J/ApJ/886/19 Lyα obs. of low-mass stars Ross 825 & 1044 (Schneider+, 2019)
Lyα observations of high radial velocity low-mass stars Ross 1044 and
Ross 825.
Schneider A.C., Shkolnik E.L., Barman T.S., Loyd R.P.
<Astrophys. J., 886, 19 (2019)>
=2019ApJ...886...19S 2019ApJ...886...19S
ADC_Keywords: Stars, K-type; Stars, M-type; Spectra, ultraviolet
Keywords: Low mass stars
Abstract:
The discovery of habitable zone (HZ) planets around low-mass stars has
highlighted the need for a comprehensive understanding of the
radiation environments in which such planets reside. Of particular
importance is knowledge of the far-ultraviolet (FUV) radiation, as
low-mass stars are typically much more active than solar-type stars
and the proximity of their HZs can be one-tenth the distance. The vast
majority of the flux emitted by low-mass stars at FUV wavelengths
occurs in the Lyα line at 1216 Å. However, measuring a
low-mass star's Lyα emission directly is almost always
impossible because of the contaminating effects of interstellar
hydrogen and geocoronal airglow. We observed Ross825 (K3) and Ross1044
(M0), two stars with exceptional radial velocities, with the Space
Telescope Imaging Spectrograph on board the Hubble Space Telescope.
Their radial velocities resulted in significant line shifts, allowing
for a more complete view of their Lyα line profiles. We provide
an updated relation between effective temperature and Lyα flux
using Gaia DR2 astrometry as well as updated, model-independent
relationships between Lyα flux and UV flux measurements from the
Galaxy Evolution Explorer (GALEX) for low-mass stars. These new
relations, in combination with GALEX's considerable spatial coverage,
provide substantial predictive power for the Lyα environments
for thousands of nearby, low-mass stars.
Description:
We observed Ross 825 and Ross 1044 during HST Cycle 25 with STIS on
board HST (PID #15286). We employed the G140M grating (R∼11400) with a
52"x0.1" slit. For each observation, we set the central wavelength to
1222Å. Observation were made on 2018 Jul 30, 2018 Aug 3 for Ross825
and on 2018 Nov 26, 2018 Nov 30 for Ross1044.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 39 2 HST/STIS observations
fig1.dat 42 2048 HST/STIS spectra for Ross 1044 and Ross 825
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
III/119 : Spectral classifications of proper motion stars (Bidelman+ 1985)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
III/221 : Catalogue of [Fe/H] of F, G, K stars (Cayrel de Strobel+, 2001)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/331/81 : Hyades membership (Perryman+ 1998)
J/AJ/121/2148 : Precise spectral types for 372 A, F & G stars (Gray+, 2001)
J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)
J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)
J/A+A/445/939 : Metal-poor stars uvby-beta photometry. XI. (Schuster+, 2006)
J/A+A/460/695 : Associations Containing Young stars (Torres+, 2006)
J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
J/A+A/534/A58 : HD20794, HD85512, HD192310 HARPS RVs (Pepe+, 2011)
J/ApJ/761/166 : Terrestrial exoplanet atmospheres. I. (Hu+, 2012)
J/ApJ/756/46 : Lithium abundances in HIP stars (Ramirez+, 2012)
J/ApJ/748/93 : K-band spectra for 133 nearby M dwarfs (Rojas-Ayala+, 2012)
J/ApJ/758/56 : Young M dwarfs within 25pc. II. Kinematics (Shkolnik+, 2012)
J/A+A/556/A126 : GJ667C Doppler & activity data (Anglada-Escude+, 2013)
J/ApJ/771/40 : Main-sequence A, F, G & K stars photometry (Boyajian+, 2013)
J/A+A/555/A11 : DUNES survey observational results (Eiroa+, 2013)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)
J/ApJ/784/156 : Parallaxes for nearby mid-to-late M dwarfs (Dittmann+, 2014)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/ApJS/211/9 : Variability in UV line emission of F-M stars (Loyd+, 2014)
J/AJ/147/20 : Spectroscopy of 447 nearby M dwarfs (Newton+, 2014)
J/ApJ/798/41 : GALEX NUV obs. of bright M-type stars (Ansdell+, 2015)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/807/45 : Potentially habitable planets (Dressing+, 2015)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/ApJ/800/85 : Teff, radii and luminosities of cool dwarfs (Newton+, 2015)
J/MNRAS/452/2127 : Fundamental param. of Kepler stars (Silva Aguirre+, 2015)
J/A+A/585/A5 : Exoplanet hosts/field star ages (Bonfanti+, 2016)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
J/AJ/151/160 : 1103 parallaxes and proper motions from URAT (Finch+, 2016)
J/ApJS/224/2 : K2 EPIC stellar properties for 138600 targets (Huber+, 2016)
J/ApJ/817/1 : Palomar/MSU and SDSS-DR7 M dwarfs with GALEX (Jones+, 2016)
J/ApJ/834/17 : Mass & rad of planets, moons, low mass stars (Chen+, 2017)
J/AJ/153/128 : WOCS. LXXV. Hyades & Praesepe (Cummings+, 2017)
J/AJ/153/21 : Abundances in the local region. II. (Luck+, 2017)
J/AJ/154/245 : Spitzer-detected debris disks (Meshkat+, 2017)
J/ApJ/836/77 : High-S/N opt. spectra library of FGKM stars (Yee+, 2017)
J/ApJ/843/31 : MUSCLES Treasury Survey. IV. (Youngblood+, 2017)
J/A+A/614/A55 : Li abundance in dwarfs & subgiants (Aguilera-Gomez+, 2018)
J/AJ/155/149 : Co-moving stars observed by Gaia (Bochanski+, 2018)
J/AJ/155/180 : Cool dwarf targets for the TESS (Muirhead+, 2018)
J/AJ/156/102 : TESS Input Catalog & Candidate Target List (Stassun+, 2018)
J/AJ/158/75 : M dwarfs planet occurrence rates (Hardegree-Ullman+, 2019)
J/ApJ/872/17 : HAZMAT. V. (Richey-Yowell+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 21 A11 "date" Date1 First date of observation (UT)
23- 33 A11 "date" Date2 Second date of observation (UT)
35- 39 I5 s Exp [15186/17079] Exposure time
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 19 F9.4 0.1nm lambda [1194.4/1249.1] Wavelength; in Å units
21- 31 E11.4 cW/m2/nm Flux [-0.81/3.3] Observed flux;
in erg/s/cm2/Å units
33- 42 E10.4 cW/m2/nm e_Flux [1.7e-6/0.3] Uncertainty in Flux;
in erg/s/cm2/Å units
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Mar-2021