Editing Protoplanet (section)

=== Unconfirmed protoplanets ===
The confident detection of protoplanets is difficult. Protoplanets usually exist in gas-rich protoplanetary disks. Such disks can produce over-densities by a process called disk fragmentation. Such fragments can be small enough to be unresolved and mimic the appearance of a protoplanet.<ref>{{Cite journal |last1=Teague |first1=Richard |last2=Jankovic |first2=Marija R. |last3=Haworth |first3=Thomas J. |last4=Qi |first4=Chunhua |last5=Ilee |first5=John D. |date=2020-06-01 |title=A three-dimensional view of Gomez's hamburger |journal=Monthly Notices of the Royal Astronomical Society |volume=495 |issue=1 |pages=451–459 |doi=10.1093/mnras/staa1167 |doi-access=free |arxiv=2003.02061 |bibcode=2020MNRAS.495..451T |issn=0035-8711}}</ref> A number of unconfirmed protoplanet candidates are known and some detections were later questioned.
{| class="wikitable"
|+List of unconfirmed/disputed/refuted protoplanets
!Star/host
!Exoplanet
!Mass<br/>({{Jupiter mass|link=true}})
!Period<br/>(yr)
!Separation<br/>([[Astronomical unit|AU]])
!Distance to Earth<br/>([[Parsec]])
!Year of Discovery
!Status
!Detection technique
|-
|[[DH Tauri]]
|DH Tauri b
|8-50
|
|330
|135
|2005<ref>{{Cite journal |last=Itoh |first=Yoichi |last2=Hayashi |first2=Masahiko |last3=Tamura |first3=Motohide |last4=Tsuji |first4=Takashi |last5=Oasa |first5=Yumiko |last6=Fukagawa |first6=Misato |last7=Hayashi |first7=Saeko S. |last8=Naoi |first8=Takahiro |last9=Ishii |first9=Miki |last10=Mayama |first10=Satoshi |last11=Morino |first11=Jun‐ichi |last12=Yamashita |first12=Takuya |last13=Pyo |first13=Tae‐Soo |last14=Nishikawa |first14=Takayuki |last15=Usuda |first15=Tomonori |date=2005-02-20 |title=A Young Brown Dwarf Companion to DH Tauri |url=https://iopscience.iop.org/article/10.1086/427086 |journal=The Astrophysical Journal |language=en |volume=620 |issue=2 |pages=984–993 |arxiv=astro-ph/0411177 |bibcode=2005ApJ...620..984I |doi=10.1086/427086 |issn=0004-637X}}</ref>
|unconfirmed planetary mass and formation in disk
|Direct imaging
|-
|[[GQ Lupi]]
|[[GQ Lupi b]]
|1-36
|
|103
|152
|2005<ref>{{Cite journal |last=Neuhäuser |first=R. |last2=Guenther |first2=E. W. |last3=Wuchterl |first3=G. |last4=Mugrauer |first4=M. |last5=Bedalov |first5=A. |last6=Hauschildt |first6=P. H. |date=May 2005 |title=Evidence for a co-moving sub-stellar companion of GQ Lup |url=http://www.aanda.org/10.1051/0004-6361:200500104 |journal=Astronomy & Astrophysics |volume=435 |issue=1 |pages=L13–L16 |arxiv=astro-ph/0503691 |bibcode=2005A&A...435L..13N |doi=10.1051/0004-6361:200500104 |issn=0004-6361}}</ref>
|unconfirmed planetary mass and formation in disk
|Direct imaging
|-
|[[2M1207]]
|[[2M1207b]]
|5-6
|
|49.8
|65
|2005<ref>{{Cite journal |last=Chauvin |first=G. |last2=Lagrange |first2=A.-M. |last3=Dumas |first3=C. |last4=Zuckerman |first4=B. |last5=Mouillet |first5=D. |last6=Song |first6=I. |last7=Beuzit |first7=J.-L. |last8=Lowrance |first8=P. |date=August 2005 |title=Giant planet companion to 2MASSW J1207334-393254 |url=http://www.aanda.org/10.1051/0004-6361:200500116 |journal=Astronomy & Astrophysics |volume=438 |issue=2 |pages=L25–L28 |arxiv=astro-ph/0504659 |bibcode=2005A&A...438L..25C |doi=10.1051/0004-6361:200500116 |issn=0004-6361}}</ref>
|unconfirmed formation in disk
|Direct imaging
|-
| rowspan="3" |[[LkCa 15]]
|LkCa 15 b
|
|
|12.7
|
|2012<ref name=":7">{{Cite journal |last1=Kraus |first1=Adam L. |last2=Ireland |first2=Michael J. |date=2012-01-01 |title=LkCa 15: A Young Exoplanet Caught at Formation? |url=https://ui.adsabs.harvard.edu/abs/2012ApJ...745....5K |journal=The Astrophysical Journal |volume=745 |issue=1 |pages=5 |doi=10.1088/0004-637X/745/1/5 |arxiv=1110.3808 |bibcode=2012ApJ...745....5K |issn=0004-637X}}</ref>
| rowspan="3" |refuted in 2019<ref name=":8">{{Cite journal |last1=Currie |first1=Thayne |last2=Marois |first2=Christian |last3=Cieza |first3=Lucas |last4=Mulders |first4=Gijs D. |last5=Lawson |first5=Kellen |last6=Caceres |first6=Claudio |last7=Rodriguez-Ruiz |first7=Dary |last8=Wisniewski |first8=John |last9=Guyon |first9=Olivier |last10=Brandt |first10=Timothy D. |last11=Kasdin |first11=N. Jeremy |last12=Groff |first12=Tyler D. |last13=Lozi |first13=Julien |last14=Chilcote |first14=Jeffrey |last15=Hodapp |first15=Klaus |date=2019-05-01 |title=No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals |journal=The Astrophysical Journal |volume=877 |issue=1 |pages=L3 |doi=10.3847/2041-8213/ab1b42 |doi-access=free |arxiv=1905.04322 |bibcode=2019ApJ...877L...3C |issn=0004-637X}}</ref>
|Direct imaging
|-
|LkCa 15 c
|
|
|18.6
|
|2015<ref name=":6">{{Cite journal |last1=Sallum |first1=S. |last2=Follette |first2=K. B. |last3=Eisner |first3=J. A. |last4=Close |first4=L. M. |last5=Hinz |first5=P. |last6=Kratter |first6=K. |last7=Males |first7=J. |last8=Skemer |first8=A. |last9=Macintosh |first9=B. |last10=Tuthill |first10=P. |last11=Bailey |first11=V. |last12=Defrère |first12=D. |last13=Morzinski |first13=K. |last14=Rodigas |first14=T. |last15=Spalding |first15=E. |date=2015-11-01 |title=Accreting protoplanets in the LkCa 15 transition disk |url=https://ui.adsabs.harvard.edu/abs/2015Natur.527..342S |journal=Nature |volume=527 |issue=7578 |pages=342–344 |doi=10.1038/nature15761 |pmid=26581290 |arxiv=1511.07456 |bibcode=2015Natur.527..342S |s2cid=916170 |issn=0028-0836}}</ref>
|Direct imaging
|-
|LkCa 15 d
|
|
|24.7
|
|2015<ref name=":6" />
|Direct imaging
|-
|[[HD 100546]]
|HD 100546 b
|4–13<ref>{{Cite journal |last1=Quanz |first1=Sascha P. |last2=Amara |first2=Adam |last3=Meyer |first3=Michael R. |last4=Girard |first4=Julien H. |last5=Kenworthy |first5=Matthew A. |last6=Kasper |first6=Markus |date=2015-07-01 |title=Confirmation and Characterization of the Protoplanet HD 100546 b—Direct Evidence for Gas Giant Planet Formation at 50 AU |url=https://ui.adsabs.harvard.edu/abs/2015ApJ...807...64Q |journal=The Astrophysical Journal |volume=807 |issue=1 |pages=64 |arxiv=1412.5173 |bibcode=2015ApJ...807...64Q |doi=10.1088/0004-637X/807/1/64 |hdl=1887/48578 |issn=0004-637X |s2cid=119119314}}</ref>
|249<ref name=":0" />
|53 ± 2
|108<ref name=":1" />
|2015<ref>{{Cite web |title=HD 100546 {{!}} NASA Exoplanet Archive |url=https://exoplanetarchive.ipac.caltech.edu/overview/HD%20100546%20b#planet_HD-100546-b_collapsible |access-date=2023-03-01 |website=exoplanetarchive.ipac.caltech.edu}}</ref>
|disputed in 2017<ref>{{Cite journal |last1=Rameau |first1=Julien |last2=Follette |first2=Katherine B. |last3=Pueyo |first3=Laurent |last4=Marois |first4=Christian |last5=Macintosh |first5=Bruce |last6=Millar-Blanchaer |first6=Maxwell |last7=Wang |first7=Jason J. |last8=Vega |first8=David |last9=Doyon |first9=René |last10=Lafrenière |first10=David |last11=Nielsen |first11=Eric L. |last12=Bailey |first12=Vanessa |last13=Chilcote |first13=Jeffrey K. |last14=Close |first14=Laird M. |last15=Esposito |first15=Thomas M. |date=2017-06-01 |title=An Optical/Near-infrared Investigation of HD 100546 b with the Gemini Planet Imager and MagAO |journal=The Astronomical Journal |volume=153 |issue=6 |pages=244 |arxiv=1704.06317 |bibcode=2017AJ....153..244R |doi=10.3847/1538-3881/aa6cae |issn=0004-6256 |s2cid=19100982 |doi-access=free}}</ref>
|Direct imaging
|-
|[[Gomez's Hamburger]]
|GoHam b
|{{nowrap|0.8–11.4}}
|
|350 ± 50
|250
|2015<ref>{{Cite journal |last1=Berné |first1=O. |last2=Fuente |first2=A. |last3=Pantin |first3=E. |last4=Bujarrabal |first4=V. |last5=Baruteau |first5=C. |last6=Pilleri |first6=P. |last7=Habart |first7=E. |last8=Ménard |first8=F. |last9=Cernicharo |first9=J. |last10=Tielens |first10=A. G. G. M. |last11=Joblin |first11=C. |date=2015-06-01 |title=Very Large Telescope observations of Gomez's Hamburger: Insights into a young protoplanet candidate |url=https://ui.adsabs.harvard.edu/abs/2015A&A...578L...8B |journal=Astronomy and Astrophysics |volume=578 |pages=L8 |doi=10.1051/0004-6361/201526041 |arxiv=1504.02735 |bibcode=2015A&A...578L...8B |issn=0004-6361}}</ref>
|unconfirmed candidate
|Direct imaging
|-
|[[AB Aurigae]]
|[[AB Aurigae b|AB Aur b]]
|9
|
|94 ± 49
|156<ref name=":1" />
|2022<ref>{{Cite web |title=AB Aur {{!}} NASA Exoplanet Archive |url=https://exoplanetarchive.ipac.caltech.edu/overview/AB%20Aur%20b#planet_AB-Aur-b_collapsible |access-date=2023-03-01 |website=exoplanetarchive.ipac.caltech.edu}}</ref>
|disputed in 2023<ref>{{Cite journal |last1=Zhou |first1=Yifan |last2=Bowler |first2=Brendan P. |last3=Yang |first3=Haifeng |last4=Sanghi |first4=Aniket |last5=Herczeg |first5=Gregory J. |last6=Kraus |first6=Adam L. |last7=Bae |first7=Jaehan |last8=Long |first8=Feng |last9=Follette |first9=Katherine B. |last10=Ward-Duong |first10=Kimberley |last11=Zhu |first11=Zhaohuan |last12=Biddle |first12=Lauren I. |last13=Close |first13=Laird M. |last14=Yushu Jiang |first14=Lillian |last15=Wu |first15=Ya-Lin |date=30 Aug 2023 |title=UV-Optical Emission of AB Aur b is Consistent with Scattered Stellar Light |journal=Astrophysical Journal |volume=166 |issue=6 |pages=11 |arxiv=2308.16223 |bibcode=2023AJ....166..220Z |doi=10.3847/1538-3881/acf9ec |doi-access=free}}</ref> and 2024<ref>{{Cite journal |last1=Biddle |first1=Lauren I. |last2=Bowler |first2=Brendan P. |last3=Zhou |first3=Yifan |last4=Franson |first4=Kyle |last5=Zhang |first5=Zhoujian |date=2024-04-01 |title=Deep Paβ Imaging of the Candidate Accreting Protoplanet AB Aur b |journal=The Astronomical Journal |volume=167 |issue=4 |pages=172 |arxiv=2402.12601 |bibcode=2024AJ....167..172B |doi=10.3847/1538-3881/ad2a52 |doi-access=free |issn=0004-6256}}</ref>
|Direct imaging
|-
|[[IM Lupi]]
|
|2–3
|
|110
|
|2022<ref>{{Cite journal |last1=Verrios |first1=Harrison J. |last2=Price |first2=Daniel J. |last3=Pinte |first3=Christophe |last4=Hilder |first4=Thomas |last5=Calcino |first5=Josh |date=2022-07-01 |title=Kinematic Evidence for an Embedded Planet in the IM Lupi Disk |journal=The Astrophysical Journal |volume=934 |issue=1 |pages=L11 |arxiv=2207.02869 |bibcode=2022ApJ...934L..11V |doi=10.3847/2041-8213/ac7f44 |issn=0004-637X |doi-access=free}}</ref>
|unconfirmed candidate
|Disk Kinematics
|-
|[[HD 163296]]
|multiple?<ref>{{Cite journal |last1=Kanagawa |first1=Kazuhiro D. |last2=Ono |first2=Tomohiro |last3=Momose |first3=Munetake |date=2023-12-01 |title=Kinematic signatures of a low-mass planet with a moderately inclined orbit in a protoplanetary disk |url=https://ui.adsabs.harvard.edu/abs/2023PASJ...75.1105K |journal=Publications of the Astronomical Society of Japan |volume=75 |issue=6 |pages=1105–1123 |doi=10.1093/pasj/psad059 |arxiv=2308.12144 |bibcode=2023PASJ...75.1105K |issn=0004-6264}}</ref>
|
|
|
|
|2022<ref name=":4">{{Cite journal |last1=Calcino |first1=Josh |last2=Hilder |first2=Thomas |last3=Price |first3=Daniel J. |last4=Pinte |first4=Christophe |last5=Bollati |first5=Francesco |last6=Lodato |first6=Giuseppe |last7=Norfolk |first7=Brodie J. |date=2022-04-01 |title=Mapping the Planetary Wake in HD 163296 with Kinematics |journal=The Astrophysical Journal |volume=929 |issue=2 |pages=L25 |arxiv=2111.07416 |bibcode=2022ApJ...929L..25C |doi=10.3847/2041-8213/ac64a7 |issn=0004-637X |s2cid=244117638 |doi-access=free}}</ref>
|unconfirmed candidates
|Disk Kinematics
|-
|[[Elias 2-27|Elias 2-24]]
|
|2–5
|
|52
|
|2023<ref>{{Cite journal |last1=Pinte |first1=C. |last2=Hammond |first2=I. |last3=Price |first3=D. J. |last4=Christiaens |first4=V. |last5=Andrews |first5=S. M. |last6=Chauvin |first6=G. |last7=Pérez |first7=L. M. |last8=Jorquera |first8=S. |last9=Garg |first9=H. |last10=Norfolk |first10=B. J. |last11=Calcino |first11=J. |last12=Bonnefoy |first12=M. |date=2023-11-01 |title=Kinematic and thermal signatures of the directly imaged protoplanet candidate around Elias 2-24 |journal=Monthly Notices of the Royal Astronomical Society |volume=526 |issue=1 |pages=L41–L46 |doi=10.1093/mnrasl/slad010 |doi-access=free |arxiv=2301.08759 |bibcode=2023MNRAS.526L..41P |issn=0035-8711}}</ref>
|unconfirmed candidate
|Direct imaging + Disk Kinematics
|}