AB Aurigae

AB Aurigae is a Herbig Ae star[3] in the Auriga constellation. It is known for hosting a dust disk that may harbour a condensing planet or brown dwarf. The star could host a possible substellar companion in wide orbit. The star is part of the young Taurus-Auriga association, which is located in the Taurus Molecular Cloud.[9]

AB Aurigae

ALMA image of the dust ring (red) and gaseous spirals (blue) of the circumstellar disk AB Aurigae reveal gaseous spiral arms inside a wide dust gap, providing a hint of planet formation.
Credit: ALMA (ESO/NAOJ/NRAO)/Tang et al.
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 04h 55m 45.8445s
Declination +30° 33′ 04.292″
Apparent magnitude (V) 7.05[1]
Characteristics
Spectral type A0Vpe
U−B color index +0.04[2]
B−V color index +0.11[2]
Variable type INA (Herbig Ae)[3][4]
Astrometry
Radial velocity (Rv)8.90 ± 0.9[5] km/s
Proper motion (μ) RA: 3.926 ± 0.097[6] mas/yr
Dec.: -24.112 ± 0.068[6] mas/yr
Parallax (π)6.1400 ± 0.0571[6] mas
Distance531 ± 5 ly
(163 ± 2 pc)
Details
Mass2.4[7] M☉
Radius2.5[8] R☉
Luminosity47[7] L☉
Temperature9772[7] K
Other designations
BD+30° 741, HD 31293, HIP 22910, SAO 57506
Database references
SIMBADdata

Protoplanetary disk

In 2017 scientists used the Atacama Large Millimeter/submillimeter Array to take an image of the protoplanetary disk around AB Aurigae. The image showed a dusty disk which has a radius of about 120 astronomical units and a distinct "gap". Inside this gap gaseous spiral arms are detected in CO.[10][3]

Planetary system

Oppenheimer et al. (2008)[11] observed an annulus feature in AB Aurigae's dust disk between 43 and 302 AU from the star, a region never seen before. An azimuthal gap in an annulus of dust at a radius of 102 AU would suggest the formation of at least one small body at an orbital distance of nearly 100 AU. Such object could turn out either a massive planetary companion or more likely a brown dwarf companion, in both cases located at nearly 100 AU from the bright star. So far the object is unconfirmed.

Observations with ALMA found two gaseous spiral arms inside the disk. These are best explained by an unseen planet with a semimajor axis of about 60-80 au. An additional planet with a semimajor axis of 30 au and with a large pitch angle compared to the disk (likely higher inclination) could explain the emptiness of the inner dusty disk.[3]

The AB Aurigae planetary system[11]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(years)		 Eccentricity Inclination Radius
b (unconfirmed) ≥5–37 MJ 102 ≥800 ? — —
  • AB Aurigae and its dust disk seen by Hubble


References
  1. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  2. Nicolet, B. (1964). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics Supplement Series. 34: 1–49. Bibcode:1978A&AS...34....1N.
  3. Tang, Ya-Wen; Guilloteau, Stephane; Dutrey, Anne; Muto, Takayuki; Shen, Bo-Ting; Gu, Pin-Gao; Inutsuka, Shu-ichiro; Momose, Munetake; Pietu, Vincent; Fukagawa, Misato; Chapillon, Edwige (May 2017). "Planet Formation in AB Aurigae: Imaging of the Inner Gaseous Spirals Observed inside the Dust Cavity". The Astrophysical Journal. 840 (1): 32. arXiv:1704.02699. Bibcode:2017ApJ...840...32T. doi:10.3847/1538-4357/aa6af7. ISSN 0004-637X. S2CID 119351517.
  4. Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". ARep. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 125853869.
  5. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  6. Gaia Collaboration (2018-08-01). "Gaia Data Release 2 - Summary of the contents and survey properties". Astronomy & Astrophysics. 616: A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. ISSN 0004-6361. S2CID 49211658.
  7. Tannirkulam, A.; Monnier, J. D.; Harries, T. J.; Millan‐Gabet, R.; Zhu, Z.; Pedretti, E.; Ireland, M.; Tuthill, P.; Ten Brummelaar, T.; McAlister, H.; Farrington, C.; Goldfinger, P. J.; Sturmann, J.; Sturmann, L.; Turner, N. (2008). "A Tale of Two Herbig Ae Stars, MWC 275 and AB Aurigae: Comprehensive Models for Spectral Energy Distribution and Interferometry". The Astrophysical Journal. 689 (1): 513–531. arXiv:0808.1728. Bibcode:2008ApJ...689..513T. doi:10.1086/592346. S2CID 45548.
  8. Li, Dan; Pantin, Eric; Telesco, Charles M.; Zhang, Han; Wright, Christopher M.; Barnes, Peter J.; Packham, Chris; Mariñas, Naibí (2016). "AN ORDERED MAGNETIC FIELD IN THE PROTOPLANETARY DISK OF AB Aur REVEALED BY MID-INFRARED POLARIMETRY". The Astrophysical Journal. 832 (1): 18. arXiv:1609.02493. Bibcode:2016ApJ...832...18L. doi:10.3847/0004-637X/832/1/18. S2CID 118475064.
  9. Gagné, Jonathan; Mamajek, Eric E.; Malo, Lison; Riedel, Adric; Rodriguez, David; Lafrenière, David; Faherty, Jacqueline K.; Roy-Loubier, Olivier; Pueyo, Laurent; Robin, Annie C.; Doyon, René (March 2018). "BANYAN. XI. The BANYAN Σ Multivariate Bayesian Algorithm to Identify Members of Young Associations with 150 pc". Astrophysical Journal. 856 (1): 23. arXiv:1801.09051. Bibcode:2018ApJ...856...23G. doi:10.3847/1538-4357/aaae09. ISSN 0004-637X. S2CID 119185386.
  10. "Astronomers Found Spirals Inside a Dust Gap of a Young Star Forming Disk". ALMA. Retrieved 2020-02-22.
  11. Oppenheimer, Ben R.; et al. (2008). "The Solar-System-Scale Disk around AB Aurigae". The Astrophysical Journal. 679 (2): 1574–1581. arXiv:0803.3629. Bibcode:2008ApJ...679.1574O. doi:10.1086/587778. S2CID 17424945.

Further reading


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