Planet Hunters
{{Short description|Citizen science project to find exoplanets}}
{{Infobox website
| name = Planet Hunters
| logo = New Planet Hunters logo.jpeg
| caption = The Zooniverse Planet Hunters logo
| url = {{URL|http://www.planethunters.org}}
| commercial = No
| type = Volunteer Scientific Project
| language = English
| registration = Optional
| owner = Planet Hunters Team
| author = Planet Hunters Team
| launch_date = {{Start date and age|2010|12|16|df=yes|br=yes}}
| current_status = Ongoing
}}
Planet Hunters is a citizen science project to find exoplanets using human eyes. It does this by having users analyze data from the NASA Kepler space telescope and the NASA Transiting Exoplanet Survey Satellite.{{cite web|title=What is Planet Hunters|url=https://www.planethunters.org/#/about|publisher=Planet Hunters website|access-date=24 May 2017}} It was launched by a team led by Debra Fischer at Yale University,{{Cite web|url=http://news.yale.edu/2010/12/16/citizen-scientists-join-search-earth-planets|title = Citizen Scientists Join Search for Earth-like Planets|date = 16 December 2010}} as part of the Zooniverse project.{{cite web|title=The Zooniverse|url=https://www.zooniverse.org/|publisher=Zooniverse website|access-date=9 July 2012}}
History
= Planet Hunters and Planet Hunters 2.0 =
The project was launched on December 16, 2010, after the first Data Release of Kepler data as the Planet Hunters Project.{{Cite web|url=https://blog.planethunters.org/2010/12/16/planet-hunters-introduction/|title=Planet Hunters Introduction|last=Meg|date=2010-12-16|website=Planet Hunters|language=en|access-date=2020-02-11}} 300,000 volunteers participated in the project and the project team published 8 scientific papers. On December 14, 2014, the project was re-launched as Planet Hunters 2.0, with an improved website and considering that the volunteers will look at K2 data.{{Cite web|url=https://blog.planethunters.org/2014/09/18/a-brand-new-planet-hunters/|title=A Brand New Planet Hunters|last=Meg|date=2014-09-18|website=Planet Hunters|language=en|access-date=2020-02-11}} As of November 2018 Planet Hunters had identified 50% of the known planets with an orbital period larger than two years.{{Cite web|url=https://blog.planethunters.org/2018/11/26/planet-hunters-a-new-beginning/|title=Planet Hunters: a new beginning!|last=debrafischer|date=2018-11-26|website=Planet Hunters|language=en|access-date=2020-02-11}}
= Non-Planet Hunters project: Exoplanet Explorers =
In 2017 the project Exoplanet Explorers was launched. It was another planet hunting project at Zooniverse and discovered the system K2-138 and the exoplanet K2-288Bb. This project was launched during the television program Stargazing Live and the discovery of the K2-138 system was announced during the program.{{Cite news|url=https://www.abc.net.au/news/2017-04-06/stargazing-live-four-planets-discovered-in-new-solar-system/8423142|title=Stargazing Live viewers find four-planet solar system|last=Miller|first=Daniel|date=2017-04-06|website=ABC News|language=en-AU|access-date=2020-02-11}}
= Planet Hunters TESS (PHT) =
On December 6, 2018, the project Planet Hunters TESS (PHT) was launched and is led by astronomer Nora Eisner. This project uses data from the Transiting Exoplanet Survey Satellite (TESS) and is currently active (as of March 2023).{{Cite web|url=https://blog.planethunters.org/2018/12/06/planet-hunters-tess/|title=Planet Hunters TESS|last=Zooniverse|first=The|date=2018-12-06|website=Planet Hunters|language=en|access-date=2020-02-11}} This project discovered the Saturn-sized exoplanet TOI-813 b{{Cite journal|last1=Eisner|first1=N. L.|last2=Barragán|first2=O.|last3=Aigrain|first3=S.|last4=Lintott|first4=C.|last5=Miller|first5=G.|last6=Zicher|first6=N.|last7=Boyajian|first7=T. S.|last8=Briceño|first8=C.|last9=Bryant|first9=E. M.|last10=Christiansen|first10=J. L.|last11=Feinstein|first11=A. D.|date=January 2020|title=Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit|journal= Monthly Notices of the Royal Astronomical Society|language=en|volume=494|issue=1|pages=148|doi=10.1093/mnras/staa138|doi-access=free |issn=0035-8711|arxiv=1909.09094|bibcode=2020MNRAS.494..750E}}{{Cite encyclopedia|url=https://exoplanet.eu/catalog/toi_813_b--7187/|encyclopedia=Extrasolar Planets Encyclopaedia|title=The Extrasolar Planet Encyclopaedia — TOI-813 b|access-date=2020-02-11}} and many more.
Until March 2023 PHT discovered 284 exoplanet candidates (e.g. TIC 35021200.01{{Cite web|url=https://exofop.ipac.caltech.edu/tess/target.php?id=35021200|title=PHT candidate TIC 35021200.01|date=2023-03-11|website=ExoFOP|language=en|access-date=2023-03-11}}), 15 confirmed exoplanets (e.g. TOI-5174 b{{Cite web|url=https://exoplanetarchive.ipac.caltech.edu/overview/TOI-5174|title=confirmed TOI-5174 b|date=2023-03-11|website=NASA exoplanet archive|language=en|access-date=2023-03-11}}{{Cite web|url=https://exofop.ipac.caltech.edu/tess/target.php?id=49428710|title=confirmed TOI-5174 b|date=2023-03-11|website=ExoFOP|language=en|access-date=2023-03-11}}) and countless eclipsing binaries. All discovered exoplanet candidates are uploaded to ExoFOP by Nora Eisner or sometimes by another project member (see TOI and CTOI list provided by ExoFOP{{Cite web|url=https://exofop.ipac.caltech.edu/tess/|title=ExoFOP overview|date=2023-03-11|website=ExoFOP|language=en|access-date=2023-03-11}}).
All exoplanet candidates are manually checked by multiple project members (volunteers and moderators) and need to pass different tests before they are accepted by Nora Eisner and uploaded to ExoFOP. But it is possible that not all PHT planet candidates become real (confirmed) exoplanets. Some of them may be grazing eclipsing binaries.
= Planet Hunters: NGTS =
On October 19, 2021, the project Planet Hunters: NGTS was launched. It uses a dataset from the Next Generation Transit Survey to find transiting planets. It is the first Planet Hunters project that uses data from a ground-based telescope. The project looks at candidates that were already automatically filtered, similar to the Exoplanet Explorers project.{{Cite web |last=chrislintott |date=2021-10-19 |title=Welcome to a new Planet Hunters! |url=https://blog.planethunters.org/2021/10/19/welcome-to-a-new-planet-hunters/ |access-date=2022-10-02 |website=Planet Hunters |language=en}} The project found four candidate planets so far.{{Cite web |last=astrosobrien |date=2022-09-09 |title=Planet Hunters NGTS: More detail on our first four Planet Candidates |url=https://blog.planethunters.org/2022/09/09/planet-hunters-ngts-more-detail-on-our-first-four-planet-candidates/ |access-date=2022-10-02 |website=Planet Hunters |language=en}} In the pre-print five candidates are presented. This includes a giant planet candidate around TIC-165227846, a mid-M dwarf.{{Citation |last1=O'Brien |first1=Sean M. |title=Planet Hunters NGTS: New Planet Candidates from a Citizen Science Search of the Next Generation Transit Survey Public Data |date=2024-04-23 |last2=Schwamb |first2=Megan E. |last3=Gill |first3=Samuel |last4=Watson |first4=Christopher A. |last5=Burleigh |first5=Matthew R. |last6=Kendall |first6=Alicia |last7=Anderson |first7=David R. |last8=Vines |first8=José I. |last9=Jenkins |first9=James S.|journal=The Astronomical Journal |volume=167 |issue=5 |page=238 |doi=10.3847/1538-3881/ad32c8 |doi-access=free |arxiv=2404.15395 |bibcode=2024AJ....167..238O }} This candidate was independently detected by Byrant et al. 2023{{Cite journal |last1=Bryant |first1=Edward M. |last2=Bayliss |first2=Daniel |last3=Van Eylen |first3=Vincent |date=2023-05-01 |title=The occurrence rate of giant planets orbiting low-mass stars with TESS |journal=Monthly Notices of the Royal Astronomical Society |volume=521 |issue=3 |pages=3663–3681 |arxiv=2303.00659 |bibcode=2023MNRAS.521.3663B |doi=10.1093/mnras/stad626 |doi-access=free |issn=0035-8711}} and if confirmed could represent the lowest-mass star to host a close-in giant.
Planet hunting
The Planet Hunters project exploits the fact that humans are better at recognising visual patterns than computers. The website displays an image of data collected by the NASA Kepler Space Mission and asks human users (referred to as "Citizen Scientists") to look at the data and see how the brightness of a star changes over time. This brightness data is represented as a graph and referred to as a star's light curve. Such curves are helpful in discovering extrasolar planets due to the brightness of a star decreasing when a planet passes in front of it, as seen from Earth.{{Cite news|url=https://www.nasa.gov/mission_pages/kepler/multimedia/images/transit-light-curve.html|title=Light Curve of a Planet Transiting Its Star|last=Administrator|first=NASA Content|date=2015-04-16|work=NASA|access-date=2017-12-16|language=en}} Periods of reduced brightness can thus provide evidence of planetary transits, but may also be caused by errors in recording, projection, or other phenomena.{{cite web|title=Planet Hunting Tutorial|publisher=Planet Hunters website|url=http://www.planethunters.org/site_guide#video|access-date=9 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120621080836/http://www.planethunters.org/site_guide#video|archive-date=21 June 2012}}
Special occurrence
=Eclipsing binary stars=
From time to time, the project will observe eclipsing binary stars. Essentially these are stars that orbit each other. Much as a planet can interrupt the brightness of a star, another star can too. There is a noticeable difference on the light curves. It will appear as a large transit (a large dip) and a smaller transit (a smaller dip).{{cite web|title=Eclipsing Binary Stars|url=http://www.planethunters.org/site_guide#video|publisher=Planet Hunters website|access-date=10 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120621080836/http://www.planethunters.org/site_guide#video|archive-date=21 June 2012}}{{Cite web|url=https://imagine.gsfc.nasa.gov/educators/hera_college/binary-model.html|title=Eclipsing Binary Light Curves|website=imagine.gsfc.nasa.gov|access-date=2017-12-16}}
=Multiplanet systems=
As of December 2017, there are a total of 621 multiplanet systems, or stars that contains at least two confirmed planets.{{Cite encyclopedia|url=https://exoplanet.eu/catalog/|title=Interactive Extra-solar Planets Catalog|last=Schneider|first=Jean|date=16 December 2017|encyclopedia=Extrasolar Planets Encyclopaedia|access-date=2017-12-16}} In a multiplanet system plot, there are many different patterns of transit. Due to the different sizes of planets, the transits dip down to different points.{{cite web|title=Multiplanet Systems|url=http://www.planethunters.org/site_guide#video|publisher=Planet Hunters website|access-date=10 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120621080836/http://www.planethunters.org/site_guide#video|archive-date=21 June 2012}}
=Stellar flares=
Stellar flares are observed when there is an explosion on the surface of a star. This will cause the star's brightness to shoot up considerably, with a steep drop off.{{cite web|title=Stellar Flares|url=http://www.planethunters.org/site_guide#video|publisher=Planet Hunters website|access-date=10 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120621080836/http://www.planethunters.org/site_guide#video|archive-date=21 June 2012}}
Discoveries
So far, over 12 million observations have been analyzed. Out of those, 34 candidate planets had been found as of July 2012.{{cite web|title=Planetometer|url=http://www.planethunters.org/planetometer|publisher=Planet Hunters website|access-date=10 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20110721124511/http://www.planethunters.org/planetometer|archive-date=21 July 2011}} In October 2012 it was announced that two volunteers from the Planet Hunters initiative had discovered a novel Neptune-like planet which is part of a four star double binary system, orbiting one of the pairs of stars while the other pair of stars orbits at a distance of around 1000 AU. This is the first planet discovered to have a stable orbit in such a complex stellar environment. The system is located 7200 light years away, and the new planet has been designated PH1b, short for Planet Hunters 1 b.{{Cite news|title=Planet with four suns discovered by volunteers|work=BBC News|date=15 October 2012|url=https://www.bbc.co.uk/news/science-environment-19950923|access-date=16 October 2012}}{{Cite journal|bibcode=2013ApJ...768..127S|title=Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System|last1=Schwamb|first1=Megan E.|last2=Orosz|first2=Jerome A.|last3=Carter|first3=Joshua A.|last4=Welsh|first4=William F.|last5=Fischer|first5=Debra A.|last6=Torres|first6=Guillermo|last7=Howard|first7=Andrew W.|last8=Crepp|first8=Justin R.|last9=Keel|first9=William C.|last10=Lintott|first10=Chris J.|last11=Kaib|first11=Nathan A.|last12=Terrell|first12=Dirk|last13=Gagliano|first13=Robert|last14=Jek|first14=Kian J.|last15=Parrish|first15=Michael|last16=Smith|first16=Arfon M.|last17=Lynn|first17=Stuart|last18=Simpson|first18=Robert J.|last19=Giguere|first19=Matthew J.|last20=Schawinski|first20=Kevin|journal=The Astrophysical Journal|volume=1210|date=2012|issue=2|pages=3612|arxiv=1210.3612|display-authors=9|doi=10.1088/0004-637X/768/2/127|s2cid=27456469}}
| class="wikitable"
|+Key | style="background-color: yellow"| {{Hash-tag|alt=circumbinary planet}} |
| style="background-color:#66ff66"| §
| Planet orbiting around one star in a multiple star system (S-class or Satellite-class planet) |
| style="background-color:#ccccff"| {{Double-dagger|alt=multiple planets}}
| Host star with a Planetary system (two or more planets) |
Yellow indicates a circumbinary planet. Light green indicates planet orbiting around one star in a multiple star system. Light blue indicates host stars with a planetary system consisting of two or more planets. Values for the host stars are acquired via SIMBAD{{Cite web|url=http://simbad.u-strasbg.fr/simbad/|title=SIMBAD Astronomical Database - CDS (Strasbourg)|website=simbad.u-strasbg.fr|access-date=2020-02-14}} and otherwise are cited. The apparent magnitude represents the V magnitude.
= Community TESS Object of Interest =
Planet Hunters TESS (PHT) publishes Community TESS Object of Interest (CTOI) at ExoFOP, which can be promoted into a TESS Object of Interest (TOI). Of the 151 CTOIs submitted by Planet Hunters researchers, 81 were promoted to TOIs (as of September 2022).{{Cite web |title=ExoFOP List of CTOIs |url=https://exofop.ipac.caltech.edu/tess/view_ctoi.php |access-date=2022-09-09 |website=exofop.ipac.caltech.edu}} The following exoplanets first submitted as PHT CTOIs were later researched by other teams (some examples): TOI-1759 b,{{Cite web |title=ExoFOP TIC 408636441 |url=https://exofop.ipac.caltech.edu/tess/target.php?id=408636441 |access-date=2022-09-09 |website=exofop.ipac.caltech.edu}}{{Cite journal |last1=Martioli |first1=E. |last2=Hébrard |first2=G. |last3=Fouqué |first3=P. |last4=Artigau |first4=É. |last5=Donati |first5=J. -F. |last6=Cadieux |first6=C. |last7=Bellotti |first7=S. |last8=Lecavelier des Etangs |first8=A. |last9=Doyon |first9=R. |last10=do Nascimento |first10=J. -D. |last11=Arnold |first11=L. |last12=Carmona |first12=A. |last13=Cook |first13=N. J. |last14=Cortes-Zuleta |first14=P. |last15=de Almeida |first15=L. |date=2022-04-01 |title=TOI-1759 b: A transiting sub-Neptune around a low mass star characterized with SPIRou and TESS |url=https://ui.adsabs.harvard.edu/abs/2022A&A...660A..86M |journal=Astronomy and Astrophysics |volume=660 |pages=A86 |doi=10.1051/0004-6361/202142540 |arxiv=2202.01259 |bibcode=2022A&A...660A..86M |s2cid=246485686 |issn=0004-6361}}{{Cite journal |last1=Espinoza |first1=Néstor |last2=Pallé |first2=Enric |last3=Kemmer |first3=Jonas |last4=Luque |first4=Rafael |last5=Caballero |first5=José A. |last6=Cifuentes |first6=Carlos |last7=Herrero |first7=Enrique |last8=Sánchez Béjar |first8=Víctor J. |last9=Stock |first9=Stephan |last10=Molaverdikhani |first10=Karan |last11=Morello |first11=Giuseppe |last12=Kossakowski |first12=Diana |last13=Schlecker |first13=Martin |last14=Amado |first14=Pedro J. |last15=Bluhm |first15=Paz |date=2022-03-01 |title=A Transiting, Temperate Mini-Neptune Orbiting the M Dwarf TOI-1759 Unveiled by TESS |journal=The Astronomical Journal |volume=163 |issue=3 |pages=133 |doi=10.3847/1538-3881/ac4af0 |arxiv=2202.01240 |bibcode=2022AJ....163..133E |s2cid=246485680 |issn=0004-6256 |doi-access=free }} TOI-1899 b,{{Cite journal |last1=Cañas |first1=Caleb I. |last2=Stefansson |first2=Gudmundur |last3=Kanodia |first3=Shubham |last4=Mahadevan |first4=Suvrath |author4-link=Suvrath Mahadevan |last5=Cochran |first5=William D. |last6=Endl |first6=Michael |last7=Robertson |first7=Paul |last8=Bender |first8=Chad F. |last9=Ninan |first9=Joe P. |last10=Beard |first10=Corey |last11=Lubin |first11=Jack |last12=Gupta |first12=Arvind F. |last13=Everett |first13=Mark E. |last14=Monson |first14=Andrew |last15=Wilson |first15=Robert F. |date=2020-09-01 |title=A Warm Jupiter Transiting an M Dwarf: A TESS Single-transit Event Confirmed with the Habitable-zone Planet Finder |journal=The Astronomical Journal |volume=160 |issue=3 |pages=147 |doi=10.3847/1538-3881/abac67 |arxiv=2007.07098 |bibcode=2020AJ....160..147C |s2cid=220514735 |issn=0004-6256 |doi-access=free }} TOI-2180 b,{{Cite journal |last1=Dalba |first1=Paul A. |last2=Kane |first2=Stephen R. |last3=Dragomir |first3=Diana |last4=Villanueva |first4=Steven |last5=Collins |first5=Karen A. |last6=Jacobs |first6=Thomas Lee |last7=LaCourse |first7=Daryll M. |last8=Gagliano |first8=Robert |last9=Kristiansen |first9=Martti H. |last10=Omohundro |first10=Mark |last11=Schwengeler |first11=Hans M. |last12=Terentev |first12=Ivan A. |last13=Vanderburg |first13=Andrew |last14=Fulton |first14=Benjamin |last15=Isaacson |first15=Howard |date=2022-02-01 |title=The TESS-Keck Survey. VIII. Confirmation of a Transiting Giant Planet on an Eccentric 261 Day Orbit with the Automated Planet Finder Telescope |journal=The Astronomical Journal |volume=163 |issue=2 |pages=61 |doi=10.3847/1538-3881/ac415b |arxiv=2201.04146 |bibcode=2022AJ....163...61D |s2cid=245877799 |issn=0004-6256 |doi-access=free }} TOI-4562 b{{Cite web |title=ExoFOP TIC 349576261 |url=https://exofop.ipac.caltech.edu/tess/target.php?id=349576261 |access-date=2022-09-09 |website=exofop.ipac.caltech.edu}}{{Cite journal |last1=Heitzmann |first1=Alexis |last2=Zhou |first2=George |last3=Quinn |first3=Samuel N. |last4=Huang |first4=Chelsea X. |last5=Dong |first5=Jiayin |last6=Bouma |first6=Luke G. |last7=Dawson |first7=Rebekah I. |last8=Marsden |first8=Stephen C. |last9=Wright |first9=Duncan |last10=Petit |first10=Pascal |last11=Collins |first11=Karen A. |last12=Barkaoui |first12=Khalid |last13=Wittenmyer |first13=Robert A. |last14=Gillen |first14=Edward |last15=Brahm |first15=Rafael |title=TOI-4562b: A Highly Eccentric Temperate Jupiter Analog Orbiting a Young Field Star |journal=The Astronomical Journal |year=2023 |volume=165 |issue=3 |page=121 |doi=10.3847/1538-3881/acb5a2 |arxiv=2208.10854 |s2cid=251741424 |doi-access=free |bibcode=2023AJ....165..121H }} and HD 148193 b (TOI-1836).{{Cite web |title=ExoFOP TIC 91987762 |url=https://exofop.ipac.caltech.edu/tess/target.php?id=91987762 |access-date=2024-02-13 |website=exofop.ipac.caltech.edu}}{{Cite journal |last1=Chontos |first1=Ashley |last2=Huber |first2=Daniel |last3=Grunblatt |first3=Samuel K. |last4=Saunders |first4=Nicholas |last5=Winn |first5=Joshua N. |last6=McCormack |first6=Mason |last7=Knudstrup |first7=Emil |last8=Albrecht |first8=Simon H. |last9=Crossfield |first9=Ian J. M. |last10=Rodriguez |first10=Joseph E. |last11=Ciardi |first11=David R. |last12=Collins |first12=Karen A. |last13=Jenkins |first13=Jon M. |last14=Bieryla |first14=Allyson |last15=Batalha |first15=Natalie M. |date=12 Feb 2024 |title=The TESS-Keck Survey XXI: 13 New Planets and Homogeneous Properties for 21 Subgiant Systems |journal=Pre-print |arxiv=2402.07893}}
= Variable stars and unusual systems =
In September 2013 the project discovered the unusual cataclysmic variable KIC 9406652.{{Cite journal|last1=Gies|first1=Douglas R.|last2=Guo|first2=Zhao|last3=Howell|first3=Steve B.|last4=Still|first4=Martin D.|last5=Boyajian|first5=Tabetha S.|last6=Hoekstra|first6=Abe J.|last7=Jek|first7=Kian J.|last8=LaCourse|first8=Daryll|last9=Winarski|first9=Troy|date=September 2013|title=KIC 9406652: An Unusual Cataclysmic Variable in the Kepler Field of View|journal=Astrophysical Journal|language=en|volume=775|issue=1|pages=64|doi=10.1088/0004-637X/775/1/64|arxiv=1308.0369|bibcode=2013ApJ...775...64G|issn=0004-637X|doi-access=free}} In April 2014 the unusually active SU Ursae Majoris-type dwarf nova GALEX J194419.33+491257.0 was discovered. This cataclysmic variable was discovered as a background dwarf nova of KIC 11412044.{{Cite journal|last1=Kato|first1=Taichi|last2=Osaki|first2=Yoji|date=April 2014|title=GALEX J194419.33+491257.0: An unusually active SU UMa-type dwarf nova with a very short orbital period in the Kepler data|journal= Publications of the Astronomical Society of Japan|language=en|volume=66|issue=2|pages=L5|doi=10.1093/pasj/psu025|arxiv=1403.0308|bibcode=2014PASJ...66L...5K|issn=0004-6264|doi-access=free}}
In January 2016 unusual dips in KIC 8462852 were announced. The unusual light curve of KIC 8462852 (also known as Boyajian's Star)
{{cite journal
|last1=Boyajian |first1=T. S.
|display-authors=etal
|date=27 January 2016
|title=Planet Hunters X: KIC 8462852 – Where's the flux?
|journal=Monthly Notices of the Royal Astronomical Society
|volume=457 |issue=4 |pages=3988–4004
|doi=10.1093/mnras/stw218
|doi-access=free
|arxiv=1509.03622
|bibcode = 2016MNRAS.457.3988B }} has engendered speculation that an alien civilization's Dyson sphere{{cite web |first=Chris |last=Bodenner |url=https://www.theatlantic.com/notes/all/2015/10/maybe-its-a-dyson-sphere/411121/#note-410974 |title=Maybe It's a Dyson Sphere |publisher=The Atlantic |work=Notes |date=16 October 2015 |access-date=15 June 2017}}{{cite web |first=Chris |last=Bodenner |url=https://www.theatlantic.com/notes/all/2015/10/maybe-its-a-dyson-sphere/411121/#note-411124 |title=Maybe It's a Dyson Sphere, Cont'd |publisher=The Atlantic |work=Notes |date=17 October 2015 |access-date=15 June 2017}} is responsible.{{cite magazine |first=Ross |last=Andersen |url=https://www.theatlantic.com/science/archive/2015/10/the-most-interesting-star-in-our-galaxy/410023/ |title=The Most Mysterious Star in Our Galaxy |magazine=The Atlantic |date=13 October 2015 |access-date=15 June 2017}}
In June 2016 the project found 32 likely eclipsing binaries. The work also announced likely exoplanets.{{Cite journal|last1=Schmitt|first1=Joseph R.|last2=Tokovinin|first2=Andrei|last3=Wang|first3=Ji|last4=Fischer|first4=Debra A.|last5=Kristiansen|first5=Martti H.|last6=LaCourse|first6=Daryll M.|last7=Gagliano|first7=Robert|last8=Tan|first8=Arvin Joseff V.|last9=Schwengeler|first9=Hans Martin|last10=Omohundro|first10=Mark R.|last11=Venner|first11=Alexander|date=June 2016|title=Planet Hunters. X. Searching for Nearby Neighbors of 75 Planet and Eclipsing Binary Candidates from the K2 Kepler extended mission|journal=The Astronomical Journal |language=en|volume=151|issue=6|pages=159|doi=10.3847/0004-6256/151/6/159|arxiv=1603.06945|bibcode=2016AJ....151..159S|s2cid=1711279|issn=0004-6256 |doi-access=free }}
In February 2018 the first transiting exocomets were discovered. The dips were found by one of the authors, a Planet Hunters participant, in a visual search over five months of the complete Q1-Q17 Kepler light curve archive spanning 201250 target stars.{{Cite web|url=https://www.newsweek.com/comets-detected-outside-our-solar-system-first-time-696446|title=Astronomers have detected comets outside our solar system for the first time ever|last=EDT|first=Meghan Bartels On 10/30/17 at 2:24 PM|date=2017-10-30|website=Newsweek|language=en|access-date=2020-02-11}}{{Cite journal|last1=Rappaport|first1=S.|last2=Vanderburg|first2=A.|last3=Jacobs|first3=T.|last4=LaCourse|first4=D.|last5=Jenkins|first5=J.|last6=Kraus|first6=A.|last7=Rizzuto|first7=A.|last8=Latham|first8=D. W.|last9=Bieryla|first9=A.|last10=Lazarevic|first10=M.|last11=Schmitt|first11=A.|date=February 2018|title=Likely transiting exocomets detected by Kepler|journal=MNRAS|language=en|volume=474|issue=2|pages=1453–1468|doi=10.1093/mnras/stx2735|pmid=29755143|pmc=5943639|arxiv=1708.06069|bibcode=2018MNRAS.474.1453R|issn=0035-8711|doi-access=free}}
In February 2022 Planet Hunters:TESS announced the discovery of BD+61 2536 (TIC 470710327), a massive hierarchical triple star system. The system is predicted to undergo multiple phases of mass transfer in the future, and likely end up as a double neutron star gravitational wave progenitor or an exotic Thorne-Zytkow object.{{Cite journal |last1=Eisner |first1=N. L. |last2=Johnston |first2=C. |last3=Toonen |first3=S. |last4=Frost |first4=A. J. |last5=Janssens |first5=S. |last6=Lintott |first6=C. J. |last7=Aigrain |first7=S. |last8=Sana |first8=H. |last9=Abdul-Masih |first9=M. |last10=Arellano-Córdova |first10=K. Z. |last11=Beck |first11=P. G. |last12=Bordier |first12=E. |last13=Cannon |first13=E. |last14=Escorza |first14=A. |last15=Fabry |first15=M. |date=2022-04-01 |title=Planet Hunters TESS IV: a massive, compact hierarchical triple star system TIC 470710327 |journal=Monthly Notices of the Royal Astronomical Society |volume=511 |issue=4 |pages=4710–4723 |doi=10.1093/mnras/stab3619 |doi-access=free |arxiv=2202.06964 |bibcode=2022MNRAS.511.4710E |issn=0035-8711}}
See also
{{Portal|Astronomy}}
Zooniverse projects:
{{div col|colwidth=30}}
- Amateur exoplanet discoveries
- Asteroid Zoo
- Backyard Worlds
- Disk Detective
- Galaxy Zoo
- Old Weather
- SETILive
- The Milky Way Project
{{div col end}}
References
{{reflist}}
External links
- {{Official website|http://www.planethunters.org/}}
Category:Human-based computation