1997A&A...318L...9V


Query : 1997A&A...318L...9V

1997A&A...318L...9V - Astronomy and Astrophysics, volume 318, L9-12 (1997/2-1)

An active K0 IV-V star and a hot white dwarf (EUVE J0702+129) in a wide binary.

VENNES S., CHRISTIAN D.J., MATHIOUDAKIS M. and DOYLE J.G.

Abstract (from CDS):

We present far ultraviolet and optical spectroscopy of the Extreme Ultraviolet Explorer (EUVE) survey source EUVE J0702+129 revealing a composite K0 star plus DA white dwarf spectrum. The International Ultraviolet Explorer spectra show continuum emission from a hot white dwarf (Teff=30-40,000K) and a rising contribution from the K0 star at λ>2500Å. High resolution optical spectroscopy uncovers a high level of activity with strong Hα and Ca H&K emission; application of the Wilson-Bappu relation indicates that the secondary star is slightly above the main sequence (K0 IV-V). Both objects are found at a distance of ∼130pc and they likely constitute a physical pair. The EUV emission is dominated by the white dwarf, but the late-type star certainly contributes at higher energy. An interesting parallel is drawn with other DA+K0 pairs with moderately active secondaries such as HD 18131 and HR 1608. The present discovery as well as other recent ones demonstrate the existence of a large population of white dwarfs hidden by evolved companions (III-IV).

Abstract Copyright:

Journal keyword(s): binaries: general - Stars: chromospheres - Stars: evolution - white dwarfs - Stars: individual: EUVE J0702+12.9

Simbad objects: 5

goto View the references in ADS

Number of rows : 5
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 HD 18131 Ro* 02 54 38.8273538856 -05 19 50.946069432   8.32 7.31     K0IV+DA: 61 0
2 V* V1092 Tau BY* 03 57 05.8117608072 +28 37 51.611231892   12.61 11.51 10.92   K2V+DA1.5 47 0
3 * 63 Eri SB* 04 59 50.4534782856 -10 15 47.916588204   6.180 5.390     G4IV-V+DA 102 1
4 RX J0702.0+1257 XB* 07 02 03.9576564696 +12 57 54.756483372   11.28 10.470   9.543 K0IV-Ve+DA 28 0
5 UCAC3 206-77265 * 07 02 04.1597932944 +12 58 00.874741908     14.0 13.36   K4V 1 0

To bookmark this query, right click on this link: simbad:objects in 1997A&A...318L...9V and select 'bookmark this link' or equivalent in the popup menu


2022.05.22-07:17:03

© Université de Strasbourg/CNRS

    • Contact