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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 (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:
FileName Lrecl Records Explanations
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
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
Bytes Format Units Label Explanations
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
Acknowledgements: Valeri Makarov, valeri.makarov(at)
(End) Patricia Vannier [CDS] 09-Nov-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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