The 2MASS J04414489+2301513 Bab (abbreviated as 2M J044144) primary (a brown dwarf) has a large separation (12.4 arcseconds) companion, 2MASS J04414565+2301580 Aab (abbreviated as 2M J044145), which in turn has a nearby small separation substellar companion (separation of 0.23 arcseconds to the northeast). 2M J044145 has similar proper motion to 2M J044144 and is likely physically associated with the system.[8] The entire system of 4 objects is then a hierarchical quadruple of two binary objects orbiting each other.[8] The primary component Aa has a spectral type of M4.5 and a red apparent magnitude of 14.2.[3] Both components seem to be accreting mass from their stellar disks, as shown by their emission lines.[3] The four objects have a total mass of only 26% of the Sun, making it the quadruple star system with the lowest mass known.[3]
Planetary system
Artist's impression of the 2M 0441+23 system
The primary is orbited by a companion about 5–10 times the mass of Jupiter.[9] The mass of the primary brown dwarf is roughly 20 times the mass of Jupiter and its age is roughly one million years.[4] It is not clear whether this companion object is a sub-brown dwarf or a planet. The companion is very large with respect to its parent and must have formed within 1 million years or so. This seems to be too big and too fast to form like a regular planet from a disk around the central object.[4] It also fails the mass ratio criterion of the IAU definition of an exoplanet; the mass ratio with the primary is closer than 1/25.[10] It is still considered a planet by the NASA Exoplanet Archive and Extrasolar Planets Encyclopaedia though.[11][12]
^ abcdCutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
^Zacharias, N. (2012). "The fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". VizieR On-line Data Catalog. 1322. Bibcode:2012yCat.1322....0Z.
^ abTodorov, K. O.; Luhman, K. L.; Konopacky, Q. M.; McLeod, K. K.; Apai, D.; Ghez, A. M.; Pascucci, I.; Robberto, M. (2014). "A Search for Companions to Brown Dwarfs in the Taurus and Chamaeleon Star-Forming Regions". The Astrophysical Journal. 788 (1): 40. arXiv:1404.0213. Bibcode:2014ApJ...788...40T. doi:10.1088/0004-637X/788/1/40. S2CID16636388.
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