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Related papers: M Dwarfs from Hubble Space Telescope Star Counts. …

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We present a sample of 17 newly discovered ultracool dwarf candidates later than ~M8, drawn from 231.90 arcmin2 of {\it Hubble Space Telescope} Wide Field Camera 3 infrared imaging. By comparing the observed number counts for…

The Herschel open-time key program Disc Emission via a Bias-free Reconnaissance in the Infrared and Sub-millimeter (DEBRIS) is an unbiased survey of the nearest ~100 stars for each stellar type A-M observed with a uniform photometric…

We use the Hubble Ultra Deep Field (UDF) to study the galaxy luminosity-size (M-Re) distribution. With a careful analysis of selection effects due to both detection completeness and measurement reliability we identify bias-free regions in…

Astrophysics · Physics 2007-05-23 E. Cameron , S. P. Driver

Knowledge of stellar atmospheric parameters ($T_{\rm eff}$, $\log{g}$, [Fe/H]) of M dwarfs can be used to constrain both theoretical stellar models and Galactic chemical evolutionary models, and guide exoplanet searches, but their…

Solar and Stellar Astrophysics · Physics 2023-02-22 C. Duque-Arribas , D. Montes , H. M. Tabernero , J. A. Caballero , J. Gorgas , E. Marfil

We review observational data about a sample of Local Volume objects containing about 1000 galaxies within 11 Mpc of the Milky Way. Dwarf galaxies with stellar masses $M_*/M_{\odot} < 9$ dex make up 5/6 of the sample. Almost 40% of them have…

Astrophysics of Galaxies · Physics 2019-06-19 I. D. Karachentsev , E. I Kaisina

We study the relationship between Galactic location ($R, Z$) and photometric activity for 3.6 million M dwarf stars within 1 kpc of the Sun. For this purpose, we identify 906 unique flare events as a proxy for magnetic activity from the…

Solar and Stellar Astrophysics · Physics 2022-10-05 Seo-Won Chang , Christian Wolf , Christopher A. Onken

We obtained high resolution ELODIE and CORALIE spectra for both components of 20 wide visual binaries composed of an F-, G- or K-dwarf primary and an M-dwarf secondary. We analyse the well understood spectra of the primaries to determine…

Astrophysics · Physics 2007-05-23 X. Bonfils , X. Delfosse , S. Udry , N. C. Santos , T. Forveille , D. Ségransan

We use star counts from 13 deep HST fields imaged with the {\it Wide Field Camera - 2} in order to constrain the amount of dark matter in the Galaxy that can be in the form of low-mass main sequence stars or white-dwarfs. Based on the…

Astrophysics · Physics 2015-06-24 Basilio X. Santiago , Gerard Gilmore , Rebecca A. W. Elson

We use a new technique to search for faint red stars in the Hubble Deep Field (HDF) imaged by the Wide Field Camera (WFC2) on the {\it Hubble Space Telescope}. We construct a densely sampled stellar light profile from a set of undersampled…

Astrophysics · Physics 2009-10-28 Chris Flynn , Andrew Gould , John N. Bahcall

We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey's…

Astrophysics of Galaxies · Physics 2017-08-02 Deborah Ferguson , Susan Gardner , Brian Yanny

We present a study of the dynamics and magnetic activity of M dwarfs using the largest spectroscopic sample of low-mass stars ever assembled. The age at which strong surface magnetic activity (as traced by H-alpha) ceases in M dwarfs has…

We present a magnitude and proper motion limited catalogue of ~10,000 white dwarf candidates, obtained from the SuperCOSMOS Sky Survey by means of reduced proper motion selection. This catalogue extends to magnitudes r~19.75 and proper…

Astrophysics of Galaxies · Physics 2011-04-21 Nicholas Rowell , Nigel Hambly

We present a tally of Milky Way late-type dwarf stars in 68 WFC3 pure-parallel fields (227 arcmin^2) from the Brightest of Reionizing Galaxies (BoRG) survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two…

We analyze 166 spheroid subdwarfs $(6.5<M_V<14.5)$ found in 53 fields observed with the Wide Field Camera on the {\it Hubble Space Telescope}. The fields cover 221 square arcmin over a wide range of directions. The spheroid luminosity…

Astrophysics · Physics 2009-10-30 Andrew Gould , Chris Flynn , John N. Bahcall

We present K band spectra for 133 nearby (d < 33 parsecs) M dwarfs, including 18 M dwarfs with reliable metallicity estimates (as inferred from an FGK type companion), 11 M dwarf planet hosts, more than 2/3 of the M dwarfs in the Northern 8…

Solar and Stellar Astrophysics · Physics 2012-03-15 Bárbara Rojas-Ayala , Kevin R. Covey , Philip S. Muirhead , James P. Lloyd

We present the techniques and early results of our program to measure the luminosity function for White Dwarfs in the SuperCOSMOS Sky Survey. Our survey covers over three quarters of the sky to a mean depth of I~19.2, and finds ~9,500…

Solar and Stellar Astrophysics · Physics 2009-07-22 N. R. Rowell , N. C. Hambly , P. Bergeron

Using the data release 1 of the Hyper Suprime-Cam Subaru Strategic Program covering about 130 square degrees at high galactic latitudes, we have obtained L dwarf counts based on the selection criteria on colors, limiting magnitude and PSF…

Astrophysics of Galaxies · Physics 2019-01-23 Satoko Sorahana , Tadashi Nakajima , Yoshiki Matsuoka

While M dwarfs are the most abundant stars in the Milky Way, there is still large uncertainty about their basic physical properties (mass, luminosity, radius, etc.) as well as their formation environment. Precise knowledge of multiplicity…

Solar and Stellar Astrophysics · Physics 2015-05-19 C. Bergfors , W. Brandner , M. Janson , S. Daemgen , K. Geissler , T. Henning , S. Hippler , F. Hormuth , V. Joergens , R. Köhler

The mass-luminosity relation for late-type stars has long been a critical tool for estimating stellar masses. However, there is growing need for both a higher-precision relation and a better understanding of systematic effects (e.g.,…

M dwarfs with masses 0.1 <= M/M_sol <= 0.3 are under increasing scrutiny because these fully convective stars pose interesting astrophysical questions regarding their magnetic activity and angular momentum history. They also afford the most…

Solar and Stellar Astrophysics · Physics 2021-01-20 Jennifer G. Winters , David Charbonneau , Todd J. Henry , Jonathan M. Irwin , Wei-Chun Jao , Adric R. Riedel , Kenneth Slatten