J/other/RMxAA/53.439 Gaia stars with GALEX NUV excess (Makarov, 2017)
Absolute NUV magnitudes of Gaia DR1 astrometric stars and a search for hot
companions in nearby systems.
Makarov V.V.
<Rev. Mex. Astron. Astrofis., 53, 439-448 (2017)>
=2017RMxAA..53..439M 2017RMxAA..53..439M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, double and multiple ; Stars, white dwarf ;
Ultraviolet
Keywords: binaries: general - Hertzsprung-Russell and C-M diagrams -
stars: activity - white dwarfs
Abstract:
Accurate parallaxes from Gaia DR1 (TGAS) are combined with GALEX
visual Nuv magnitudes to produce absolute MNUV magnitudes and an
ultraviolet HR diagram for a large sample of astrometric stars. A
functional fit is derived of the lower envelope main sequence of the
nearest 1403 stars (distance <40pc), which should be reddening-free.
Using this empirical fit, 50 nearby stars are selected with
significant Nuv excess. These are predominantly late K and early M
dwarfs, often associated with X-ray sources, and showing other
manifestations of magnetic activity. The sample may include systems
with hidden white dwarfs, stars younger than the Pleiades, or, most
likely, tight interacting binaries of the BY Dra-type. A separate
collection of 40 stars with precise trigonometric parallaxes and Nuv-G
colors bluer than 2mag is presented. It includes several known novae,
white dwarfs, and binaries with hot subdwarf (sdOB) components, but
most remain unexplored.
Description:
Identities, coordinates, astrometric and photometric data from the
Gaia DR1 and GALEX all-sky catalogs for stars with significant NUV
excess, indicating chromospheric activity in tight binaries, young
age, or hot companions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 50 Nearby Dwarfs (distance <40pc) with
excess Nuv luminosity
table2.dat 84 40 Gaia stars with significant parallaxes and
NUV-G colors less than 2mag
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg Right ascension (ICRS) at epoch 2015.0
12- 20 F9.5 deg DEdeg Declination (ICRS) at epoch 2015.0
22- 27 I6 --- HIP ? Hipparcos ID
29- 39 A11 --- TYC2 Tycho-2 ID
41- 46 F6.2 mas plx Gaia parallax
48- 51 F4.2 mas e_plx Gaia parallax error
53- 58 F6.3 mag Gmag Gaia G magnitude
60- 65 F6.3 mag FUV ? GALEX FUV magnitude
67- 72 F6.3 mag NUV GALEX NUV magnitude
74- 78 F5.3 mag e_FUV ? GALEX FUV magnitude error
80- 84 F5.3 mag e_NUV GALEX NUV magnitude error
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Acknowledgements:
Valeri Makarov, valeri.makarov(at)navy.mil
(End) Patricia Vannier [CDS] 09-Nov-2017