binaries: spectroscopic; binaries: visual; brown dwarfs; stars: individual: WISE J072003.20-084651.2; stars: low-mass; stars: magnetic field
Abstract :
[en] We report observations of the recently discovered, nearby late-M dwarf WISE J072003.20-084651.2. New astrometric measurements obtained with the TRAPPIST telescope improve the distance measurement to 6.0 ± 1.0 pc and confirm the low tangential velocity (3.5 ± 0.6 km s[SUP]-1[/SUP]) reported by Scholz. Low-resolution optical spectroscopy indicates a spectral type of M9.5 and prominent Hα emission (< {{log }[SUB]10[/SUB]}{{L}[SUB]Hα [/SUB]}/{{L}[SUB]bol[/SUB]}> = -4.68 ± 0.06), but no evidence of subsolar metallicity or Li i absorption. Near-infrared spectroscopy reveals subtle peculiarities that can be explained by the presence of a T5 binary companion, and high-resolution laser guide star adaptive optics imaging reveals a faint (ΔH = 4.1) candidate source 0\buildrel{\prime\prime}\over{.} 14 (0.8 AU) from the primary. With high-resolution optical and near-infrared spectroscopy, we measure a stable radial velocity of +83.8 ± 0.3 km s[SUP]-1[/SUP], indicative of old disk kinematics and consistent with the angular separation of the possible companion. We measure a projected rotational velocity of v sin i = 8.0 ± 0.5 km s[SUP]-1[/SUP] and find evidence of low-level variabilty (˜1.5%) in a 13 day TRAPPIST light curve, but cannot robustly constrain the rotational period. We also observe episodic changes in brightness (1%-2%) and occasional flare bursts (4%-8%) with a 0.8% duty cycle, and order-of-magnitude variations in Hα line strength. Combined, these observations reveal WISE J0720-0846 to be an old, very low-mass binary whose components straddle the hydrogen burning minimum mass, and whose primary is a relatively rapid rotator and magnetically active. It is one of only two known binaries among late M dwarfs within 10 pc of the Sun, both of which harbor a mid T-type brown dwarf companion. We show that while this specific configuration is rare (≲1.6% probability), roughly 25% of binary companions to late-type M dwarfs in the local population are likely low-temperature T or Y brown dwarfs. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Burgasser, Adam J.; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA, 92093, USA ; Instituto de Astrofísica de Canarias (IAC), La Laguna, Tenerife, Spain
Gillon, Michaël ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Melis, Carl; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA, 92093, USA
Bowler, Brendan P.; California Institute of Technology, Division of Geological and Planetary Sciences, 1200 East California Boulevard, Pasadena, CA 91101, USA
Michelsen, Eric L.; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA, 92093, USA
Bardalez Gagliuffi, Daniella; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA, 92093, USA
Gelino, Christopher R.; NASA Exoplanet Science Institute, Mail Code 100-22, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125, USA ; Infrared Processing and Analysis Center, MC 100-22, California Institute of Technology, Pasadena, CA 91125, USA
Jehin, Emmanuel ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Delrez, Laetitia ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Manfroid, Jean ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)
Blake, Cullen H.; Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA)
Language :
English
Title :
WISE J072003.20-084651.2: an Old and Active M9.5 + T5 Spectral Binary 6 pc from the Sun
Allard F.; Homeier D. and Freytag B. 2012 in ASP Conf. Ser. 448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun 91 ed C. M. Johns-Krull, M. K. Browning and A. A. West (San Francisco, CA: ASP)
Allen P. R. 2007 ApJ 668 492
Allen P. R.; Koerner D. W.; Reid I. N. and Trilling D. E. 2005 ApJ 625 385
Artigau É, Radigan J.; Folkes S. et al 2010 ApJL 718 L38
Bailer-Jones C. A. L. and Lamm M. 2003 MNRAS 339 477
Bardalez Gagliuffi D. C.; Burgasser A. J.; Gelino C. R. et al 2014 ApJ 794 143
Basri G. and Reiners A. 2006 AJ 132 663
Bihain G.; Scholz R.-D.; Storm J. and Schnurr O. 2013 A&A 557 A43
Bildsten L.; Brown E. F.; Matzner C. D. and Ushomirsky G. 1997 ApJ 482 442
Biller B. A.; Kasper M.; Close L. M.; Brandner W. and Kellner S. 2006 ApJL 641 L141
Blake C. H.; Charbonneau D. and White R. J. 2010 ApJ 723 684
Blake C. H.; Charbonneau D.; White R. J. et al 2008 ApJL 678 L125
Bochanski J. J.; West A. A.; Hawley S. L. and Covey K. R. 2007 AJ 133 531
Bouy H.; Brandner W.; Martín E. L. et al 2003 AJ 126 1526
Boyd M. R.; Henry T. J.; Jao W.-C.; Subasavage J. P. and Hambly N. C. 2011 AJ 142 92
Burgasser A. J. 2004 ApJS 155 191
Burgasser A. J. 2007 ApJ 659 655
Burgasser A. J. 2007 AJ 134 1330
Burgasser A. J. 2014 in Proc. ASI Conf. Ser. 11, 2013 Int. Workshop on Spectral Stellar Libraries 7 ed H. P. Singh, P. Prugniel and I. Vauglin
Burgasser A. J.; Cruz K. L.; Cushing M. et al 2010 ApJ 710 1142
Burgasser A. J.; Kirkpatrick J. D.; Cruz K. L. et al 2006 ApJS 166 585
Burgasser A. J.; Kirkpatrick J. D.; Reid I. N. et al 2003 ApJ 586 512
Burgasser A. J.; Liu M. C.; Ireland M. J.; Cruz K. L. and Dupuy T. J. 2008 ApJ 681 579
Burgasser A. J.; Luk C.; Dhital S. et al 2012 ApJ 757 110
Burgasser A. J.; Marley M. S.; Ackerman A. S. et al 2002 ApJL 571 L151
Burgasser A. J. and McElwain M. W. 2006 AJ 131 1007
Burgasser A. J.; McElwain M. W.; Kirkpatrick J. D. et al 2004 AJ 127 2856
Burgasser A. J.; Sheppard S. S. and Luhman K. L. 2013 ApJ 772 129
Burgasser A. J.; Sitarski B. N.; Gelino C. R.; Logsdon S. E. and Perrin M. D. 2011 ApJ 739 49
Burgasser A. J.; Witte S.; Helling C. et al 2009 ApJ 697 148
Burningham B.; Cardoso C. V.; Smith L. et al 2013 MNRAS 433 457
Burrows A.; Hubbard W. B.; Lunine J. I. and Liebert J. 2001 RvMP 73 719
Churchill C. W. 1995 Lick Technical Report 74
Close L. M.; Siegler N.; Freed M. and Biller B. 2003 ApJ 587 407
Costa E.; Méndez R. A.; Jao W.-C. et al 2005 AJ 130 337
Cruz K. L.; Burgasser A. J.; Reid I. N. and Liebert J. 2004 ApJL 604 L61
Cruz K. L.; Kirkpatrick J. D. and Burgasser A. J. 2009 AJ 137 3345
Cruz K. L.; Reid I. N.; Kirkpatrick J. D. et al 2007 AJ 133 439
Cushing M. C.; Kirkpatrick J. D.; Gelino C. R. et al 2011 ApJ 743 50
Cushing M. C.; Vacca W. D. and Rayner J. T. 2004 PASP 116 362
Davies S. R. 1990 MNRAS 244 93
Day-Jones A. C.; Marocco F.; Pinfield D. J. et al 2013 MNRAS 430 1171
Deacon N. R.; Hambly N. C. and Cooke J. A. 2005 A&A 435 363
Deacon N. R.; Hambly N. C.; Henry T. J. et al 2005 AJ 129 409
Deacon N. R.; Liu M. C.; Magnier E. A. et al 2014 ApJ 792 119
Dieterich S. B.; Henry T. J.; Golimowski D. A.; Krist J. E. and Tanner A. M. 2012 AJ 144 64
Dieterich S. B.; Henry T. J.; Jao W.-C. et al 2014 AJ 147 94
Dupuy T. J. and Liu M. C. 2011 ApJ 733 122
Dupuy T. J. and Liu M. C. 2012 ApJS 201 19
Eggen O. J. 1969 PASP 81 553
Faherty J. K.; Burgasser A. J.; Walter F. M. et al 2012 ApJ 752 56
Ford E. B. 2005 AJ 129 1706
Gelino C. R. and Burgasser A. J. 2010 AJ 140 110
Gillon M.; Triaud A. H. M. J.; Jehin E. et al 2013 A&A 555 L5
Gizis J. E.; Monet D. G.; Reid I. N. et al 2000 AJ 120 1085
Hambaryan V.; Staude A.; Schwope A. D. et al 2004 A&A 415 265
Hambly N. C.; Davenhall A. C.; Irwin M. J. and MacGillivray H. T. 2001 MNRAS 326 1315
Hambly N. C.; Henry T. J.; Subasavage J. P.; Brown M. A. and Jao W.-C. 2004 AJ 128 437
Hambly N. C.; Irwin M. J. and MacGillivray H. T. 2001 MNRAS 326 1295
Hambly N. C.; MacGillivray H. T.; Read M. A. et al 2001 MNRAS 326 1279
Hamuy M.; Walker A. R.; Suntzeff N. B. et al 1992 PASP 104 533
Harding L. K.; Hallinan G.; Konopacky Q. M. et al 2013 A&A 554 A113
Henry T. J.; Jao W.-C.; Subasavage J. P. et al 2006 AJ 132 2360
Henry T. J.; Subasavage J. P.; Brown M. A. et al 2004 AJ 128 2460
Hilton E. J.; West A. A.; Hawley S. L. and Kowalski A. F. 2010 AJ 140 1402
Innes R. T. A. 1907 Obs 30 310
Irwin J.; Berta Z. K.; Burke C. J. et al 2011 ApJ 727 56
Ivanov V. D.; Vaisanen P.; Kniazev A. Y. et al 2015 A&A in press, arXiv:1410.6792
Jehin E.; Gillon M.; Queloz D. et al 2011 Msngr 145 2
Kasper M.; Biller B. A.; Burrows A. et al 2007 A&A 471 655
Kirkpatrick J. D.; Cruz K. L.; Barman T. S. et al 2008 ApJ 689 1295
Kirkpatrick J. D.; Cushing M. C.; Gelino C. R. et al 2011 ApJS 197 19
Kirkpatrick J. D.; Gelino C. R.; Cushing M. C. et al 2012 ApJ 753 156
Kirkpatrick J. D.; Henry T. J. and Simons D. A. 1995 AJ 109 797
Kirkpatrick J. D.; Reid I. N.; Liebert J. et al 1999 ApJ 519 802
Kirkpatrick J. D.; Schneider A.; Fajardo-Acosta S. et al 2014 ApJ 783 122
Leggett S. K. 1992 ApJS 82 351
Lépine S. 2005 AJ 130 1680
Lépine S.; Rich R. M. and Shara M. M. 2003 AJ 125 1598
Lépine S.; Rich R. M. and Shara M. M. 2007 ApJ 669 1235
Liu M. C.; Dupuy T. J. and Leggett S. K. 2010 ApJ 722 311
Livingston W. and Wallace L. 1991 An atlas of the solar spectrum in the infrared from 1850 to 9000 cm-1 (1.1 to 5.4 micrometer)
Lomb N. R. 1976 Ap&SS 39 447
Looper D. L.; Gelino C. R.; Burgasser A. J. and Kirkpatrick J. D. 2008 ApJ 685 1183
Looper D. L.; Kirkpatrick J. D. and Burgasser A. J. 2007 AJ 134 1162
Lucas P. W.; Tinney C. G.; Burningham B. et al 2010 MNRAS 408 L56
Luhman K. L. 2013 ApJL 767 L1
Luhman K. L. 2014 ApJL 786 L18
Marley M. S.; Saumon D. and Goldblatt C. 2010 ApJL 723 L117
Martín E. L.; Delfosse X.; Basri G. et al 1999 AJ 118 2466
Martín E. L.; Guenther E.; Zapatero Osorio M. R.; Bouy H. and Wainscoat R. 2006 ApJL 644 L75
McLean I. S.; Graham J. R.; Becklin E. E. et al 2000 Proc. SPIE 4008 1048
McLean M.; Berger E. and Reiners A. 2012 ApJ 746 23
Mohanty S. and Basri G. 2003 ApJ 583 451
Nidever D. L.; Marcy G. W.; Butler R. P.; Fischer D. A. and Vogt S. S. 2002 ApJS 141 503
Pakhomov Y. V. and Zhao G. 2013 AJ 146 97
Parker Q. A.; Phillipps S.; Pierce M. J. et al 2005 MNRAS 362 689
Perryman M. A. C.; de Boer K. S.; Gilmore G. et al 2001 A&A 369 339
Phan-Bao N.; Bessell M. S.; Martín E. L. et al 2006 MNRAS 366 L40
Pravdo S. H.; Shaklan S. B.; Wiktorowicz S. J. et al 2006 ApJ 649 389
Press W. H. and Teukolsky S. A. 1988 ComPh 2 77
Probst R. G. and Liebert J. 1983 ApJ 274 245
Rayner J. T.; Toomey D. W.; Onaka P. M. et al 2003 PASP 115 362
Reid I. N.; Cruz K. L.; Allen P. et al 2004 AJ 128 463
Reid I. N.; Cruz K. L.; Kirkpatrick J. D. et al 2008 AJ 136 1290
Reid I. N.; Cruz K. L.; Laurie S. P. et al 2003 AJ 125 354
Reid I. N.; Gizis J. E. and Hawley S. L. 2002 AJ 124 2721
Reid I. N.; Hawley S. L. and Gizis J. E. 1995 AJ 110 1838
Reid I. N.; Kirkpatrick J. D.; Liebert J. et al 1999 ApJ 521 613
Reiners A. and Basri G. 2008 ApJ 684 1390
Reiners A. and Basri G. 2009 ApJ 705 1416
Roeser S.; Demleitner M. and Schilbach E. 2010 AJ 139 2440
Sahlmann J.; Lazorenko P. F.; Ségransan D. et al 2014 A&A 565 A20
Scargle J. D. 1982 ApJ 263 835
Schmidt S. J.; Cruz K. L.; Bongiorno B. J.; Liebert J. and Reid I. N. 2007 AJ 133 2258
Scholz R.-D. 2014 A&A 561 A113
Scholz R.-D.; Bihain G.; Schnurr O. and Storm J. 2011 A&A 532 L5
Scholz R.-D.; Lo Curto G.; Méndez R. A. et al 2005 A&A 439 1127
Schönrich R.; Binney J. and Dehnen W. 2010 MNRAS 403 1829
Schwarzenberg-Czerny A. 1997 ApJ 489 941
Shkolnik E. L.; Anglada-Escudé G.; Liu M. C. et al 2012 ApJ 758 56
Siegler N.; Close L. M.; Cruz K. L.; Martín E. L. and Reid I. N. 2005 ApJ 621 1023
Simons D. A. and Tokunaga A. 2002 PASP 114 169
Stellingwerf R. F. 1978 ApJ 224 953
Stephens D. C.; Leggett S. K.; Cushing M. C. et al 2009 ApJ 702 154
Stetson P. B. 1987 PASP 99 191
Teegarden B. J.; Pravdo S. H.; Hicks M. et al 2003 ApJL 589 L51
Tody D. 1986 Proc. SPIE 627 733
Tokunaga A. T.; Simons D. A. and Vacca W. D. 2002 PASP 114 180
Vacca W. D.; Cushing M. C. and Rayner J. T. 2003 PASP 115 389
van Dam M. A.; Bouchez A. H.; Le Mignant D. et al 2006 PASP 118 310
van den Bos W. H. 1927 BAN 3 261
Vogt S. S. 1987 PASP 99 1214
Walkowicz L. M.; Hawley S. L. and West A. A. 2004 PASP 116 1105
West A. A.; Morgan D. P.; Bochanski J. J. et al 2011 AJ 141 97
Wizinowich P. L.; Le Mignant D.; Bouchez A. H. et al 2006 PASP 118 297
Zwitter T. and Munari U. 2004 in RMxAA Conf. Ser.; Proc. IAU Colloq. 191, The Environment and Evolution of Double and Multiple Stars 21 251 ed C. Allen and C. Scarfe