 = Deming | first12 = Drake | s2cid = 54755276 | display-authors = 1 | year = 2017 | doi = 10.3847/1538-3881/aaa458 | bibcode = 2018AJ....155...83Z | doi-access = free }}

}}{{Andromeda (constellation)}}

{{DEFAULTSORT:WASP-33b}}

Category:Andromeda (constellation)

Category:Exoplanets discovered in 2010

Category:Exoplanets discovered by WASP

Category:Hot Jupiters