Delorme 1
b_HST_WFC3.jpg) The binary Delorme 1 (AB) is in the center and the companion is the source on the upper right. Credit: NASA/ESA Hubble WFC3; Daniel Apai et al. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Phoenix |
| Right ascension | 01h 03m 35.6551s |
| Declination | −55° 15′ 56.243″ |
| Apparent magnitude (V) | 15.40 ±0.05 |
| Characteristics | |
| Evolutionary stage | red dwarf |
| Spectral type | M5/6+M5/6+L0(VLG)[1] |
| Variable type | flare star[1] |
| Astrometry | |
| Radial velocity (Rv) | 5.2 ±1.6[2] km/s |
| Proper motion (μ) | RA: 111.6 ±3.6 mas/yr[2] Dec.: -43.8 ±8.1 mas/yr[2] |
| Parallax (π) | 21.18 ± 1.37 mas[3] |
| Distance | 154 ± 10 ly (47 ± 3 pc) |
| Details[4] | |
| Delorme 1A | |
| Mass | 0.19 ±0.02 M☉ |
| Delorme 1B | |
| Mass | 0.17 ±0.02 M☉ |
| Position (relative to Delorme 1A)[4] | |
| Component | Delorme 1B |
| Epoch of observation | 2012 |
| Angular distance | 0.249 ±0.003″ |
| Projected separation | 12 AU |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Delorme 1 (2MASS J01033563-5515561) is a binary star with a planetary-mass companion (PMC) or protoplanet in a circumbinary orbit.[4] The PMC is notable for showing signs of accretion, despite being 30-45 Myr old, making it similar to Peter Pan disks.[1][5][6] These disks show characteristics of a gas-rich disk at unexpected high ages.[7]
The binary system
[edit]The star was resolved in 2013 with the Very Large Telescope NACO instrument by Delorme et al. A spectrum of the binary was taken with GMOS at Gemini South, which showed a spectral type of M5.5/M6 and strong Hydrogen-alpha emission. The astrometry showed that this star belongs to the Tucana-Horologium association. The binary is separated by around 12 astronomical units (AU).[4] In 2014 Riedel et al. found a better match with the Carina association, which has a similar age as Tuc-Hor. They also found the system to be over-luminous, which might either hint at a younger age or further multiplicity.[3] Other searches do, however, find a better match with Tuc-Hor.[2] Because the Washington Double Star Catalog named the binary ** DLR 1 after the first author of the discovery paper in 2013, Eriksson et al. suggested the name Delorme 1 for the binary.[1] The binary is named after Philippe Delorme.[8]
The circumstellar companion
[edit]The binary companion was discovered in 2013 as an object with a mass between 12 and 14 MJ and a separation of 84 AU from the central binary. It had a spectrum similar to early L-dwarfs, but redder than field L-dwarfs.[4] In 2020 Eriksson et al. discovered Hydrogen-alpha, -beta and Helium I lines from Delorme 1 (AB)b using MUSE. This is seen as a clear sign of accretion on a planetary-mass object. The spectral type of this object was determined to be L0 with very low gravity due to stronger than expected vanadium oxide absorption.[1] H-alpha can be influenced by chromospheric activity, complicating its interpretation. Betti et al. discovered Paschen and Brackett lines in Delorme 1 (AB)b in the near-infrared, using TripleSpec at SOAR. These observations are in agreement with planetary-shock accretion.[5] In 2023 Ringqvist et al. observed Delorme 1 (AB)b with the VLT UVES, detecting neutral hydrogen in the ultraviolet.[6] Both near-infrared and ultraviolet observations show an accretion rate of about (about 1.2 to 2.3 the mass of 10 Hygiea per year).[5][6] The circumplanetary disk that fuels this accretion around Delorme 1 (AB)b is not detected (as of August 2024).[6] The planet and the star were observed with MIRI/IFU in August 2023, which should reveal any disk around the planet or star in a future work.[9]
Delorme 1 (AB)b has been called a protoplanet candidate and a super-Jupiter.[5][6] The researchers found that the high accretion is in better agreement with a formation via disk fragmentation, hinting that it might have formed from a circumstellar disk.[5] Giant planets and brown dwarfs are thought to form via disk fragmentation in rare cases in the outer regions of a disk (r>50 AU).[10] Teasdale et al. modelled three formation scenarios in which the planet could have formed. In the first two scenarios the planet forms in a massive disk via gravitational instability. The first two scenarios produce planets that have accretion and separation comparable to the observed ones, but the resulting planets are more massive than Delorme 1 (AB)b. In a third scenario the planet forms via core accretion in a less massive disk much closer to the binary. In this third scenario the mass and accretion are similar to the observed ones, but the separation is smaller.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 12 to 14 MJ | 102+47 −27 |
1682+1308 −628 |
0.32+0.27 −0.23 |
127+17 −8° |
1.5764[5] RJ |
References
[edit]- ^ a b c d e Eriksson, Simon C.; Asensio Torres, Rubén; Janson, Markus; Aoyama, Yuhiko; Marleau, Gabriel-Dominique; Bonnefoy, Mickael; Petrus, Simon (2020-06-01). "Strong Halpha emission and signs of accretion in a circumbinary planetary mass companion from MUSE". Astronomy and Astrophysics. 638: L6. arXiv:2005.11725. Bibcode:2020A&A...638L...6E. doi:10.1051/0004-6361/202038131. ISSN 0004-6361. S2CID 218870278.
- ^ a b c Gagné, Jonathan; Lafrenière, David; Doyon, René; Malo, Lison; Artigau, Étienne (2015-01-01). "BANYAN. V. A Systematic All-sky Survey for New Very Late-type Low-mass Stars and Brown Dwarfs in Nearby Young Moving Groups". The Astrophysical Journal. 798 (2): 73. arXiv:1410.4864. Bibcode:2015ApJ...798...73G. doi:10.1088/0004-637X/798/2/73. ISSN 0004-637X.
- ^ a b Riedel, Adric R.; Finch, Charlie T.; Henry, Todd J.; Subasavage, John P.; Jao, Wei-Chun; Malo, Lison; Rodriguez, David R.; White, Russel J.; Gies, Douglas R.; Dieterich, Sergio B.; Winters, Jennifer G.; Davison, Cassy L.; Nelan, Edmund P.; Blunt, Sarah C.; Cruz, Kelle L. (2014-04-01). "The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9 m Program: Trigonometric Parallaxes of Nearby Low-mass Active and Young Systems". The Astronomical Journal. 147 (4): 85. arXiv:1401.0722. Bibcode:2014AJ....147...85R. doi:10.1088/0004-6256/147/4/85. ISSN 0004-6256.
- ^ a b c d e f Delorme, P.; Gagné, J.; Girard, J. H.; Lagrange, A. M.; Chauvin, G.; Naud, M. -E.; Lafrenière, D.; Doyon, R.; Riedel, A.; Bonnefoy, M.; Malo, L. (2013-05-01). "Direct-imaging discovery of a 12-14 Jupiter-mass object orbiting a young binary system of very low-mass stars". Astronomy and Astrophysics. 553: L5. arXiv:1303.4525. Bibcode:2013A&A...553L...5D. doi:10.1051/0004-6361/201321169. ISSN 0004-6361.
- ^ a b c d e f Betti, S. K.; Follette, K. B.; Ward-Duong, K.; Aoyama, Y.; Marleau, G. -D.; Bary, J.; Robinson, C.; Janson, M.; Balmer, W.; Chauvin, G.; Palma-Bifani, P. (2022-08-01). "Near-infrared Accretion Signatures from the Circumbinary Planetary-mass Companion Delorme 1 (AB)b". The Astrophysical Journal. 935 (1): L18. arXiv:2208.05016. Bibcode:2022ApJ...935L..18B. doi:10.3847/2041-8213/ac85ef. ISSN 0004-637X.
- ^ a b c d e Ringqvist, Simon C.; Viswanath, Gayathri; Aoyama, Yuhiko; Janson, Markus; Marleau, Gabriel-Dominique; Brandeker, Alexis (2023-01-01). "Resolved near-UV hydrogen emission lines at 40-Myr super-Jovian protoplanet Delorme 1 (AB)b. Indications of magnetospheric accretion". Astronomy and Astrophysics. 669: L12. arXiv:2212.03207. Bibcode:2023A&A...669L..12R. doi:10.1051/0004-6361/202245424. ISSN 0004-6361.
- ^ Silverberg, Steven M.; Wisniewski, John P.; Kuchner, Marc J.; Lawson, Kellen D.; Bans, Alissa S.; Debes, John H.; Biggs, Joseph R.; Bosch, Milton K. D.; Doll, Katharina; Luca, Hugo A. Durantini; Enachioaie, Alexandru; Hamilton, Joshua; Holden, Jonathan; Hyogo, Michiharu; the Disk Detective Collaboration (2020-01-14). "Peter Pan Disks: Long-lived Accretion Disks Around Young M Stars". The Astrophysical Journal. 890 (2): 106. arXiv:2001.05030. Bibcode:2020ApJ...890..106S. doi:10.3847/1538-4357/ab68e6. S2CID 210718358.
- ^ "Members of the Exoplanets team". IPAG - Institut de Planétologie et d’Astrophysique de Grenoble. Retrieved 2024-08-27.
- ^ Perrin, Marshall; Balmer, William; Chen, Christine; Girard, Julien; Hoch, Kielan K. W.; Kammerer, Jens; Konopacky, Quinn; Lu, Cicero; Mountain, Matt; Pueyo, Laurent; Rebollido, Isabel; Rickman, Emily; Ruffio, Jean-Baptiste; Ward-Duong, Kimberly; Worthen, Kadin (2022-09-01). "Imaging Spectroscopy of the Coldest Imaged Exoplanet and a Low-Mass Accreting Protoplanet". JWST Proposal. Cycle 2: 2778. Bibcode:2022jwst.prop.2778P.
- ^ Rice, Ken; Lopez, Eric; Forgan, Duncan; Biller, Beth (2015-12-01). "Disc fragmentation rarely forms planetary-mass objects". Monthly Notices of the Royal Astronomical Society. 454 (2): 1940–1947. arXiv:1508.06528. Bibcode:2015MNRAS.454.1940R. doi:10.1093/mnras/stv1997. ISSN 0035-8711.
- ^ Teasdale, Matthew; Stamatellos, Dimitris (2024-08-01). "On the potential origin of the circumbinary planet Delorme 1 (AB)b". Monthly Notices of the Royal Astronomical Society. 533 (2): 2294–2302. arXiv:2408.06231. Bibcode:2024MNRAS.533.2294T. doi:10.1093/mnras/stae1964. ISSN 0035-8711.
- ^ Blunt, Sarah; Nielsen, Eric L.; De Rosa, Robert J.; Konopacky, Quinn M.; Ryan, Dominic; Wang, Jason J.; Pueyo, Laurent; Rameau, Julien; Marois, Christian; Marchis, Franck; Macintosh, Bruce; Graham, James R.; Duchêne, Gaspard; Schneider, Adam C. (2017-05-01). "Orbits for the Impatient: A Bayesian Rejection-sampling Method for Quickly Fitting the Orbits of Long-period Exoplanets". The Astronomical Journal. 153 (5): 229. arXiv:1703.10653. Bibcode:2017AJ....153..229B. doi:10.3847/1538-3881/aa6930. ISSN 0004-6256.
68 % confidence range