| Revision as of 06:26, 16 December 2017 editHmains (talk | contribs)Autopatrolled, Extended confirmed users, Pending changes reviewers1,214,060 editsm AWB general fixes and delink dates per WP:DATELINK, WP:YEARLINK and MOS:UNLINKYEARS using AWB← Previous edit | Revision as of 04:06, 4 February 2018 edit undo2600:1700:23a0:50a0:8e9:f0f8:4151:2ca (talk) i erased itTags: Replaced blankingNext edit → | ||
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| a | |||
| {{Planetbox begin | |||
| | name= 51 Pegasi b | |||
| }} | |||
| {{Planetbox image | |||
| | image = Artist impression of the exoplanet 51 Pegasi b.jpg | |||
| | caption = An artist's impression of 51 Pegasi b (center) and its star (right). | |||
| }} | |||
| {{Planetbox star | |||
| | star = ] | |||
| | constell = ] | |||
| | RA = {{RA|22|57|28.0}} | |||
| | DEC = {{DEC|+20|46|08}} | |||
| | app_mag = 5.49 | |||
| | dist_ly = 50.9 ± 0.3 | |||
| | dist_pc = 15.61 ± 0.09 | |||
| | class = G2.5IVa ''or'' G4-5Va | |||
| | mass = 1.06 | |||
| | radius = 1.237 ± 0.047 | |||
| | temperature = 5571 ± 102 | |||
| | metallicity = 0.20 ± 0.07 | |||
| | age = 6.1-8.1 | |||
| }} | |||
| {{Planetbox orbit | |||
| | semimajor = 0.0527 ± 0.0030 | |||
| | semimajor_gm = 7.89 | |||
| | periastron = 0.0520 | |||
| | periastron_gm = 7.79 | |||
| | apastron = 0.0534 | |||
| | apastron_gm = 7.99 | |||
| | eccentricity = 0.013 ± 0.012 | |||
| | period = 4.230785 ± 0.000036 | |||
| | period_hour = 101.5388 | |||
| | speed = 136 | |||
| | arg_peri = 58 | |||
| | t_peri = 2,450,001.51 ± 0.61 | |||
| | semi-amp = 55.94 ± 0.69 | |||
| }} | |||
| {{Planetbox character | |||
| | minimum_mass = 0.472 ± 0.039 | |||
| | temperature = 1284 ± 19 | |||
| | stellar_flux = 480 | |||
| | rotation_period = Synchronous | |||
| }} | |||
| {{Planetbox discovery | |||
| | discovery_date = 6 October 1995 | |||
| | discoverers = ] and<br>] | |||
| | discovery_site= ], France | |||
| | discovery_method = ] (]) | |||
| | discovery_status = Published | |||
| }} | |||
| {{Planetbox catalog | |||
| | names = Dimidium, ] | |||
| }} | |||
| {{Planetbox reference | |||
| | star = 51+Peg | |||
| | planet = b | |||
| }} | |||
| {{Planetbox end}} | |||
| '''51 Pegasi b''' (abbreviated '''51 Peg b'''), unofficially dubbed '''Bellerophon''', later named '''Dimidium''', is an ] approximately 50 ]s away in the ] of ]. It was the first ] to be discovered ]ing a ] star,<ref name=HTUW>{{cite AV media | title=How the Universe Works 3 | volume=Jupiter: Destroyer or Savior? | date=2014 | publisher=]}}</ref> the ] ], and marked a breakthrough in astronomical ]. It is the ] for a class of ]s called ]s. | |||
| In 2017, traces of ] were discovered in the ]'s ].<ref>{{Cite web|url=https://phys.org/news/2017-02-atmosphere-hot-jupiter-exoplanet-pegasi.html|title=Water detected in the atmosphere of hot Jupiter exoplanet 51 Pegasi b|last=|first=|date=February 1, 2017|website=phys.org|archive-url=|archive-date=|dead-url=|access-date=}}</ref> | |||
| == Name == | |||
| ] is the ] of the host ]. The ] was originally designated 51 Pegasi b by ] and ], who discovered the ] on December 1995. The following ] it was unofficially dubbed ] by ] ], who followed the ] of naming ]s after ] and ] ]s (] was a figure from ] who rode the winged ] ]).<ref></ref> | |||
| In July 2014, the ] launched a process for giving proper ]s to certain ]s and their host ]s.<ref>. IAU.org. 9 July 2014</ref> The process involved public nomination and voting for the new names.<ref></ref> In December 2015, the ] announced the winning ] for this ] was ].<ref>, International Astronomical Union, 15 December 2015.</ref> The name was submitted by the ] ({{lang-for||German|Astronomical Society of Lucerne}}), ]. 'Dimidium' is ] for 'half', referring to the ]'s ] of at least half the ] of ].<ref></ref> | |||
| == Discovery == | |||
| ] in ]]] | |||
| The ]'s discovery was announced on October 6, 1995, by ] and ] of the ] in the journal '']''.<ref>{{cite journal | author=Mayor, Michael | author2=Queloz, Didier | title=A Jupiter-mass companion to a solar-type star | journal=] | volume=378 |issue=6555 |date=1995 | pages=355–359| doi=10.1038/378355a0| bibcode=1995Natur.378..355M}}</ref> They used the ] with the ] on the ] ] in ] and made ] ]s with their announcement. | |||
| The ] was discovered using a sensitive ] that could detect the slight and regular ] changes in the star's ]s of around 70 ]s per ]. These changes are caused by the ]'s ]al effects from just 7 million ]s' distance from the ]. | |||
| Within a week of the announcement, the planet was confirmed by another team using the ] in ].<ref>{{cite journal|title=51 Pegasi|journal=]|volume=6251|pages=1|url=http://www.cbat.eps.harvard.edu/iauc/06200/06251.html#Item1|bibcode=1995IAUC.6251....1M|author1=Mayor|first1=M.|last2=Queloz|first2=D.|last3=Marcy|first3=G.|last4=Butler|first4=P.|last5=Noyes|first5=R.|last6=Korzennik|first6=S.|last7=Krockenberger|first7=M.|last8=Nisenson|first8=P.|last9=Brown|first9=T.|last10=Kennelly|first10=T.|last11=Rowland|first11=C.|last12=Horner|first12=S.|last13=Burki|first13=G.|last14=Burnet|first14=M.|last15=Kunzli|first15=M.|year=1995}}</ref> | |||
| This was the first discovery of an exoplanet orbiting a Sun-like star (the first exoplanet discovery was made by ] in 1992, around ] ]). It marked a turning point and forced astronomers to accept that giant planets could exist in short-period orbits. Once astronomers realized that it was worth looking for giant planets with the currently available technology, much more telescope time was devoted to radial velocity planet searches, and hence many more exoplanets in the ]'s neighborhood were discovered. | |||
| == Physical characteristics == | |||
| {{refimprove section|date=October 2014}} | |||
| After its discovery, many teams confirmed the planet's existence and obtained more observations of its properties. It was discovered that the planet orbits the star in around 4 ]s. It is much closer to it than ] is to the Sun,<ref name=HTUW/> moves at an ] of 136 km/s, yet has a minimum mass about half that of ] (about 150 times that of the ]). At the time, the presence of a huge world so close to its star was not compatible with theories of ] and was considered an anomaly. However, since then, numerous other 'hot Jupiters' have been discovered<ref name=HTUW/> (see ] and ], for example), and astronomers are revising their theories of planet formation to account for them by studying ]. | |||
| Assuming the planet is perfectly grey with no greenhouse or tidal effects, and a ] of 0.1, the temperature would be 1265 ] (approximately 1000 °C / 1800 °F). This is between the predicted temperatures of ] and ] (1180–1392 K), before they were measured.<ref name=Renard>{{cite journal | journal=Proceedings of SPIE|date=2008 | last1=Renard | first1=S. | last2=Absil | first2=O. | last3=Berger | first3=J. -P. | last4=Bonfils | first4=X. | last5=Forveille | first5=T. | last6=Malbet | first6=F. | doi=10.1117/12.790494 | title=Prospects for near-infrared characterisation of hot Jupiters with the VLTI Spectro-Imager (VSI) | volume=7013 | pages=70132Z|arxiv = 0807.3014 |series=Optical and Infrared Interferometry |bibcode=2008SPIE.7013E..2ZR }}</ref> | |||
| In the report of the discovery it was initially speculated that 51 Pegasi b was the stripped core of a brown dwarf that formed in situ and was therefore composed of heavy elements, but it is now believed to be a ]. It is sufficiently massive that its thick atmosphere is not blown away by the star's ]. | |||
| 51 Pegasi b probably has a greater ] than that of Jupiter despite its lower mass. This is because its superheated atmosphere must be puffed up into a thick but tenuous layer surrounding it. Beneath this, the gases that make up the planet would be so hot that the planet would glow red. Clouds of ] may exist in the atmosphere. | |||
| The planet is ] to its star, always presenting the same face to it. | |||
| The planet (with ]) is deemed a candidate for direct imaging by ].<ref name=lucas>{{cite journal | title=Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo | date=2007 | last1=Lucas | first1=P. W. | last2=Hough | first2=J. H. | last3=Bailey | first3=J. A. | last4=Tamura | first4=M. | last5=Hirst | first5=E. | last6=Harrison | first6=D. | doi=10.1111/j.1365-2966.2008.14182.x | journal=] | volume=393 | pages=229 | arxiv=0807.2568 |bibcode = 2009MNRAS.393..229L }}</ref> It is also a candidate for "near-infrared characterisation.... with the VLTI Spectro-Imager".<ref name=Renard /> | |||
| == Direct detection of visible light == | |||
| The first ever direct detection of the ] reflected from an exoplanet has been made by an international team of astronomers on 51 Pegasi b. The astronomers studied light from 51 Pegasi b using the High Accuracy Radial velocity Planet Searcher (HARPS) instrument at the European Southern Observatory's ] in Chile.<ref></ref><ref>{{cite journal |doi=10.1051/0004-6361/201425298|title=Evidence for a spectroscopic direct detection of reflected light from 51 Pegasi b|journal=Astronomy & Astrophysics|volume=576|pages=A134|date=2015|last1=Martins|first1=J. H. C.|last2=Santos|first2=N. C.|last3=Figueira|first3=P.|last4=Faria|first4=J. P.|last5=Montalto|first5=M.|last6=Boisse|first6=I.|last7=Ehrenreich|first7=D.|last8=Lovis|first8=C.|last9=Mayor|first9=M.|last10=Melo|first10=C.|last11=Pepe|first11=F.|last12=Sousa|first12=S. G.|last13=Udry|first13=S.|last14=Cunha|first14=D.|bibcode=2015A&A...576A.134M|arxiv = 1504.05962 }}</ref> | |||
| == See also == | |||
| * ] | |||
| * ] | |||
| * ] | |||
| == References == | |||
| {{Reflist|25em}} | |||
| == Further reading == | |||
| *{{cite journal | url=http://www.iop.org/EJ/article/0004-637X/646/1/505/64046.html | author=Butler | title=Catalog of Nearby Exoplanets | journal=The ] | volume=646 | issue=1 | pages=505–522 | date=2006 | doi=10.1086/504701 | last2=Wright | first2=J. T. | last3=Marcy | first3=G. W. | last4=Fischer | first4=D. A. | last5=Vogt | first5=S. S. | last6=Tinney | first6=C. G. | last7=Jones | first7=H. R. A. | last8=Carter | first8=B. D. | last9=Johnson | first9=J. A. | last10 = McCarthy | first10=C. | last11=Penny | first11=A.J. | bibcode=2006ApJ...646..505B|arxiv = astro-ph/0607493 |display-authors=etal}} () | |||
| == External links == | |||
| * {{cite web |url=http://exoplanet.eu/planet.php?p1=51+Peg&p2=b |title=Notes for Planet 51 Peg b |author=Jean Schneider |date=2011 |publisher=] |accessdate=3 October 2011}} | |||
| * {{cite web |url=http://www.solstation.com/stars2/51pegasi.htm |title=51 Pegasi |accessdate=2008-07-03 |work=SolStation | archiveurl= https://web.archive.org/web/20080725012818/http://www.solstation.com/stars2/51pegasi.htm| archivedate= 25 July 2008 <!--DASHBot-->| deadurl= no}} | |||
| * {{cite web | url=http://media4.obspm.fr/exoplanets/base/etoile.php?nom=51+Peg | title=51 Peg | work=Exoplanets}} | |||
| * {{cite web |url=http://obswww.unige.ch/~udry/planet/51peg.html |title=The First Extrasolar Planet around a Solar-type Star |accessdate=2008-07-03 |work=] | archiveurl= https://web.archive.org/web/20080609085714/http://obswww.unige.ch/~udry/planet/51peg.html| archivedate= 9 June 2008 <!--DASHBot-->| deadurl= no}} | |||
| * {{cite web |url=http://exoplanets.org/esp/51peg/51peg.shtml |title=The Planet Around 51 Peg |accessdate=2008-07-03 |work=] | archiveurl= https://web.archive.org/web/20080727005731/http://exoplanets.org/esp/51peg/51peg.shtml| archivedate= 27 July 2008 <!--DASHBot-->| deadurl= no}} | |||
| {{Sky|22|57|28.0|+|20|46|08|50.1}} | |||
| {{DEFAULTSORT:51 Pegasi B}} | |||
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Revision as of 04:06, 4 February 2018
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