Results 21 to 30 of about 23,116,162 (197)

THE CLOSE BINARY FRACTION OF DWARF M STARS [PDF]

The Astrophysical Journal, 2011
We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey (SDSS) to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs.
Clark, Benjamin M., Blake, Cullen H., Knapp, Gillian R.   +2 more
openaire   +3 more sources

The SPHINX M-dwarf Spectral Grid. I. Benchmarking New Model Atmospheres to Derive Fundamental M-dwarf Properties

The Astrophysical Journal, 2023
About 70%–80% of stars in our solar and Galactic neighborhood are M dwarfs. They span a range of low masses and temperatures relative to solar-type stars, facilitating molecule formation throughout their atmospheres.
Aishwarya R. Iyer, Michael R. Line, Philip S. Muirhead, Jonathan J. Fortney, Ehsan Gharib-Nezhad   +4 more
doaj   +1 more source

Single-hemisphere Dynamos in M-dwarf Stars

The Astrophysical Journal Letters, 2020
Abstract M-dwarf stars below a certain mass are convective from their cores to their photospheres. These fully convective objects are extremely numerous, very magnetically active, and the likely hosts of many exoplanets. Here we study, for the first time, dynamo action in simulations of stratified, rotating, fully convective M-dwarf ...
Benjamin P. Brown, Jeffrey S. Oishi, Geoffrey M. Vasil, Daniel Lecoanet, Keaton J. Burns   +4 more
openaire   +2 more sources

Hot DAVs: a probable new class of pulsating white dwarf stars [PDF]

, 2013
We have discovered a pulsating DA white dwarf at the lower end of the temperature range 45 000–30 000 K where a few helium atmosphere white dwarfs are known. There are now three such pulsators known, suggesting that a new class of theoretically predicted
Gansicke, B. T., Marsh, Tom, Kurtz, D.W., Copperwheat, Chris M., Kurtz, Donald Wayne, Copperwheat, C.M., Copperwheat, C. M., Gaensicke, B. T., Littlefair, Stuart P., Dhillon, V. S., Littlefair, S.P., Parsons, Steven G., Parsons, S. G., Kurtz, D. W., Gänsicke, B.T., Parsons, S.G., Marsh, T.R., Dhillon, Vik S., Dhillon, V.S., Littlefair, S. P., Shibahashi, H., Marsh, T. R.   +21 more
core   +1 more source

Atmospheres of brown dwarfs [PDF]

, 2014
ChH highlights financial support of the European Community under the FP7 by an ERC starting grant. SLC acknowledges financial support of University of LeicesterBrown Dwarfs are the coolest class of stellar objects known to date. Our present perception is
Casewell, Sarah, Helling, Christiane
core   +1 more source

TOI 4201 b and TOI 5344 b: Discovery of Two Transiting Giant Planets around M-dwarf Stars and Revised Parameters for Three Others

The Astronomical Journal, 2023
We present the discovery from the TESS mission of two giant planets transiting M-dwarf stars: TOI 4201 b and TOI 5344 b. We also provide precise radial velocity measurements and updated system parameters for three other M dwarfs with transiting giant ...
J. D. Hartman, G. Á. Bakos, Z. Csubry, A. W. Howard, H. Isaacson, S. Giacalone, A. Chontos, N. Narita, A. Fukui, J. P. de Leon, N. Watanabe, M. Mori, T. Kagetani, I. Fukuda, Y. Kawai, M. Ikoma, E. Palle, F. Murgas, E. Esparza-Borges, H. Parviainen, L. G. Bouma, M. Cointepas, X. Bonfils, J. M. Almenara, Karen A. Collins, Kevin I. Collins, Howard M. Relles, Khalid Barkaoui, Richard P. Schwarz, Ghachoui Mourad, Mathilde Timmermans, Georgina Dransfield, Artem Burdanov, Julien de Wit, Emmanuël Jehin, Amaury H. M. J. Triaud, Michaël Gillon, Zouhair Benkhaldoun, Keith Horne, Ramotholo Sefako, A. Jordán, R. Brahm, V. Suc, Steve B. Howell, E. Furlan, J. E. Schlieder, D. Ciardi, T. Barclay, E. J. Gonzales, I. Crossfield, C. D. Dressing, M. Goliguzova, A. Tatarnikov, George R. Ricker, Roland Vanderspek, David W. Latham, S. Seager, Joshua N. Winn, Jon M. Jenkins, Stephanie Striegel, Avi Shporer, Andrew Vanderburg, Alan M. Levine, Veselin B. Kostov, David Watanabe   +64 more
doaj   +1 more source

Effects of M dwarf magnetic fields on potentially habitable planets [PDF]

, 2013
A.A.V. acknowledges support from the Royal Astronomical Society through a post-doctoral fellowship. J.M. acknowledges support from a fellowship of the Alexander von Humboldt foundation. P.L. acknowledges funding from a STFC scholarship.
Morin, J., J.-F. Donati, Russell, A.J.B., P. Lang, Donati, J. -F., Jardine, M., A. A. Vidotto, M. Jardine, Morin, Julien, Donati, J.-F., Lang, P., Vidotto, A. A., Russell, A. J. B., Donati, J., Vidotto, A., A. J. B. Russell, J. Morin, Vidotto, A.A., Russell, A., J. -f. Donati   +19 more
core   +1 more source

WTS: A near-infrared transit survey

EPJ Web of Conferences, 2013
The WFCAM Transit Survey is a transiting planet survey running on the United Kingdom Infrared Telescope targeting M dwarf stars in the near infrared. The survey has been operating since 2007 and gathering photometric time series of about 15000 M dwarf ...
Hodgkin Simon, Kovács Gábor, Sipőcz Brigitta, Pinfield David   +3 more
doaj   +1 more source

Statistical Signatures of Nanoflare Activity. III. Evidence of Enhanced Nanoflaring Rates in Fully Convective stars as Observed by the NGTS

The Astrophysical Journal, 2023
Previous examinations of fully convective M-dwarf stars have highlighted enhanced rates of nanoflare activity on these distant stellar sources. However, the specific role the convective boundary, which is believed to be present for spectral types earlier
S. D. T. Grant, D. B. Jess, C. J. Dillon, M. Mathioudakis, C. A. Watson, J. A. G. Jackman, D. G. Jackson, P. J. Wheatley, M. R. Goad, S. L. Casewell, D. R. Anderson, M. R. Burleigh, R. G. West, J. I. Vines   +13 more
doaj   +1 more source

Living with a Red Dwarf: X-Ray, UV, and Ca ii Activity–Age Relationships of M Dwarfs

The Astrophysical Journal, 2023
The vast majority of stars in the nearby stellar neighborhood are M dwarfs. Their low masses and luminosities result in slow rates of nuclear evolution and minimal changes to the stars’ observable properties, even along astronomical timescales.
Scott G. Engle
doaj   +1 more source