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Related papers: A search for variability in brown dwarfs and L dwa…

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(abridged) We perform photometric time-series analysis of a sample of ten early to mid-L dwarfs in the field over three years of $K_s$-band observations with the OMEGA 2000 infrared camera of the 3.5m telescope on Calar Alto Observatory…

Solar and Stellar Astrophysics · Physics 2015-06-22 Belén López Martí , María Rosa Zapatero Osorio

We use ~12,000 spectra of ~3,500 magnetically active M0-M9 dwarfs from the Sloan Digital Sky Survey taken at 10-15 minute intervals, together with ~300 spectra of ~60 M0-M8 stars obtained hourly with the Hydra multi-object spectrometer, to…

Solar and Stellar Astrophysics · Physics 2015-06-03 Keaton J. Bell , Eric J. Hilton , James R. A. Davenport , Suzanne L. Hawley , Andrew A. West , Allen B. Rogel

From a series of 5 GHz VLBA radio observations taken over 1-yr span, we present the detection of compact highly-polarized radio emission from the T6 brown dwarf WISE J112254.72+255022.2 compatible with electron cyclotron maser emission.…

Solar and Stellar Astrophysics · Physics 2025-05-08 J. C. Guirado , J. B. Climent , J. D. Bergasa , M. A. Pérez-Torres , J. M. Marcaide , L. Peña-Moñino

Up to now, most planet search projects have concentrated on F to K stars. In order to considerably widen the view, we have stated a survey for planets of old, nearby brown dwarfs and very low mass stars. Using UVES, we have observed 26…

Astrophysics · Physics 2011-05-23 Eike W. Guenther , Guenther Wuchterl

In 2005, Palla & Baraffe proposed that brown dwarfs (BDs) and very low mass stars (VLMSs; <0.1 solar masses) may be unstable to radial oscillations during the pre-main-sequence deuterium burning phase. With associated periods of 1-4 hours,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Ann Marie Cody , Lynne A. Hillenbrand

The L/T transition is a critical evolutionary stage for brown dwarfs and self-luminous giant planets. L/T transition brown dwarfs are more likely to be spectroscopically variable, and their high-amplitude variability probes distributions in…

Solar and Stellar Astrophysics · Physics 2025-11-24 Madalyn F. Chapleski , Yifan Zhou

We present a photometric variability survey of young planetary-mass objects using the New Technology Telescope in the Js and Ks bands. Surface gravity plays an important role in the atmospheric structure of brown dwarfs, as young low…

We present the results of a nonadiabatic, linear stability analysis of models of very low-mass stars (VLMSs) and brown dwarfs (BDs) during the deuterium burning phase in the center. We find unstable fundamental modes with periods varying…

Astrophysics · Physics 2009-11-10 Francesco Palla , Isabelle Baraffe

Aims: We aim to study the near-infrared variability of the T8 dwarfs 2MASS J09393548-2448279 and EQ J1959-3338 by analyzing their $J$-band photometric signal, which can provide new insights into the atmospheric dynamics of cold brown…

Solar and Stellar Astrophysics · Physics 2025-04-30 P. A. Miles-Páez , S. Metchev , M. R. Zapatero Osorio , D. Martín-Carrero

In this paper we study the full sample of known Spitzer [$3.6~\mu$m] and $J$-band variable brown dwarfs. We calculate the rotational velocities, $v\sin i$, of 16 variable brown dwarfs using archival Keck NIRSPEC data and compute the…

Solar and Stellar Astrophysics · Physics 2017-06-28 Johanna M. Vos , Katelyn N. Allers , Beth A. Biller

We present here optical I-band photometric variability study down to $\simeq$ 19 mag of a young ($\sim$2-3 Myr) star-forming region IC 348 in the Perseus molecular cloud. We aim to explore the fast rotation (in the time-scales of hours) in…

Solar and Stellar Astrophysics · Physics 2020-11-25 Samrat Ghosh , Soumen Mondal , Somnath Dutta , Ramkrishna Das , Santosh Joshi , Sneh Lata , Dhrimadri Khata , Alik Panja

We present new optical and near-infrared spectra of WD0137-349; a close white dwarf - brown dwarf non-interacting binary system with a period of $\approx$114 minutes. We have confirmed the presence of H$\alpha$ emission and discovered He,…

Solar and Stellar Astrophysics · Physics 2017-08-09 E. S. Longstaff , S. L. Casewell , G. A. Wynn , P. F. L. Maxted , Ch. Helling

We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC…

Solar and Stellar Astrophysics · Physics 2015-08-06 L. Prato , G. N. Mace , E. L. Rice , I. S. McLean , J. D. Kirkpatrick , A. J. Burgasser , S. S. Kim

I report the results of a survey for low-mass (0.030 <~ M <~ 0.013 M_solar) brown dwarfs in the direction of the TW Hya association using 2MASS. Two late-M dwarfs show signs of low surface gravity and are strong candidates to be young,…

Astrophysics · Physics 2009-12-08 John E. Gizis

We present initial results from a wide-field (30,000 deg^2) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and WISE surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because…

(Summary of paper) High resolution optical spectroscopy of the white dwarf WD0137-349 reveals a weak Halpha line in emission, due to a low mass companion in a close orbit. Using this emission feature, and the narrow NLTE core of the white…

Astrophysics · Physics 2009-11-11 P. F. L. Maxted , R. Napiwotzki , P. D. Dobbie , M. R. Burleigh

We present two epochs of MPG/ESO 2.2m GROND simultaneous 6-band ($r'i'z'JHK$) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57-531906.1AB. We report here the first resolved variability monitoring…

Deep optical imaging is used to study time-domain properties of young brown dwarfs in sigma Orionis over typical rotational time-scales and to search for new substellar and planetary-mass cluster members. We used VIMOS at the VLT to monitor…

Solar and Stellar Astrophysics · Physics 2017-12-13 P. Elliott , A. Scholz , R. Jayawardhana , J. Eisloffel , E. M. Hebrard

We have obtained low-resolution optical spectra of three faint brown dwarf candidates in the Pleiades open cluster. The objects observed are Roque 12 (I=18.5), Roque 5 (I=19.7) and Roque 25 (I=21.2). The spectrum of Roque 25 does not show…

Astrophysics · Physics 2009-10-30 E. L. Martin , G. Basri , M. R. Zapatero Osorio , R. Rebolo , R. J. Garcia Lopez

We have discovered that the extremely red, low-gravity L7 dwarf 2MASS J11193254-1137466 is a 0.14" (3.6 AU) binary using Keck laser guide star adaptive optics imaging. 2MASS J11193254-1137466 has previously been identified as a likely…

Solar and Stellar Astrophysics · Physics 2017-11-10 William M. J. Best , Michael C. Liu , Trent J. Dupuy , Eugene A. Magnier