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A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf.

Rogue planets may originate from planetary systems in which they are formed and later ejected, or they can also form on their own, outside a planetary system. The Milky Way alone may have billions to trillions of rogue planets, a range the upcoming Nancy Grace Roman Space Telescope will likely be able to narrow.

Some planetary-mass objects may have formed in a similar way to stars, and the International Astronomical Union has proposed that such objects be called sub-brown dwarfs. A possible example is Cha 110913−773444, which may either have been ejected and become a rogue planet or formed on its own to become a sub-brown dwarf.

Terminology

The two first discovery papers use the names isolated planetary-mass objects (iPMO) and free-floating planets (FFP). Most astronomical papers use one of these terms. The term rogue planet is more often used for microlensing studies, which also often uses the term FFP. A press release intended for the public might use an alternative name. The discovery of at least 70 FFPs in 2021, for example, used the terms rogue planet, starless planet, wandering planet and free-floating planet in different press releases.

Discovery

Isolated planetary-mass objects (iPMO) were first discovered in 2000 by the UK team Lucas & Roche with UKIRT in the Orion Nebula. In the same year the Spanish team Zapatero Osorio et al. discovered iPMOs with Keck spectroscopy in the σ Orionis cluster. The spectroscopy of the objects in the Orion Nebula was published in 2001. Both European teams are now recognized for their quasi-simultaneous discoveries. In 1999 the Japanese team Oasa et al. discovered objects in Chamaeleon I that were spectroscopically confirmed years later in 2004 by the US team Luhman et al.

Observation

There are two techniques to discover free-floating planets: direct imaging and microlensing.

Microlensing

Astrophysicist Takahiro Sumi of Osaka University in Japan and colleagues, who form the Microlensing Observations in Astrophysics and the Optical Gravitational Lensing Experiment collaborations, published their study of microlensing in 2011. They observed 50 million stars in the Milky Way by using the 1.8-metre (5 ft 11 in) MOA-II telescope at New Zealand's Mount John Observatory and the 1.3-metre (4 ft 3 in) University of Warsaw telescope at Chile's Las Campanas Observatory. They found 474 incidents of microlensing, ten of which were brief enough to be planets of around Jupiter's size with no associated star in the immediate vicinity. The researchers estimated from their observations that there are nearly two Jupiter-mass rogue planets for every star in the Milky Way. One study suggested a much larger number, up to 100,000 times more rogue planets than stars in the Milky Way, though this study encompassed hypothetical objects much smaller than Jupiter. A 2017 study by Przemek Mróz of Warsaw University Observatory and colleagues, with six times larger statistics than the 2011 study, indicates an upper limit on Jupiter-mass free-floating or wide-orbit planets of 0.25 planets per main-sequence star in the Milky Way.

In September 2020, astronomers using microlensing techniques reported the detection, for the first time, of an Earth-mass rogue planet (named OGLE-2016-BLG-1928) unbound to any star and free floating in the Milky Way galaxy.

Direct imaging

Microlensing planets can only be studied by the microlensing event, which makes the characterization of the planet difficult. Astronomers therefore turn to isolated planetary-mass objects (iPMO) that were found via the direct imaging method. To determine a mass of a brown dwarf or iPMO one needs for example the luminosity and the age of an object. Determining the age of a low-mass object has proven to be difficult. It is no surprise that the vast majority of iPMOs are found inside young nearby star-forming regions of which astronomers know their age. These objects are younger than 200 Myrs, are massive (>5 M_J) and belong to the L- and T-dwarfs. There is however a small growing sample of cold and old Y-dwarfs that have estimated masses of 8-20 M_J. Nearby rogue planet candidates of spectral type Y include WISE 0855−0714 at a distance of 7.27±0.13 light-years. If this sample of Y-dwarfs can be characterized with more accurate measurements or if a way to better characterize their ages can be found, the number of old and cold iPMOs will likely increase significantly.

The first iPMOs were discovered in the early 2000s via direct imaging inside young star-forming regions. These iPMOs found via direct imaging formed probably like stars (sometimes called sub-brown dwarf). There might be iPMOs that form like a planet, which are then ejected. These objects will however be kinematically different from their natal star-forming region, should not be surrounded by a circumstellar disk and have high metallicity. None of the iPMOs found inside young star-forming regions show a high velocity compared to their star-forming region. For old iPMOs the cold WISE J0830+2837 shows a V_tan of about 100 km/s, which is high, but still consistent with formation in our galaxy. For WISE 1534–1043 one alternative scenario explains this object as an ejected exoplanet due to its high V_tan of about 200 km/s, but its color suggests it is an old metal-poor brown dwarf. Most astronomers studying massive iPMOs believe that they represent the low-mass end of the star-formation process.

Astronomers have used the Herschel Space Observatory and the Very Large Telescope to observe a very young free-floating planetary-mass object, OTS 44, and demonstrate that the processes characterizing the canonical star-like mode of formation apply to isolated objects down to a few Jupiter masses. Herschel far-infrared observations have shown that OTS 44 is surrounded by a disk of at least 10 Earth masses and thus could eventually form a mini planetary system. Spectroscopic observations of OTS 44 with the SINFONI spectrograph at the Very Large Telescope have revealed that the disk is actively accreting matter, similar to the disks of young stars.

Binaries

The first discovery of a resolved planetary-mass binary was 2MASS J1119–1137AB. There are however other binaries known, such as 2MASS J1553022+153236AB, WISE 1828+2650, WISE 0146+4234, WISE J0336−0143 (could also be a brown dwarf and a planetary-mass object (BD+PMO) binary), NIRISS-NGC1333-12 and several objects discovered by Zhang et al.

In the Orion Nebula a population of 40 wide binaries and 2 triple systems were discovered. This was surprising for two reasons: The trend of binaries of brown dwarfs predicted a decrease of distance between low mass objects with decreasing mass. It was also predicted that the binary fraction decreases with mass. These binaries were named Jupiter-mass binary objects (JuMBOs). They make up at least 9% of the iPMOs and have a separation smaller than 340 AU. It is unclear how these JuMBOs formed, but an extensive study argued that they formed in situ, like stars. If they formed like stars, then there must be an unknown "extra ingredient" to allow them to form. If they formed like planets and were later ejected, then it has to be explained why these binaries did not break apart during the ejection process. Future measurements with JWST might resolve if these objects formed as ejected planets or as stars. A study by Kevin Luhman reanalysed the NIRCam data and found that most JuMBOs did not appear in his sample of substellar objects. Moreover the color were consistent with reddened background sources or low signal-to-noise sources. Only JuMBO 29 is identified as a good candidate in this work. JuMBO 29 also was observed with NIRSpec and one component was identified as a young M8 source. This spectral type is consistent with a low mass for the age of the Orion Nebula.

Total number of known iPMOs

There are likely hundreds of known candidate iPMOs, over a hundred objects with spectra and a small but growing number of candidates discovered via microlensing. Some large surveys include:

As of December 2021, the largest-ever group of rogue planets was discovered, numbering at least 70 and up to 170 depending on the assumed age. They are found in the OB association between Upper Scorpius and Ophiuchus with masses between 4 and 13 M_J and age around 3 to 10 million years, and were most likely formed by either gravitational collapse of gas clouds, or formation in a protoplanetary disk followed by ejection due to dynamical instabilities. Follow-up observations with spectroscopy from the Subaru Telescope and Gran Telescopio Canarias showed that the contamination of this sample is quite low (≤6%). The 16 young objects had a mass between 3 and 14 M_J, confirming that they are indeed planetary-mass objects.

In October 2023 an even larger group of 540 planetary-mass object candidates was discovered in the Trapezium Cluster and inner Orion Nebula with JWST. The objects have a mass between 13 and 0.6 M_J. A surprising number of these objects formed wide binaries, which was not predicted.

Formation

There are in general two scenarios that can lead to the formation of an isolated planetary-mass object (iPMO). It can form like a planet around a star and is then ejected, or it forms like a low-mass star or brown dwarf in isolation. This can influence its composition and motion.

Formation like a star

Objects with a mass of at least one Jupiter mass were thought to be able to form via collapse and fragmentation of molecular clouds from models in 2001. Pre-JWST observations have shown that objects below 3-5 M_J are unlikely to form on their own. Observations in 2023 in the Trapezium Cluster with JWST have shown that objects as massive as 0.6 M_J might form on their own, not requiring a steep cut-off mass. A particular type of globule, called globulettes, are thought to be birthplaces for brown dwarfs and planetary-mass objects. Globulettes are found in the Rosette Nebula and IC 1805. Sometimes young iPMOs are still surrounded by a disk that could form exomoons. Due to the tight orbit of this type of exomoon around their host planet, they have a high chance of 10-15% to be transiting.

Disks

Some very young star-forming regions, typically younger than 5 million years, sometimes contain isolated planetary-mass objects with infrared excess and signs of accretion. Most well known is the iPMO OTS 44 discovered to have a disk and being located in Chamaeleon I. Charmaeleon I and II have other candidate iPMOs with disks. Other star-forming regions with iPMOs with disks or accretion are Lupus I, Rho Ophiuchi Cloud Complex, Sigma Orionis cluster, Orion Nebula, Taurus, NGC 1333 and IC 348. A large survey of disks around brown dwarfs and iPMOs with ALMA found that these disks are not massive enough to form earth-mass planets. There is still the possibility that the disks already have formed planets. Studies of red dwarfs have shown that some have gas-rich disks at a relative old age. These disks were dubbed Peter Pan Disks and this trend could continue into the planetary-mass regime. One Peter Pan disk is the 45 Myr old brown dwarf 2MASS J02265658-5327032 with a mass of about 13.7 M_J, which is close to the planetary-mass regime. Recent studies of the nearby planetary-mass object 2MASS J11151597+1937266 found that this nearby iPMO is surrounded by a disk. It shows signs of accretion from the disk and also infrared excess.

Formation like a planet

Ejected planets are predicted to be mostly low-mass (<30 M_E Figure 1 Ma et al.) and their mean mass depends on the mass of their host star. Simulations by Ma et al. did show that 17.5% of 1 M_☉ stars eject a total of 16.8 M_E per star with a typical (median) mass of 0.8 M_E for an individual free-floating planet (FFP). For lower mass red dwarfs with a mass of 0.3 M_☉ 12% of stars eject a total of 5.1 M_E per star with a typical mass of 0.3 M_E for an individual FFP.

Hong et al. predicted that exomoons can be scattered by planet-planet interactions and become ejected exomoons. Higher mass (0.3-1 M_J) ejected FFP are predicted to be possible, but they are also predicted to be rare. Ejection of a planet can occur via planet-planet scatter or due a stellar flyby. Another possibility is the ejection of a fragment of a disk that then forms into a planetary-mass object. Another suggested scenario is the ejection of planets in a tilted circumbinary orbit. Interactions with the central binary and the planets with each other can lead to the ejection of the lower-mass planet in the system.

Other scenarios

If a stellar or brown dwarf embryo experiences a halted accretion, it could remain low-mass enough to become a planetary-mass object. Such a halted accretion could occur if the embryo is ejected or if its circumstellar disk experiences photoevaporation near O-stars. Objects that formed via the ejected embryo scenario would have smaller or no disk and the fraction of binaries decreases for such objects. It could also be that free-floating planetary-mass objects for from a combination of scenarios.

Fate

Most isolated planetary-mass objects will float in interstellar space forever.

Some iPMOs will have a close encounter with a planetary system. This rare encounter can have three outcomes: The iPMO will remain unbound, it could be weakly bound to the star, or it could "kick out" the exoplanet, replacing it. Simulations have shown that the vast majority of these encounters result in a capture event with the iPMO being weakly bound with a low gravitational binding energy and an elongated highly eccentric orbit. These orbits are not stable and 90% of these objects gain energy due to planet-planet encounters and are ejected back into interstellar space. Only 1% of all stars will experience this temporary capture.

Warmth

Interstellar planets generate little heat and are not heated by a star. However, in 1998, David J. Stevenson theorized that some planet-sized objects adrift in interstellar space might sustain a thick atmosphere that would not freeze out. He proposed that these atmospheres would be preserved by the pressure-induced far-infrared radiation opacity of a thick hydrogen-containing atmosphere.

During planetary-system formation, several small protoplanetary bodies may be ejected from the system. An ejected body would receive less of the stellar-generated ultraviolet light that can strip away the lighter elements of its atmosphere. Even an Earth-sized body would have enough gravity to prevent the escape of the hydrogen and helium in its atmosphere. In an Earth-sized object the geothermal energy from residual core radioisotope decay could maintain a surface temperature above the melting point of water, allowing liquid-water oceans to exist. These planets are likely to remain geologically active for long periods. If they have geodynamo-created protective magnetospheres and sea floor volcanism, hydrothermal vents could provide energy for life. These bodies would be difficult to detect because of their weak thermal microwave radiation emissions, although reflected solar radiation and far-infrared thermal emissions may be detectable from an object that is less than 1,000 astronomical units from Earth. Around five percent of Earth-sized ejected planets with Moon-sized natural satellites would retain their satellites after ejection. A large satellite would be a source of significant geological tidal heating.

List

The table below lists rogue planets, confirmed or suspected, that have been discovered. It is yet unknown whether these planets were ejected from orbiting a star or else formed on their own as sub-brown dwarfs. Whether exceptionally low-mass rogue planets (such as OGLE-2012-BLG-1323 and KMT-2019-BLG-2073) are even capable of being formed on their own is currently unknown.

Discovered via direct imaging

These objects were discovered with the direct imaging method. Many were discovered in young star-clusters or stellar associations and a few old are known (such as WISE 0855−0714). List is sorted after discovery year.

Discovered via microlensing

These objects were discovered via microlensing. Rogue planets discovered via microlensing can only be studied by the lensing event. Some of them could also be exoplanets in a wide orbit around an unseen star.

Discovered via transit

See also

• Intergalactic star – Star not gravitationally bound to any galaxy
• Interstellar object – an astronomical object in interstellar space that is not gravitationally bound to a star
• ʻOumuamua – an interstellar object that passed through the Solar System in 2017
• Rogue black hole – a gravitationally unbound black hole
• Rogue extragalactic planets – rogue planets outside the Milky Way galaxy
• Tidally detached exomoon – rogue planets that were originally moons

In fiction

• A Pail of Air (1951) — a science fiction short story Fritz Leiber
• Remina (2004–2005) – horror manga by Junji Ito
• Melancholia (2011) – science fiction film by Lars von Trier
• Dark Eden (2012) – a social science fiction novel by Chris Beckett
• The Wandering Earth (2019) – a science fiction film directed by Frant Gwo
• Gemini Home Entertainment (2019–present) – horror anthology web series by Remy Abode
• Carol & the End of the World (2023) – an animated adult comedy miniseries by Dan Guterman

References

1. Shostak, Seth (24 February 2005). "Orphan Planets: It's a Hard Knock Life". Space.com. Retrieved 13 November 2020.
2. Lloyd, Robin (18 April 2001). "Free-Floating Planets – British Team Restakes Dubious Claim". Space.com. Archived from the original on 13 October 2008.
3. "Orphan 'planet' findings challenged by new model". NASA Astrobiology. 18 April 2001. Archived from the original on 22 March 2009.
4. ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Faherty, Jacqueline K.; Meisner, Aaron M.; Caselden, Dan; Schneider, Adam C.; Marocco, Federico; Cayago, Alfred J.; Smart, R. L.; Eisenhardt, Peter R.; Kuchner, Marc J.; Wright, Edward L.; Cushing, Michael C.; Allers, Katelyn N.; Bardalez Gagliuffi, Daniella C. (1 March 2021). "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs". The Astrophysical Journal Supplement Series. 253 (1): 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. ISSN 0067-0049.
5. Neil deGrasse Tyson in Cosmos: A Spacetime Odyssey as referred to by National Geographic
6. "The research team found that the mission will provide a rogue planet count that is at least 10 times more precise than current estimates, which range from tens of billions to trillions in our galaxy." https://scitechdaily.com/our-solar-system-may-be-unusual-rogue-planets-unveiled-with-nasas-roman-space-telescope/
7. Working Group on Extrasolar Planets – Definition of a "Planet" Position Statement on the Definition of a "Planet" (IAU) Archived 16 September 2006 at the Wayback Machine
8. "Rogue planet find makes astronomers ponder theory"
9. ^ Zapatero Osorio, M. R. (6 October 2000). "Discovery of Young, Isolated Planetary Mass Objects in the σ Orionis Star Cluster". Science. 290 (5489): 103–7. Bibcode:2000Sci...290..103Z. doi:10.1126/science.290.5489.103. PMID 11021788.
10. ^ Lucas, P. W.; Roche, P. F. (1 June 2000). "A population of very young brown dwarfs and free-floating planets in Orion". Monthly Notices of the Royal Astronomical Society. 314 (4): 858–864. arXiv:astro-ph/0003061. Bibcode:2000MNRAS.314..858L. doi:10.1046/j.1365-8711.2000.03515.x. ISSN 0035-8711. S2CID 119002349.
11. ^ Spezzi, L.; Alves de Oliveira, C.; Moraux, E.; Bouvier, J.; Winston, E.; Hudelot, P.; Bouy, H.; Cuillandre, J. -C. (1 September 2012). "Searching for planetary-mass T-dwarfs in the core of Serpens". Astronomy and Astrophysics. 545: A105. arXiv:1208.0702. Bibcode:2012A&A...545A.105S. doi:10.1051/0004-6361/201219559. ISSN 0004-6361. S2CID 119232214.
12. ^ Schneider, Adam C. (21 April 2016). "WISEA J114724.10-204021.3: A Free-floating Planetary Mass Member of the TW Hya Association". Astrophysical Journal Letters. 822 (1): L1. arXiv:1603.07985. Bibcode:2016ApJ...822L...1S. doi:10.3847/2041-8205/822/1/L1. S2CID 30068452.
13. ^ Liu, Michael C. (10 November 2013). "The Extremely Red, Young L Dwarf PSO J318.5338-22.8603: A Free-floating Planetary-mass Analog to Directly Imaged Young Gas-giant Planets". Astrophysical Journal Letters. 777 (1): L20. arXiv:1310.0457. Bibcode:2013ApJ...777L..20L. doi:10.1088/2041-8205/777/2/L20. S2CID 54007072.
14. Bennett, D.P.; Batista, V.; et al. (13 December 2013). "A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge". The Astrophysical Journal. 785 (2): 155. arXiv:1312.3951. Bibcode:2014ApJ...785..155B. doi:10.1088/0004-637X/785/2/155. S2CID 118327512.
15. ^ Mróz, Przemek; et al. (2020). "A Terrestrial-mass Rogue Planet Candidate Detected in the Shortest-timescale Microlensing Event". The Astrophysical Journal Letters. 903 (1). L11. arXiv:2009.12377. Bibcode:2020ApJ...903L..11M. doi:10.3847/2041-8213/abbfad.
16. ^ "ESO telescopes help uncover largest group of rogue planets yet". European Southern Observatory. 22 December 2021. Retrieved 22 December 2021.
17. "Billions of Starless Planets Haunt Dark Cloud Cradles". NAOJ: National Astronomical Observatory of Japan. 23 December 2021. Retrieved 9 September 2023.
18. ^ Shen, Zili (30 December 2021). "Wandering Planets". Astrobites. Retrieved 2 January 2022.
19. "Largest Collection of Free-Floating Planets Found in the Milky Way - KPNO". kpno.noirlab.edu. Retrieved 8 September 2023.
20. ^ Lucas, P. W.; Roche, P. F.; Allard, France; Hauschildt, P. H. (1 September 2001). "Infrared spectroscopy of substellar objects in Orion". Monthly Notices of the Royal Astronomical Society. 326 (2): 695–721. arXiv:astro-ph/0105154. Bibcode:2001MNRAS.326..695L. doi:10.1046/j.1365-8711.2001.04666.x. ISSN 0035-8711. S2CID 280663.
21. ^ Caballero, José A. (1 September 2018). "A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What?". Geosciences. 8 (10): 362. arXiv:1808.07798. Bibcode:2018Geosc...8..362C. doi:10.3390/geosciences8100362.
22. Oasa, Yumiko; Tamura, Motohide; Sugitani, Koji (1 November 1999). "A Deep Near-Infrared Survey of the Chamaeleon I Dark Cloud Core". The Astrophysical Journal. 526 (1): 336–343. Bibcode:1999ApJ...526..336O. doi:10.1086/307964. ISSN 0004-637X. S2CID 120597899.
23. Luhman, K. L.; Peterson, Dawn E.; Megeath, S. T. (1 December 2004). "Spectroscopic Confirmation of the Least Massive Known Brown Dwarf in Chamaeleon". The Astrophysical Journal. 617 (1): 565–568. arXiv:astro-ph/0411445. Bibcode:2004ApJ...617..565L. doi:10.1086/425228. ISSN 0004-637X. S2CID 18157277.
24. Homeless' Planets May Be Common in Our Galaxy Archived 8 October 2012 at the Wayback Machine by Jon Cartwright, Science Now, 18 May 2011, Accessed 20 May 2011
25. Planets that have no stars: New class of planets discovered, Physorg.com, 18 May 2011. Accessed May 2011.
26. Sumi, T.; et al. (2011). "Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing". Nature. 473 (7347): 349–352. arXiv:1105.3544. Bibcode:2011Natur.473..349S. doi:10.1038/nature10092. PMID 21593867. S2CID 4422627.
27. "Researchers say galaxy may swarm with 'nomad planets'". Stanford University. 23 February 2012. Retrieved 29 February 2012.
28. P. Mroz; et al. (2017). "No large population of unbound or wide-orbit Jupiter-mass planets". Nature. 548 (7666): 183–186. arXiv:1707.07634. Bibcode:2017Natur.548..183M. doi:10.1038/nature23276. PMID 28738410. S2CID 4459776.
29. Gough, Evan (1 October 2020). "A Rogue Earth-Mass Planet Has Been Discovered Freely Floating in the Milky Way Without a Star". Universe Today. Retrieved 2 October 2020.
30. Redd, Nola Taylor (19 October 2020). "Rogue Rocky Planet Found Adrift in the Milky Way – The diminutive world and others like it could help astronomers probe the mysteries of planet formation". Scientific American. Retrieved 19 October 2020.
31. Saumon, D.; Marley, Mark S. (1 December 2008). "The Evolution of L and T Dwarfs in Color-Magnitude Diagrams". The Astrophysical Journal. 689 (2): 1327–1344. arXiv:0808.2611. Bibcode:2008ApJ...689.1327S. doi:10.1086/592734. ISSN 0004-637X. S2CID 15981010.
32. ^ Esplin, T. L.; Luhman, K. L.; Faherty, J. K.; Mamajek, E. E.; Bochanski, J. J. (1 August 2017). "A Survey for Planetary-mass Brown Dwarfs in the Chamaeleon I Star-forming Region". The Astronomical Journal. 154 (2): 46. arXiv:1706.00058. Bibcode:2017AJ....154...46E. doi:10.3847/1538-3881/aa74e2. ISSN 0004-6256.
33. ^ Gagné, Jonathan (20 July 2015). "SDSS J111010.01+011613.1: A New Planetary-mass T Dwarf Member of the AB Doradus Moving Group". Astrophysical Journal Letters. 808 (1): L20. arXiv:1506.04195. Bibcode:2015ApJ...808L..20G. doi:10.1088/2041-8205/808/1/L20. S2CID 118834638.
34. Leggett, S. K.; Tremblin, P.; Esplin, T. L.; Luhman, K. L.; Morley, Caroline V. (1 June 2017). "The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy". The Astrophysical Journal. 842 (2): 118. arXiv:1704.03573. Bibcode:2017ApJ...842..118L. doi:10.3847/1538-4357/aa6fb5. ISSN 0004-637X.
35. Luhman, Kevin L.; Esplin, Taran L. (September 2016). "The Spectral Energy Distribution of the Coldest Known Brown Dwarf". The Astronomical Journal. 152 (2). 78. arXiv:1605.06655. Bibcode:2016AJ....152...78L. doi:10.3847/0004-6256/152/3/78. S2CID 118577918.
36. ^ Luhman, Kevin L. (10 February 2005). "Spitzer Identification of the Least Massive Known Brown Dwarf with a Circumstellar Disk". Astrophysical Journal Letters. 620 (1): L51–L54. arXiv:astro-ph/0502100. Bibcode:2005ApJ...620L..51L. doi:10.1086/428613. S2CID 15340083.
37. ^ Bardalez Gagliuffi, Daniella C.; Faherty, Jacqueline K.; Schneider, Adam C.; Meisner, Aaron; Caselden, Dan; Colin, Guillaume; Goodman, Sam; Kirkpatrick, J. Davy; Kuchner, Marc; Gagné, Jonathan; Logsdon, Sarah E. (1 June 2020). "WISEA J083011.95+283716.0: A Missing Link Planetary-mass Object". The Astrophysical Journal. 895 (2): 145. arXiv:2004.12829. Bibcode:2020ApJ...895..145B. doi:10.3847/1538-4357/ab8d25. S2CID 216553879.
38. Kirkpatrick, J. Davy; Marocco, Federico; Caselden, Dan; Meisner, Aaron M.; Faherty, Jacqueline K.; Schneider, Adam C.; Kuchner, Marc J.; Casewell, S. L.; Gelino, Christopher R.; Cushing, Michael C.; Eisenhardt, Peter R.; Wright, Edward L.; Schurr, Steven D. (1 July 2021). "The Enigmatic Brown Dwarf WISEA J153429.75-104303.3 (a.k.a. "The Accident")". The Astrophysical Journal. 915 (1): L6. arXiv:2106.13408. Bibcode:2021ApJ...915L...6K. doi:10.3847/2041-8213/ac0437. ISSN 0004-637X.
39. ^ Joergens, V.; Bonnefoy, M.; Liu, Y.; Bayo, A.; Wolf, S.; Chauvin, G.; Rojo, P. (2013). "OTS 44: Disk and accretion at the planetary border". Astronomy & Astrophysics. 558 (7): L7. arXiv:1310.1936. Bibcode:2013A&A...558L...7J. doi:10.1051/0004-6361/201322432. S2CID 118456052.
40. Dupuy, Trent J.; Liu, Michael C. (1 August 2012). "The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition". The Astrophysical Journal Supplement Series. 201 (2): 19. arXiv:1201.2465. Bibcode:2012ApJS..201...19D. doi:10.1088/0067-0049/201/2/19. ISSN 0067-0049.
41. ^ Zhang, Zhoujian; Liu, Michael C.; Best, William M. J.; Dupuy, Trent J.; Siverd, Robert J. (1 April 2021). "The Hawaii Infrared Parallax Program. V. New T-dwarf Members and Candidate Members of Nearby Young Moving Groups". The Astrophysical Journal. 911 (1): 7. arXiv:2102.05045. Bibcode:2021ApJ...911....7Z. doi:10.3847/1538-4357/abe3fa. ISSN 0004-637X.
42. Langeveld, Adam B.; Scholz, Aleks; Mužić, Koraljka; Jayawardhana, Ray; Capela, Daniel; Albert, Loïc; Doyon, René; Flagg, Laura; de Furio, Matthew; Johnstone, Doug; Lafrèniere, David; Meyer, Michael (1 October 2024). "The JWST/NIRISS Deep Spectroscopic Survey for Young Brown Dwarfs and Free-floating Planets". The Astronomical Journal. 168 (4): 179. arXiv:2408.12639. Bibcode:2024AJ....168..179L. doi:10.3847/1538-3881/ad6f0c. ISSN 0004-6256.
43. ^ Pearson, Samuel G.; McCaughrean, Mark J. (2 October 2023). "Jupiter Mass Binary Objects in the Trapezium Cluster". p. 24. arXiv:2310.01231 .
44. Portegies Zwart, Simon; Hochart, Erwan (2 July 2024). "The origin and evolution of wide Jupiter mass binary objects in young stellar clusters". SciPost. 3 (1): 19. arXiv:2312.04645. Bibcode:2024ScPA....3....1P. doi:10.21468/SciPostAstro.3.1.001.
45. ^ Luhman, K. L. (14 October 2024). "Candidates for Substellar Members of the Orion Nebula Cluster from JWST/NIRCam". arXiv:2410.10406 .
46. Luhman, K. L.; Alves de Oliveira, C.; Baraffe, I.; Chabrier, G.; Manjavacas, E.; Parker, R. J.; Tremblin, P. (13 October 2024). "JWST/NIRSpec Observations of Brown Dwarfs in the Orion Nebula Cluster". arXiv:2410.10000 .
47. ^ Miret-Roig, Núria; Bouy, Hervé; Raymond, Sean N.; Tamura, Motohide; Bertin, Emmanuel; Barrado, David; Olivares, Javier; Galli, Phillip A. B.; Cuillandre, Jean-Charles; Sarro, Luis Manuel; Berihuete, Angel (22 December 2021). "A rich population of free-floating planets in the Upper Scorpius young stellar association". Nature Astronomy. 6: 89–97. arXiv:2112.11999. Bibcode:2022NatAs...6...89M. doi:10.1038/s41550-021-01513-x. ISSN 2397-3366. S2CID 245385321. See also Nature SharedIt article link; ESO article link
48. Béjar, V. J. S.; Martín, Eduardo L. (1 January 2018). Brown Dwarfs and Free-Floating Planets in Young Stellar Clusters. Bibcode:2018haex.bookE..92B.
49. ^ Zhang, Zhoujian; Liu, Michael C.; Best, William M. J.; Dupuy, Trent J.; Siverd, Robert J. (1 April 2021). "The Hawaii Infrared Parallax Program. V. New T-dwarf Members and Candidate Members of Nearby Young Moving Groups". The Astrophysical Journal. 911 (1): 7. arXiv:2102.05045. Bibcode:2021ApJ...911....7Z. doi:10.3847/1538-4357/abe3fa. ISSN 0004-637X.
50. ^ Bouy, H.; Tamura, M.; Barrado, D.; Motohara, K.; Castro Rodríguez, N.; Miret-Roig, N.; Konishi, M.; Koyama, S.; Takahashi, H.; Huélamo, N.; Bertin, E.; Olivares, J.; Sarro, L. M.; Berihuete, A.; Cuillandre, J. -C. (1 August 2022). "Infrared spectroscopy of free-floating planet candidates in Upper Scorpius and Ophiuchus". Astronomy and Astrophysics. 664: A111. arXiv:2206.00916. Bibcode:2022A&A...664A.111B. doi:10.1051/0004-6361/202243850. ISSN 0004-6361. S2CID 249282287.
51. Raymond, Sean; Bouy, Núria Miret-Roig & Hervé (22 December 2021). "We Discovered a Rogues' Gallery of Monster-Sized Gas Giants". Nautilus. Retrieved 23 December 2021.
52. Boss, Alan P. (1 April 2001). "Formation of Planetary-Mass Objects by Protostellar Collapse and Fragmentation". The Astrophysical Journal. 551 (2): L167–L170. Bibcode:2001ApJ...551L.167B. doi:10.1086/320033. ISSN 0004-637X. S2CID 121261733.
53. Gahm, G. F.; Grenman, T.; Fredriksson, S.; Kristen, H. (1 April 2007). "Globulettes as Seeds of Brown Dwarfs and Free-Floating Planetary-Mass Objects". The Astronomical Journal. 133 (4): 1795–1809. Bibcode:2007AJ....133.1795G. doi:10.1086/512036. ISSN 0004-6256. S2CID 120588285.
54. ^ Limbach, Mary Anne; Vos, Johanna M.; Winn, Joshua N.; Heller, René; Mason, Jeffrey C.; Schneider, Adam C.; Dai, Fei (1 September 2021). "On the Detection of Exomoons Transiting Isolated Planetary-mass Objects". The Astrophysical Journal. 918 (2): L25. arXiv:2108.08323. Bibcode:2021ApJ...918L..25L. doi:10.3847/2041-8213/ac1e2d. ISSN 0004-637X.
55. Luhman, K. L.; Adame, Lucía; D'Alessio, Paola; Calvet, Nuria; Hartmann, Lee; Megeath, S. T.; Fazio, G. G. (1 December 2005). "Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk". The Astrophysical Journal. 635 (1): L93–L96. arXiv:astro-ph/0511807. Bibcode:2005ApJ...635L..93L. doi:10.1086/498868. ISSN 0004-637X.
56. ^ Jayawardhana, Ray; Ivanov, Valentin D. (1 August 2006). "Spectroscopy of Young Planetary Mass Candidates with Disks". The Astrophysical Journal. 647 (2): L167–L170. arXiv:astro-ph/0607152. Bibcode:2006ApJ...647L.167J. doi:10.1086/507522. ISSN 0004-637X.
57. ^ Rilinger, Anneliese M.; Espaillat, Catherine C. (1 November 2021). "Disk Masses and Dust Evolution of Protoplanetary Disks around Brown Dwarfs". The Astrophysical Journal. 921 (2): 182. arXiv:2106.05247. Bibcode:2021ApJ...921..182R. doi:10.3847/1538-4357/ac09e5. ISSN 0004-637X.
58. Zapatero Osorio, M. R.; Caballero, J. A.; Béjar, V. J. S.; Rebolo, R.; Barrado Y Navascués, D.; Bihain, G.; Eislöffel, J.; Martín, E. L.; Bailer-Jones, C. A. L.; Mundt, R.; Forveille, T.; Bouy, H. (1 September 2007). "Discs of planetary-mass objects in σ Orionis". Astronomy and Astrophysics. 472 (1): L9–L12. Bibcode:2007A&A...472L...9Z. doi:10.1051/0004-6361:20078116. ISSN 0004-6361.
59. ^ Fang, Min; Kim, Jinyoung Serena; Pascucci, Ilaria; Apai, Dániel; Manara, Carlo Felice (1 December 2016). "A Candidate Planetary-mass Object with a Photoevaporating Disk in Orion". The Astrophysical Journal Letters. 833 (2): L16. arXiv:1611.09761. Bibcode:2016ApJ...833L..16F. doi:10.3847/2041-8213/833/2/L16. ISSN 0004-637X.
60. Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Bowler, Brendan P.; Aller, Kimberly M.; Zhang, Zhoujian; Kotson, Michael C.; Burgett, W. S.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Metcalfe, N.; Wainscoat, R. J. (1 March 2017). "A Search for L/T Transition Dwarfs with Pan-STARRS1 and WISE. III. Young L Dwarf Discoveries and Proper Motion Catalogs in Taurus and Scorpius-Centaurus". The Astrophysical Journal. 837 (1): 95. arXiv:1702.00789. Bibcode:2017ApJ...837...95B. doi:10.3847/1538-4357/aa5df0. hdl:1721.1/109753. ISSN 0004-637X.
61. Scholz, Aleks; Muzic, Koraljka; Jayawardhana, Ray; Almendros-Abad, Victor; Wilson, Isaac (1 May 2023). "Disks around Young Planetary-mass Objects: Ultradeep Spitzer Imaging of NGC 1333". The Astronomical Journal. 165 (5): 196. arXiv:2303.12451. Bibcode:2023AJ....165..196S. doi:10.3847/1538-3881/acc65d. hdl:10023/27429. ISSN 0004-6256.
62. Alves de Oliveira, C.; Moraux, E.; Bouvier, J.; Duchêne, G.; Bouy, H.; Maschberger, T.; Hudelot, P. (1 January 2013). "Spectroscopy of brown dwarf candidates in IC 348 and the determination of its substellar IMF down to planetary masses". Astronomy and Astrophysics. 549: A123. arXiv:1211.4029. Bibcode:2013A&A...549A.123A. doi:10.1051/0004-6361/201220229. ISSN 0004-6361.
63. Boucher, Anne; Lafrenière, David; Gagné, Jonathan; Malo, Lison; Faherty, Jacqueline K.; Doyon, René; Chen, Christine H. (1 November 2016). "BANYAN. VIII. New Low-mass Stars and Brown Dwarfs with Candidate Circumstellar Disks". The Astrophysical Journal. 832 (1): 50. arXiv:1608.08259. Bibcode:2016ApJ...832...50B. doi:10.3847/0004-637X/832/1/50. ISSN 0004-637X.
64. Theissen, Christopher A.; Burgasser, Adam J.; Bardalez Gagliuffi, Daniella C.; Hardegree-Ullman, Kevin K.; Gagné, Jonathan; Schmidt, Sarah J.; West, Andrew A. (1 January 2018). "2MASS J11151597+1937266: A Young, Dusty, Isolated, Planetary-mass Object with a Potential Wide Stellar Companion". The Astrophysical Journal. 853 (1): 75. arXiv:1712.03964. Bibcode:2018ApJ...853...75T. doi:10.3847/1538-4357/aaa0cf. ISSN 0004-637X.
65. ^ Ma, Sizheng; Mao, Shude; Ida, Shigeru; Zhu, Wei; Lin, Douglas N. C. (1 September 2016). "Free-floating planets from core accretion theory: microlensing predictions". Monthly Notices of the Royal Astronomical Society. 461 (1): L107–L111. arXiv:1605.08556. Bibcode:2016MNRAS.461L.107M. doi:10.1093/mnrasl/slw110. ISSN 0035-8711.
66. Hong, Yu-Cian; Raymond, Sean N.; Nicholson, Philip D.; Lunine, Jonathan I. (1 January 2018). "Innocent Bystanders: Orbital Dynamics of Exomoons During Planet-Planet Scattering". The Astrophysical Journal. 852 (2): 85. arXiv:1712.06500. Bibcode:2018ApJ...852...85H. doi:10.3847/1538-4357/aaa0db. ISSN 0004-637X.
67. ^ Miret-Roig, Núria (1 March 2023). "The origin of free-floating planets". Astrophysics and Space Science. 368 (3): 17. arXiv:2303.05522. Bibcode:2023Ap&SS.368...17M. doi:10.1007/s10509-023-04175-5. ISSN 0004-640X.
68. Chen, Cheng; Martin, Rebecca G.; Lubow, Stephen H.; Nixon, C. J. (1 January 2024). "Tilted Circumbinary Planetary Systems as Efficient Progenitors of Free-floating Planets". The Astrophysical Journal. 961 (1): L5. arXiv:2310.15603. Bibcode:2024ApJ...961L...5C. doi:10.3847/2041-8213/ad17c5. ISSN 0004-637X.
69. Goulinski, Nadav; Ribak, Erez N. (1 January 2018). "Capture of free-floating planets by planetary systems". Monthly Notices of the Royal Astronomical Society. 473 (2): 1589–1595. arXiv:1705.10332. Bibcode:2018MNRAS.473.1589G. doi:10.1093/mnras/stx2506. ISSN 0035-8711.
70. Raymond, Sean (9 April 2005). "Life in the dark". Aeon. Retrieved 9 April 2016.
71. ^ Stevenson, David J.; Stevens, C. F. (1999). "Life-sustaining planets in interstellar space?". Nature. 400 (6739): 32. Bibcode:1999Natur.400...32S. doi:10.1038/21811. PMID 10403246. S2CID 4307897.
72. Lissauer, J. J. (1987). "Timescales for Planetary Accretion and the Structure of the Protoplanetary disk". Icarus. 69 (2): 249–265. Bibcode:1987Icar...69..249L. doi:10.1016/0019-1035(87)90104-7. hdl:2060/19870013947.
73. Abbot, Dorian S.; Switzer, Eric R. (2 June 2011). "The Steppenwolf: A proposal for a habitable planet in interstellar space". The Astrophysical Journal. 735 (2): L27. arXiv:1102.1108. Bibcode:2011ApJ...735L..27A. doi:10.1088/2041-8205/735/2/L27. S2CID 73631942.
74. Debes, John H.; Steinn Sigurðsson (20 October 2007). "The Survival Rate of Ejected Terrestrial Planets with Moons". The Astrophysical Journal Letters. 668 (2): L167–L170. arXiv:0709.0945. Bibcode:2007ApJ...668L.167D. doi:10.1086/523103. S2CID 15782213.
75. Luhman, Kevin L. (10 December 2005). "Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk". Astrophysical Journal Letters. 635 (1): L93–L96. arXiv:astro-ph/0511807. Bibcode:2005ApJ...635L..93L. doi:10.1086/498868. S2CID 11685964.
76. Artigau, Étienne; Doyon, René; Lafrenière, David; Nadeau, Daniel; Robert, Jasmin; Albert, Loïc (n.d.). "Discovery of the Brightest T Dwarf in the Northern Hemisphere". The Astrophysical Journal Letters. 651 (1): L57. arXiv:astro-ph/0609419. Bibcode:2006ApJ...651L..57A. doi:10.1086/509146. ISSN 1538-4357. S2CID 118943169.
77. Gagné, Jonathan; Faherty, Jacqueline K.; Burgasser, Adam J.; Artigau, Étienne; Bouchard, Sandie; Albert, Loïc; Lafrenière, David; Doyon, René; Bardalez-Gagliuffi, Daniella C. (15 May 2017). "SIMP J013656.5+093347 is Likely a Planetary-Mass Object in the Carina-Near Moving Group". The Astrophysical Journal. 841 (1): L1. arXiv:1705.01625. Bibcode:2017ApJ...841L...1G. doi:10.3847/2041-8213/aa70e2. ISSN 2041-8213. S2CID 119024210.
78. ^ Sanghi, Aniket; Liu, Michael C.; Best, William M.; Dupuy, Trent J.; Siverd, Robert J.; Zhang, Zhoujian; Hurt, Spencer A.; Magnier, Eugene A.; Aller, Kimberly M.; Deacon, Niall R. (6 September 2023). "The Hawaii Infrared Parallax Program. VI. The Fundamental Properties of 1000+ Ultracool Dwarfs and Planetary-mass Objects Using Optical to Mid-IR SEDs and Comparison to BT-Settl and ATMO 2020 Model Atmospheres". arXiv:2309.03082 .
79. ^ Sanghi, Aniket; Liu, Michael C.; Best, William M.; Dupuy, Trent J.; Siverd, Robert J.; Zhang, Zhoujian; Hurt, Spencer A.; Magnier, Eugene A.; Aller, Kimberly M.; Deacon, Niall R. (7 September 2023). "Table of Ultracool Fundamental Properties". Zenodo: 1. doi:10.5281/zenodo.8315643.
80. Marsh, Kenneth A. (1 February 2010). "A Young Planetary-Mass Object in the ρ Oph Cloud Core". Astrophysical Journal Letters. 709 (2): L158–L162. arXiv:0912.3774. Bibcode:2010ApJ...709L.158M. doi:10.1088/2041-8205/709/2/L158. S2CID 29098549.
81. ^ Beichman, C.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Barman, Travis S.; Marsh, Kenneth A.; Cushing, Michael C.; Wright, E. L. (2013). "The Coldest Brown Dwarf (or Free-floating Planet)?: The Y Dwarf WISE 1828+2650". The Astrophysical Journal. 764 (1): 101. arXiv:1301.1669. Bibcode:2013ApJ...764..101B. doi:10.1088/0004-637X/764/1/101. S2CID 118575478.
82. Delorme, Philippe (25 September 2012). "CFBDSIR2149-0403: a 4-7 Jupiter-mass free-floating planet in the young moving group AB Doradus?". Astronomy & Astrophysics. 548A: 26. arXiv:1210.0305. Bibcode:2012A&A...548A..26D. doi:10.1051/0004-6361/201219984. S2CID 50935950.
83. Scholz, Alexander; Jayawardhana, Ray; Muzic, Koraljka; Geers, Vincent; Tamura, Motohide; Tanaka, Ichi (1 September 2012). "Substellar Objects in Nearby Young Clusters (SONYC). VI. The Planetary-mass Domain of NGC 1333". The Astrophysical Journal. 756 (1): 24. arXiv:1207.1449. Bibcode:2012ApJ...756...24S. doi:10.1088/0004-637X/756/1/24. ISSN 0004-637X. S2CID 119251742.
84. "NAME Serpens Cluster". simbad.cds.unistra.fr. Retrieved 7 September 2023.
85. Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (1 September 2015). "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime". The Astrophysical Journal. 810 (2): 158. arXiv:1508.01767. Bibcode:2015ApJ...810..158F. doi:10.1088/0004-637X/810/2/158. ISSN 0004-637X. S2CID 89611607.
86. Gagné, Jonathan (10 March 2014). "BANYAN. II. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups with Previously Known Signs of Youth". Astrophysical Journal. 783 (2): 121. arXiv:1312.5864. Bibcode:2014ApJ...783..121G. doi:10.1088/0004-637X/783/2/121. S2CID 119251619.
87. Schneider, Adam C. (9 January 2014). "Discovery of the Young L Dwarf WISE J174102.78-464225.5". Astronomical Journal. 147 (2): 34. arXiv:1311.5941. Bibcode:2014AJ....147...34S. doi:10.1088/0004-6256/147/2/34. S2CID 38602758.
88. Zapatero Osorio, M. R.; Lodieu, N.; Béjar, V. J. S.; Martín, Eduardo L.; Ivanov, V. D.; Bayo, A.; Boffin, H. M. J.; Muzic, K.; Minniti, D.; Beamín, J. C. (1 August 2016). "Near-infrared photometry of WISE J085510.74-071442.5". Astronomy and Astrophysics. 592: A80. arXiv:1605.08620. Bibcode:2016A&A...592A..80Z. doi:10.1051/0004-6361/201628662. ISSN 0004-6361.
89. Luhman, Kevin L. (10 May 2014). "Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun". Astrophysical Journal Letters. 786 (2): L18. arXiv:1404.6501. Bibcode:2014ApJ...786L..18L. doi:10.1088/2041-8205/786/2/L18. S2CID 119102654.
90. Gagné, Jonathan; Gonzales, Eileen C.; Faherty, Jacqueline K. (2018). "A Gaia DR2 Confirmation that 2MASS J12074836-3900043 is a Member of the TW Hya Association". Research Notes of the American Astronomical Society. 2 (2): 17. arXiv:1804.09625. Bibcode:2018RNAAS...2...17G. doi:10.3847/2515-5172/aac0fd.
91. Gagné, Jonathan; Gonzales, Eileen C.; Faherty, Jacqueline K. (1 May 2018). "A Gaia DR2 Confirmation that 2MASS J12074836–3900043 is a Member of the TW HYA Association". Research Notes of the AAS. 2 (2): 17. arXiv:1804.09625. Bibcode:2018RNAAS...2...17G. doi:10.3847/2515-5172/aac0fd. ISSN 2515-5172.
92. Gagné, Jonathan (10 April 2014). "The Coolest Isolated Brown Dwarf Candidate Member of TWA". Astrophysical Journal Letters. 785 (1): L14. arXiv:1403.3120. Bibcode:2014ApJ...785L..14G. doi:10.1088/2041-8205/785/1/L14. S2CID 119269921.
93. Liu, Michael C. (9 December 2016). "The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs". Astrophysical Journal. 833 (1): 96. arXiv:1612.02426. Bibcode:2016ApJ...833...96L. doi:10.3847/1538-4357/833/1/96. S2CID 119192984.
94. Gagné, Jonathan (1 September 2014). "SIMP J2154-1055: A New Low-gravity L4β Brown Dwarf Candidate Member of the Argus Association". Astrophysical Journal Letters. 792 (1): L17. arXiv:1407.5344. Bibcode:2014ApJ...792L..17G. doi:10.1088/2041-8205/792/1/L17. S2CID 119118880.
95. Kellogg, Kendra (11 April 2016). "The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog". Astrophysical Journal Letters. 821 (1): L15. arXiv:1603.08529. Bibcode:2016ApJ...821L..15K. doi:10.3847/2041-8205/821/1/L15. S2CID 119289711.
96. Peña Ramírez, K.; Béjar, V. J. S.; Zapatero Osorio, M. R. (1 February 2016). "A new free-floating planet in the Upper Scorpius association". Astronomy and Astrophysics. 586: A157. arXiv:1511.05586. Bibcode:2016A&A...586A.157P. doi:10.1051/0004-6361/201527425. ISSN 0004-6361. S2CID 55940316.
97. Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Bowler, Brendan P.; Aller, Kimberly M.; Zhang, Zhoujian; Kotson, Michael C.; Burgett, W. S.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Metcalfe, N.; Wainscoat, R. J. (1 March 2017). "A Search for L/T Transition Dwarfs with Pan-STARRS1 and WISE. III. Young L Dwarf Discoveries and Proper Motion Catalogs in Taurus and Scorpius-Centaurus". The Astrophysical Journal. 837 (1): 95. arXiv:1702.00789. Bibcode:2017ApJ...837...95B. doi:10.3847/1538-4357/aa5df0. ISSN 0004-637X.
98. Zapatero Osorio, M. R.; Béjar, V. J. S.; Lodieu, N.; Manjavacas, E. (1 March 2018). "Confirming the least massive members of the Pleiades star cluster". Monthly Notices of the Royal Astronomical Society. 475 (1): 139–153. arXiv:1712.01698. Bibcode:2018MNRAS.475..139Z. doi:10.1093/mnras/stx3154. ISSN 0035-8711.
99. Gagné, Jonathan; Allers, Katelyn N.; Theissen, Christopher A.; Faherty, Jacqueline K.; Bardalez Gagliuffi, Daniella; Artigau, Étienne (1 February 2018). "2MASS J13243553+6358281 Is an Early T-type Planetary-mass Object in the AB Doradus Moving Group". The Astrophysical Journal. 854 (2): L27. arXiv:1802.00493. Bibcode:2018ApJ...854L..27G. doi:10.3847/2041-8213/aaacfd. ISSN 0004-637X.
100. Vos, Johanna M.; Faherty, Jacqueline K.; Gagné, Jonathan; Marley, Mark; Metchev, Stanimir; Gizis, John; Rice, Emily L.; Cruz, Kelle (2022). "Let the Great World Spin: Revealing the Stormy, Turbulent Nature of Young Giant Exoplanet Analogs with the Spitzer Space Telescope". The Astrophysical Journal. 924 (2): 68. arXiv:2201.04711. Bibcode:2022ApJ...924...68V. doi:10.3847/1538-4357/ac4502. S2CID 245904001.
101. "The Extrasolar Planet Encyclopaedia – 2MASS J0718-6415". Extrasolar Planets Encyclopaedia. Retrieved 31 January 2021.
102. Schneider, Adam C.; Burgasser, Adam J.; Bruursema, Justice; Munn, Jeffrey A.; Vrba, Frederick J.; Caselden, Dan; Kabatnik, Martin; Rothermich, Austin; Sainio, Arttu; Bickle, Thomas P.; Dahm, Scott E.; Meisner, Aaron M.; Kirkpatrick, J. Davy; Suárez, Genaro; Gagné, Jonathan (1 February 2023). "Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf". The Astrophysical Journal. 943 (2): L16. arXiv:2301.02322. Bibcode:2023ApJ...943L..16S. doi:10.3847/2041-8213/acb0cd. ISSN 0004-637X. S2CID 255522681.
103. ^ Mróz, Przemek; Poleski, Radosław; Gould, Andrew; Udalski, Andrzej; Sumi, Takahiro; Szymański, Michał K.; Soszyński, Igor; Pietrukowicz, Paweł; Kozłowski, Szymon; Skowron, Jan; Ulaczyk, Krzysztof; Albrow, Michael D.; Chung, Sun-Ju; Han, Cheongho; Hwang, Kyu-Ha; Jung, Youn Kil; Kim, Hyoun-Woo; Ryu, Yoon-Hyun; Shin, In-Gu; Shvartzvald, Yossi; Yee, Jennifer C.; Zang, Weicheng; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; et al. (2020), "A terrestrial-mass rogue planet candidate detected in the shortest-timescale microlensing event", The Astrophysical Journal, 903 (1): L11, arXiv:2009.12377, Bibcode:2020ApJ...903L..11M, doi:10.3847/2041-8213/abbfad, S2CID 221971000
104. Mróz, Przemek; Udalski, Andrzej; Bennett, David P.; Ryu, Yoon-Hyun; Sumi, Takahiro; Shvartzvald, Yossi; Skowron, Jan; Poleski, Radosław; Pietrukowicz, Paweł; Kozłowski, Szymon; Szymański, Michał K.; Wyrzykowski, Łukasz; Soszyński, Igor; Ulaczyk, Krzysztof; Rybicki, Krzysztof (1 February 2019). "Two new free-floating or wide-orbit planets from microlensing". Astronomy and Astrophysics. 622: A201. arXiv:1811.00441. Bibcode:2019A&A...622A.201M. doi:10.1051/0004-6361/201834557. ISSN 0004-6361.
105. ^ Becky Ferreira (9 November 2018). "Rare Sighting of Two Rogue Planets That Do Not Orbit Stars". Motherboard. Retrieved 10 February 2019.
106. ^ Jake Parks (16 November 2018). "These Two New 'Rogue Planets' Wander the Cosmos Without Stars". Discover Magazine. Archived from the original on 16 November 2018. Retrieved 10 February 2019.
107. ^ Jake Parks (15 November 2018). "Two free-range planets found roaming the Milky Way in solitude". Astronomy Magazine. Retrieved 10 February 2019.
108. "Exoplanet-catalog". Exoplanet Exploration: Planets Beyond our Solar System. Retrieved 4 January 2021.
109. Miyazaki, S.; Sumi, T.; Bennett, D. P.; Gould, A.; Udalski, A.; Bond, I. A.; Koshimoto, N.; Nagakane, M.; Rattenbury, N.; Abe, F.; Bhattacharya, A.; Barry, R.; Donachie, M.; Fukui, A.; Hirao, Y. (1 September 2018). "MOA-2015-BLG-337: A Planetary System with a Low-mass Brown Dwarf/Planetary Boundary Host, or a Brown Dwarf Binary". The Astronomical Journal. 156 (3): 136. arXiv:1804.00830. Bibcode:2018AJ....156..136M. doi:10.3847/1538-3881/aad5ee. ISSN 0004-6256.
110. Kim, Hyoun-Woo; Hwang, Kyu-Ha; Gould, Andrew; Yee, Jennifer C.; Ryu, Yoon-Hyun; Albrow, Michael D.; Chung, Sun-Ju; Han, Cheongho; Jung, Youn Kil; Lee, Chung-Uk; Shin, In-Gu; Shvartzvald, Yossi; Zang, Weicheng; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Seung-Lee; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W. (2021). "KMT-2019-BLG-2073: Fourth Free-floating Planet Candidate with θ e < 10 μas". The Astronomical Journal. 162 (1): 15. arXiv:2007.06870. Bibcode:2021AJ....162...15K. doi:10.3847/1538-3881/abfc4a. S2CID 235445277.
111. ^ Mróz, Przemek; et al. (2020), "A Free-floating or Wide-orbit Planet in the Microlensing Event OGLE-2019-BLG-0551", The Astronomical Journal, 159 (6): 262, arXiv:2003.01126, Bibcode:2020AJ....159..262M, doi:10.3847/1538-3881/ab8aeb, S2CID 211817861
112. Kaczmarek, Zofia; McGill, Peter; Evans, N. Wyn; Smith, Leigh C.; Wyrzykowski, Łukasz; Howil, Kornel; Jabłońska, Maja (1 August 2022). "Dark lenses through the dust: parallax microlensing events in the VVV". Monthly Notices of the Royal Astronomical Society. 514 (4): 4845–4860. arXiv:2205.07922. Bibcode:2022MNRAS.514.4845K. doi:10.1093/mnras/stac1507. ISSN 0035-8711.
113. ^ Koshimoto, Naoki; Sumi, Takahiro; Bennett, David P.; Bozza, Valerio; Mróz, Przemek; Udalski, Andrzej; Rattenbury, Nicholas J.; Abe, Fumio; Barry, Richard; Bhattacharya, Aparna; Bond, Ian A.; Fujii, Hirosane; Fukui, Akihiko; Hamada, Ryusei; Hirao, Yuki (14 March 2023). "Terrestrial and Neptune mass free-floating planet candidates from the MOA-II 9-year Galactic Bulge survey". The Astronomical Journal. 166 (3): 107. arXiv:2303.08279. Bibcode:2023AJ....166..107K. doi:10.3847/1538-3881/ace689.
114. ^ Kenworthy, M. A.; Klaassen, P. D.; et al. (January 2020). "ALMA and NACO observations towards the young exoring transit system J1407 (V1400 Cen)". Astronomy & Astrophysics. 633: A115. arXiv:1912.03314. Bibcode:2020A&A...633A.115K. doi:10.1051/0004-6361/201936141.

Bibliography

• "Possibility of Life Sustaining Planets in Interstellar Space" Article by Stevenson similar to the Nature article but with more information.

External links

• Definition of a "Planet" (Resolution B5 – IAU)
• Strange New Worlds Could Make Miniature Solar Systems Robert Roy Britt (SPACE.com) 5 June 2006 11:35 am ET
• The IAU draft definition of "planet" and "plutons" press release (International Astronomical Union) 2006

v t e Exoplanets
Planet Definition IAU Planetary science
Main topics	Exoplanet Exoplanet orbital and physical parameters Methods of detecting exoplanets Planetary system Planet-hosting stars
Sizes and types	Terrestrial Carbon planet Coreless planet Desert planet Dwarf planet Hycean planet Ice planet Iron planet (Super-Mercury) Lava planet Ocean world Mega-Earth Sub-Earth Super-Earth Gaseous Eccentric Jupiter Mini-Neptune (Gas dwarf) Helium planet Hot Jupiter Hot Neptune Gas giant Ice giant Super-Jupiter Super-Neptune Super-puff Ultra-hot Jupiter Ultra-hot Neptune Other types Blanet Brown dwarf Chthonian planet Circumbinary planet Circumtriple planet Disrupted planet Double planet Ecumenopolis Eyeball planet Giant planet Mesoplanet Planemo Planet/Brown dwarf boundary Planetesimal Protoplanet Pulsar planet Sub-brown dwarf Sub-Neptune Toroidal planet Ultra-cool dwarf Ultra-short period planet (USP)
Formation and evolution	Accretion Accretion disk Asteroid belt Circumplanetary disk Circumstellar disc Circumstellar envelope Cosmic dust Debris disk Detached object Disrupted planet Excretion disk Exozodiacal dust Extraterrestrial materials Extraterrestrial sample curation Giant-impact hypothesis Gravitational collapse Hills cloud Internal structure Interplanetary dust cloud Interplanetary medium Interplanetary space Interstellar cloud Interstellar dust Interstellar medium Interstellar space Kuiper belt List of interstellar and circumstellar molecules Merging stars Molecular cloud Nebular hypothesis Oort cloud Outer space Planetary migration Planetary system Planetesimal Planet formation Protoplanetary disk Ring system Rubble pile Sample-return mission Scattered disc Star formation
Systems	Exocomet Interstellar Exomoon Tidally detached Rogue planet Orbits Retrograde Trojan Mean-motion resonances Titius–Bode law
Host stars	A B Binary star Brown dwarfs F/Yellow-white dwarfs G/Yellow dwarfs Herbig Ae/Be K/Orange dwarfs M/Red dwarfs Pulsar Red giant Subdwarf B Subgiant T Tauri White dwarfs Yellow giants
Detection	Astrometry Direct imaging list Microlensing list Polarimetry Timing list Radial velocity list Transit method list Transit-timing variation
Habitability	Astrobiology Astrooceanography Circumstellar habitable zone Earth analog Extraterrestrial liquid water Galactic habitable zone Habitability of binary star systems Habitability of F-type main-sequence star systems Habitability of K-type main-sequence star systems Habitability of natural satellites Habitability of neutron star systems Habitability of red dwarf systems Habitability of yellow dwarf systems Habitable zone for complex life List of potentially habitable exoplanets Tholin Superhabitable planet
Catalogues	Nearby Habitable Systems Exoplanet Data Explorer Extrasolar Planets Encyclopaedia NASA Exoplanet Archive NASA Star and Exoplanet Database Open Exoplanet Catalogue
Lists	Exoplanetary systems Host stars Multiplanetary systems Stars with proto-planetary discs Exoplanets Discoveries Extremes Firsts Nearest Largest Heaviest Terrestrial candidates Kepler 1–500 501–1000 1001–1500 1501–2000 K2 Potentially habitable Proper names Discovered exoplanets by year before 2000 2000–2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Other	Carl Sagan Institute Exoplanet naming convention Exoplanet phase curves Exoplanetary Circumstellar Environments and Disk Explorer Extragalactic planet Extrasolar planets in fiction Geodynamics of terrestrial exoplanets Neptunian desert Nexus for Exoplanet System Science Planets in globular clusters Small planet radius gap Sudarsky's gas giant classification
Discoveries of exoplanets Search projects

• Astronomy
• Stars
• Outer space

• Planetary-mass objects
• Rogue planets
• Space hazards
• Types of planet