Langbahn Team – Weltmeisterschaft

KPNO-Tau 12

KPNO-Tau 12

KPNO-Tau 12 (red object in the center)
Credit: PanSTARRS & Meli_thev
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 04h 19m 01.28s
Declination +28° 02′ 48.14″
Apparent magnitude (V) 23.228 ±0.023[1]
Characteristics
Evolutionary stage low-mass brown dwarf or planetary-mass object
Spectral type M9.25±0.5[2]
Astrometry
Proper motion (μ) RA: 7.09 ±5.60 mas/yr[3]
Dec.: -28.41 ±5.27 mas/yr[3]
Distance145 ±15 pc[3]
Details
Mass12.7+1.6
−1.8[4] MJup
Radius2.22+0.11
−0.17[4] RJup
Luminosity (bolometric)10-2.99 ±0.16[3] L☉
Temperature2170 ±200 K[3] K
Rotational velocity (v sin i)5.0[5] km/s
Age1-10[3] Myr
Other designations
[BLH2002] KPNO-Tau 12, 2MASS J04190126+2802487, SSTtau 041901.2+280248, TIC 58285609, UGCS J041901.27+280248.3, WISE J041901.26+280248.2, Gaia DR2 164487734085116800
Database references
SIMBADdata

KPNO-Tau 12 (also called 2MASS J0419012+280248) is a low-mass brown dwarf or free-floating planetary-mass object that is surrounded by a disk. The planetary-mass object is actively accreting material from the disk.[6]

Discovery

KPNO-Tau 12 was identified in 2003 in data from a survey of the Taurus Molecular Clouds taken with a telescope at the Kitt Peak National Observatory (KPNO) and 2MASS. The object was observed with the MMT Observatory/Blue Channel spectrometer and with Keck/LRIS. KPNO-Tau 12 showed a spectral type of M9 and also showed strong Hydrogen-alpha emission. At the time its mass was estimated to be around 0.02 M☉ (or 21 MJ), which would make it a brown dwarf.[6] Since then several works found that it likely has a mass near or below the deuterium-burning limit, which makes this object a low-mass brown dwarf or planetary-mass object (e.g. 14.6 MJ,[1] 13.6 MJ[7], 6-7 MJ[2], 16.5 MJ[8], 17.8+6.7
−4.6 MJ[9], 12.7+1.6
−1.8 MJ[4]).

Atmosphere

Observations with Keck/LRIS showed several absorption features. These are titanium oxide, calcium hydride, vanadium oxide, sodium and potassium.[6] A spectrum with Keck/NIRSPEC was interpreted to be consistent with very low gravity. This is typical for young sources.[10] Several re-classifications of the spectral type were made over the years. In 2013 it was re-classified as a M9.25±0.5.[2] In 2018 it was re-classified as a L0.7±1.1, which could make this object an early L-dwarf.[3] A spectrum observed with VLT/SINFONI was published in 2022, estimating a spectral type of M9.8.[11]

Protoplanetary disk

KPNO-Tau 12 showed strongest H-alpha emission in both the MMT and Keck optical spectra. It also showed helium (He I) and calcium (Ca II IR triplet) emission in the Keck spectrum, which are usually seen in stars that undergo intense accretion of material from a surrounding protoplanetary disk.[6] Additionally a Keck infrared spectrum shows a prominent emission line (see figure 10 of their work), which is described as Paschen β at 1.28 μm in the appendix of the paper.[10] Paschen lines can be used as additional accretion indicators.[12] In 2010 two works used observations with the Spitzer Space Telescope. These two works first identified infrared excess around KPNO-Tau 12 and classified it as a class II disk. A class II disk is composed of both a gaseous and a dusty part and belongs to the protoplanetary disks.[13][14] Observation with the Spitzer Infrared Spectrograph showed that the silicate emission feature is likely missing.[15] The dust mass of the disk was measured to be 1.223 ME[8] or 0.6–1.1 ME,[16] depending on the work. The total (gas+dust) mass was measured to be 0.66 MJ[9] or 0.095 MJ,[17] depending on the work. The dust temperature was estimated to be 7.0–13.8 Kelvin and the dust grains are smaller than 27.5 millimeters.[16]

The KPNO-Tau 12 planetary system[16]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(years) 		Eccentricity Inclination Radius
protoplanetary disk 0.003–(6.4–95.5) AU 25.50–26.30° —

Other planetary-mass objects in Taurus

A few other free-floating planetary-mass objects are known in the Taurus Clouds.[18][19] These include three other objects with possible disks around them.[19]

See also

Other free-floating planetary-mass objects with disks:

Other planetary-mass objects with disks that bound to a star:

References

  1. ^ a b Kraus, Adam L.; White, Russel J.; Hillenbrand, Lynne A. (September 2006). "Multiplicity and Optical Excess across the Substellar Boundary in Taurus". The Astrophysical Journal. 649 (1): 306–318. arXiv:astro-ph/0602449. Bibcode:2006ApJ...649..306K. doi:10.1086/503665. ISSN 0004-637X.
  2. ^ a b c Canty, J. I.; Lucas, P. W.; Roche, P. F.; Pinfield, D. J. (November 2013). "Towards precise ages and masses of Free Floating Planetary Mass Brown Dwarfs". Monthly Notices of the Royal Astronomical Society. 435 (3): 2650–2664. arXiv:1308.1296. Bibcode:2013MNRAS.435.2650C. doi:10.1093/mnras/stt1477. ISSN 0035-8711.
  3. ^ a b c d e f Zhang, Zhoujian; Liu, Michael C.; Best, William M. J.; Magnier, Eugene A.; Aller, Kimberly M.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Metcalfe, N.; Wainscoat, R. J.; Waters, C. (May 2018). "The Pan-STARRS1 Proper-motion Survey for Young Brown Dwarfs in Nearby Star-forming Regions. I. Taurus Discoveries and a Reddening-free Classification Method for Ultracool Dwarfs". The Astrophysical Journal. 858 (1): 41. arXiv:1804.01533. Bibcode:2018ApJ...858...41Z. doi:10.3847/1538-4357/aab269. ISSN 0004-637X.
  4. ^ a b c Bryan, Marta L.; Ginzburg, Sivan; Chiang, Eugene; Morley, Caroline; Bowler, Brendan P.; Xuan, Jerry W.; Knutson, Heather A. (December 2020). "As the Worlds Turn: Constraining Spin Evolution in the Planetary-mass Regime". The Astrophysical Journal. 905 (1): 37. arXiv:2010.07315. Bibcode:2020ApJ...905...37B. doi:10.3847/1538-4357/abc0ef. ISSN 0004-637X.
  5. ^ Mohanty, Subhanjoy; Jayawardhana, Ray; Basri, Gibor (June 2005). "The T Tauri Phase Down to Nearly Planetary Masses: Echelle Spectra of 82 Very Low Mass Stars and Brown Dwarfs". The Astrophysical Journal. 626 (1): 498–522. arXiv:astro-ph/0502155. Bibcode:2005ApJ...626..498M. doi:10.1086/429794. ISSN 0004-637X.
  6. ^ a b c d Luhman, K. L.; Briceño, César; Stauffer, John R.; Hartmann, Lee; Barrado y Navascués, D.; Caldwell, Nelson (July 2003). "New Low-Mass Members of the Taurus Star-forming Region". The Astrophysical Journal. 590 (1): 348–356. arXiv:astro-ph/0304414. Bibcode:2003ApJ...590..348L. doi:10.1086/374983. ISSN 0004-637X.
  7. ^ Kirk, Helen; Myers, Philip C. (February 2011). "Young Stellar Groups and Their Most Massive Stars". The Astrophysical Journal. 727 (2): 64. arXiv:1011.1416. Bibcode:2011ApJ...727...64K. doi:10.1088/0004-637X/727/2/64. ISSN 0004-637X.
  8. ^ a b Pascucci, I.; Testi, L.; Herczeg, G. J.; Long, F.; Manara, C. F.; Hendler, N.; Mulders, G. D.; Krijt, S.; Ciesla, F.; Henning, Th; Mohanty, S.; Drabek-Maunder, E.; Apai, D.; Szűcs, L.; Sacco, G. (November 2016). "A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation". The Astrophysical Journal. 831 (2): 125. arXiv:1608.03621. Bibcode:2016ApJ...831..125P. doi:10.3847/0004-637X/831/2/125. ISSN 0004-637X.
  9. ^ a b Akeson, Rachel L.; Jensen, Eric L. N.; Carpenter, John; Ricci, Luca; Laos, Emily; Nogueira, Natasha F.; Suen-Lewis, Emma M. (February 2019). "Resolved Young Binary Systems and Their Disks". The Astrophysical Journal. 872 (2): 158. arXiv:1901.05029. Bibcode:2019ApJ...872..158A. doi:10.3847/1538-4357/aaff6a. ISSN 0004-637X.
  10. ^ a b Martin, Emily C.; Mace, Gregory N.; McLean, Ian S.; Logsdon, Sarah E.; Rice, Emily L.; Kirkpatrick, J. Davy; Burgasser, Adam J.; McGovern, Mark R.; Prato, Lisa (March 2017). "Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey". The Astrophysical Journal. 838 (1): 73. arXiv:1703.03811. Bibcode:2017ApJ...838...73M. doi:10.3847/1538-4357/aa6338. ISSN 0004-637X.
  11. ^ Almendros-Abad, V.; Mužić, K.; Moitinho, A.; Krone-Martins, A.; Kubiak, K. (2022-01-01). "Youth analysis of near-infrared spectra of young low-mass stars and brown dwarfs". Astronomy & Astrophysics. 657: A129. arXiv:2110.06368. Bibcode:2022A&A...657A.129A. doi:10.1051/0004-6361/202142050. ISSN 0004-6361.
  12. ^ 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. (August 2022). "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.
  13. ^ Luhman, K. L.; Allen, P. R.; Espaillat, C.; Hartmann, L.; Calvet, N. (January 2010). "The Disk Population of the Taurus Star-Forming Region". The Astrophysical Journal Supplement Series. 186 (1): 111–174. arXiv:0911.5457. Bibcode:2010ApJS..186..111L. doi:10.1088/0067-0049/186/1/111. ISSN 0067-0049.
  14. ^ Rebull, L. M.; Padgett, D. L.; McCabe, C.-E.; Hillenbrand, L. A.; Stapelfeldt, K. R.; Noriega-Crespo, A.; Carey, S. J.; Brooke, T.; Huard, T.; Terebey, S.; Audard, M.; Monin, J.-L.; Fukagawa, M.; Güdel, M.; Knapp, G. R. (February 2010). "The Taurus Spitzer Survey: New Candidate Taurus Members Selected Using Sensitive Mid-Infrared Photometry". The Astrophysical Journal Supplement Series. 186 (2): 259–307. arXiv:0911.3176. Bibcode:2010ApJS..186..259R. doi:10.1088/0067-0049/186/2/259. ISSN 0067-0049.
  15. ^ Furlan, E.; Luhman, K. L.; Espaillat, C.; D'Alessio, P.; Adame, L.; Manoj, P.; Kim, K. H.; Watson, Dan M.; Forrest, W. J.; McClure, M. K.; Calvet, N.; Sargent, B. A.; Green, J. D.; Fischer, W. J. (July 2011). "The Spitzer Infrared Spectrograph Survey of T Tauri Stars in Taurus". The Astrophysical Journal Supplement Series. 195 (1): 3. Bibcode:2011ApJS..195....3F. doi:10.1088/0067-0049/195/1/3. ISSN 0067-0049.
  16. ^ a b c Ballering, Nicholas P.; Eisner, Josh A. (April 2019). "Protoplanetary Disk Masses from Radiative Transfer Modeling: A Case Study in Taurus". The Astronomical Journal. 157 (4): 144. arXiv:1903.08283. Bibcode:2019AJ....157..144B. doi:10.3847/1538-3881/ab0a56. ISSN 0004-6256.
  17. ^ Rilinger, Anneliese M.; Espaillat, Catherine C. (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.
  18. ^ Quanz, Sascha P.; Goldman, Bertrand; Henning, Thomas; Brandner, Wolfgang; Burrows, Adam; Hofstetter, Lorne W. (January 2010). "Search for Very Low-Mass Brown Dwarfs and Free-Floating Planetary-Mass Objects in Taurus". The Astrophysical Journal. 708 (1): 770–784. arXiv:0911.1925. Bibcode:2010ApJ...708..770Q. doi:10.1088/0004-637X/708/1/770. ISSN 0004-637X.
  19. ^ a b 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. (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.
Quelle: http://en.wikipedia.org/wiki/KPNO-Tau_12