Cha 1107−7626
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 11h 07m 07.72512s |
| Declination | −76° 26′ 32.5176″ |
| Characteristics | |
| Evolutionary stage | planetary-mass brown dwarf |
| Spectral type | L0 ±1[1] |
| Apparent magnitude (J) | 17.61 ±0.03[1] |
| Apparent magnitude (H) | 16.80 ±0.03[1] |
| Apparent magnitude (Ks) | 15.91 ±0.02[1] |
| Astrometry | |
| Proper motion (μ) | RA: −13.8 ±0.8 mas/yr[2] Dec.: −0.4 ±3.2 mas/yr[2] |
| Distance | ~620 ly (~190 pc)[3] |
| Details[3][1] | |
| Mass | 6−10 MJup |
| Luminosity (bolometric) | 0.00033 L☉ |
| Surface gravity (log g) | 3.5 cgs |
| Temperature | 1900 ±100 K |
| Age | 1−5 Myr |
| Other designations | |
| WISE J110707.72-762632.5, WISEA J110707.69-762632.5, [L2007b] Cha J11070768-7626326 | |
| Database references | |
| SIMBAD | data |
Cha 1107−7626 (Cha J11070768−7626326) is a free-floating planetary-mass object in the Chamaeleon I star-forming region, about 190 parsecs (620 ly) distant from the Solar System. It is the lowest-mass object with hydrocarbons detected in its disk (as of May 2025).[3] The object is located north-west of IC 2631.[4]
Cha 1107−7626 was discovered in 2008 by Kevin Luhman et al. with the Spitzer Space Telescope and the Magellan II telescope. The researchers estimated a spectral type of L0, due to it having weaker TiO and VO absorption compared compared to other low-mass members of the Chamaeleon I region, such as OTS 44 and Cha 110913−773444. Initially the mass was estimated to be 0.004-0.01 M☉ (4.2-10.5 MJ).[1] A work by Laura Flagg et al. (2025) observed the object with the JWST instruments NIRSpec and MIRI. This work refined the mass of Cha 1107−7626 to 6-10 MJ. It also detected hydrocarbons in the disk of this planetary-mass object.[3]
The circumstellar disk
[edit]The Spitzer photometry showed an infrared excess, which indicated that the object is surrounded by a circumplanetary disk. The optical spectrum with Magellan/LDSS-3 showed strong H-alpha emission, indicating the planetary-mass object is actively accreting hydrogen gas from the surrounding disk.[1] New and archived observations with JWST, Magellan and VLT/SINFONI[5][3] were used to study the disk in more detail. The VLT spectrum showed Paschen-beta line, which is also a sign for active accretion. The rate at which Cha 1107−7626 accretes material from the disk was estimated to be between 10-10 and 10-11 solar masses per year (or the mass of 2 Pallas per year, or less). The MIRI low-resolution spectrum shows spectral features that match emission by methane and ethylene, as well as hints of emission by ethane. Hydrocarbons are also very common in disks around young very low-mass stars, and the mid-infrared spectrum was found to be very similar to the low-mass star ISO-ChaI 147, located in the same star-forming region. These similarities hint at similar processes in disks around young objects with different masses and isolated planetary-mass objects might be able to form their own miniature planetary systems.[3] For low-mass objects, such as WISEA J044634.16-262756.1, it is suggested that the carbon-rich gases could lead to carbon-rich atmospheres, similar to Titan. Additionally it could lead to carbon-poor solids on planets, if the planets are assembled from solids at a late stage. These solids lose their carbon to the gas-phase of the disk.[6]
See also
[edit]Other free-floating planetary-mass objects with disks
- 2MASS J11151597+1937266
- J1407b, could also orbit a star
- KPNO-Tau 12
Other planetary-mass objects with disks that bound to a star
References
[edit]- ^ a b c d e f g Luhman, K. L.; Allen, L. E.; Allen, P. R.; Gutermuth, R. A.; Hartmann, L.; Mamajek, E. E.; Megeath, S. T.; Myers, P. C.; Fazio, G. G. (March 2008). "The Disk Population of the Chamaeleon I Star-forming Region". The Astrophysical Journal. 675 (2): 1375–1406. arXiv:0803.1019. Bibcode:2008ApJ...675.1375L. doi:10.1086/527347. ISSN 0004-637X.
- ^ Esplin, T. L.; Luhman, K. L.; Faherty, J. K.; Mamajek, E. E.; Bochanski, J. J. (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.
- ^ a b c d e f Flagg, Laura; Scholz, Aleks; Almendros-Abad, V.; Jayawardhana, Ray; Damian, Belinda; Muzic, Koraljka; Natta, Antonella; Pinilla, Paola; Testi, Leonardo (2025). "Detection of Hydrocarbons in the Disk around an Actively-Accreting Planetary-Mass Object". arXiv:2505.13714 [astro-ph.EP].
- ^ "Legacy Survey Sky Browser". www.legacysurvey.org. Retrieved 2025-06-01.
- ^ Almendros-Abad, V.; Mužić, K.; Moitinho, A.; Krone-Martins, A.; Kubiak, K. (January 2022). "Youth analysis of near-infrared spectra of young low-mass stars and brown dwarfs". Astronomy and Astrophysics. 657: A129. arXiv:2110.06368. Bibcode:2022A&A...657A.129A. doi:10.1051/0004-6361/202142050. ISSN 0004-6361.
- ^ Long 龙, Feng 凤.; Pascucci, Ilaria; Houge, Adrien; Banzatti, Andrea; Pontoppidan, Klaus M.; Najita, Joan; Krijt, Sebastiaan; Xie, Chengyan; Williams, Joe; Herczeg 沈, Gregory J. 雷歌; Andrews, Sean M.; Bergin, Edwin; Blake, Geoffrey A.; Colmenares, María José; Harsono, Daniel; Romero-Mirza, Carlos E.; Li 李, Rixin 日新; Lu, Cicero X.; Pinilla, Paola; Wilner, David J.; Vioque, Miguel; Zhang, Ke; JDISCS Collaboration (2025). "The First JWST View of a 30-Myr-old Protoplanetary Disk Reveals a Late-stage Carbon-rich Phase". The Astrophysical Journal Letters. 978 (2): L30. arXiv:2412.05535. Bibcode:2025ApJ...978L..30L. doi:10.3847/2041-8213/ad99d2.
