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Related papers: Chromospheric Variability in SDSS M Dwarfs. II. Sh…

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We present a generalized analytical Bayesian framework for calculating the occurrence rate of steady emission (or absorption) in astrophysical objects. As a proof-of-concept, we apply this framework to non-flaring quiescent radio emission…

Solar and Stellar Astrophysics · Physics 2023-08-02 Melodie M. Kao , Evgenya L. Shkolnik

L dwarfs exhibit low-level, rotationally-modulated photometric variability generally associated with heterogeneous, cloud-covered atmospheres. The spectral character of these variations yields insight into the particle sizes and vertical…

Solar and Stellar Astrophysics · Physics 2017-11-15 Everett Schlawin , Adam J. Burgasser , Theodora Karalidi , John Gizis , Johanna Teske

Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents. This emission provides the only window on…

Solar and Stellar Astrophysics · Physics 2016-07-27 J. Sebastian Pineda , Gregg Hallinan , J. Davy Kirkpatrick , Garret Cotter , Melodie M. Kao , Kunal Mooley

We have undertaken a differential photometric I band search for variability in three Pleiades brown dwarfs and three very low mass field L dwarfs. Analysis of the resultant time series for the Pleiades brown dwarfs (Teide 1, Calar 3, Roque…

Astrophysics · Physics 2007-05-23 C. A. L. Bailer-Jones , R. Mundt

We present a spectroscopic catalog of 70,841 visually inspected M dwarfs from the seventh data release of the Sloan Digital Sky Survey (SDSS). For each spectrum, we provide measurements of the spectral type, a number of molecular bandheads,…

The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type…

Solar and Stellar Astrophysics · Physics 2017-01-11 Elisabeth R. Newton , Jonathan Irwin , David Charbonneau , Perry Berlind , Michael L. Calkins , Jessica Mink

This paper discusses evidence for and properties of disks associated to brown dwarfs in the star-forming region rho-Oph. We selected nine objects fr om the ISOCAM survey of Bontemps et al. (2001) that have detections in the two mid-infrared…

Astrophysics · Physics 2009-11-07 A. Natta , L. Testi , F. Comeron , E. Oliva , F. D'Antona , C. Baffa , G. Comoretto , S. Gennari

We have obtained infrared (1 to 2.5 micron) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric…

Astrophysics · Physics 2009-05-29 S. K. Leggett , F. Allard , Conard Dahn , P. H. Hauschildt , T. H. Kerr , J. Rayner

Using SofI on the 3.5m New Technology Telescope, we have conducted an extensive near-infrared monitoring survey of an unbiased sample of 69 brown dwarfs spanning the L0 and T8 spectral range, with at least one example of each spectral type.…

Solar and Stellar Astrophysics · Physics 2014-07-02 P. A. Wilson , A. Rajan , J. Patience

The properties of accretion disks around stars and brown dwarfs in the SOri cluster (age 3 Myr) are studied based on NIR time series photometry supported by MIR spectral energy distributions. We monitor ~30 young low-mass sources over 8…

Solar and Stellar Astrophysics · Physics 2015-05-13 Alexander Scholz , Xiaoying Xu , Ray Jayawardhana , Kenneth Wood , Jochen Eisloeffel , Ciara Quinn

Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying…

Solar and Stellar Astrophysics · Physics 2015-06-04 Á. Kóspál , P. Ábrahám , J. A. Acosta-Pulido , C. P. Dullemond , Th. Henning , M. Kun , Ch. Leinert , A. Moór , N. J. Turner

Radio activity has been observed in a large variety of stellar objects, including in the last few years, ultra-cool dwarfs. To explore the extent of long-term radio activity in ultra-cool dwarfs, we use data taken over an extended period of…

Astrophysics · Physics 2009-11-13 A. Antonova , J. G. Doyle , G. Hallinan , A. Golden , C. Koen

We present an analysis of the photometric variability of M dwarfs in the WFCAM Transit Survey. Although periodic lightcurve variability in low mass stars is generally dominated by photospheric star spot activity, M dwarf variability in the…

An extensive sample of M, L and T dwarfs identified in the Sloan Digital Sky Survey (SDSS) has been compiled. The sample of 718 dwarfs includes 677 new objects (629 M dwarfs, 48 L dwarfs) together with 41 that have been previously…

Astrophysics · Physics 2019-08-15 S. L. Hawley , K. R. Covey , G. R. Knapp , D. A. Golimowski , X. Fan

The inwards scattering of planetesimals towards white dwarfs is expected to be a stochastic process with variability on human time-scales. The planetesimals tidally disrupt at the Roche radius, producing dusty debris detectable as excess…

Earth and Planetary Astrophysics · Physics 2020-04-15 Laura K. Rogers , Siyi Xu , Amy Bonsor , Simon Hodgkin , Kate Y. L. Su , Ted von Hippel , Michael Jura

M dwarfs are prime targets for planet search programs, particularly of those focused on the detection and characterization of rocky planets in the habitable zone. Understanding their magnetic activity is important because it affects our…

We present results of 6 years of observations, reduced and analyzed with the same tools in a systematic way. We report completely new data for 15 objects, for 5 objects we present a new analysis of previously published results plus…

Earth and Planetary Astrophysics · Physics 2015-05-18 A. Thirouin , J. L. Ortiz , R. Duffard , P. Santos-Sanz , F. J. Aceituno , N. Morales

We present \textit{Spitzer Space Telescope} variability monitoring observations of three low-gravity L dwarfs with previous detections of variability in the near-IR, 2MASS J0045+16, 2MASS J0501-00 and 2MASS J1425-36. We detect significant,…

Using medium-band imaging from the newly released Merian Survey, we conduct a nonparametric morphological analysis of H$\alpha$ emission maps and stellar continua for a sample of galaxies with $8\lesssim\log (M_\star/M_\odot) < 10.3$ at…

We report, for the first time, photometric variability of L dwarfs in $R$ band. Out of three L1 dwarfs (2MASS 1300+19, 2MASS 1439+19, and 2MASS 1658+70) observed, we have detected R band variability in 2MASS 1300+19 and 2MASS 1439+19. The…

Astrophysics · Physics 2009-11-10 M. Maiti , S. Sengupta , P. S. Parihar , G. C. Anupama