2015MNRAS.448.3567K


Query : 2015MNRAS.448.3567K

2015MNRAS.448.3567K - Mon. Not. R. Astron. Soc., 448, 3567-3571 (2015/April-3)

Discovery of blue companions to two southern Cepheids: WW Car and FN Vel.

KOVTYUKH V., SZABADOS L., CHEKHONADSKIKH F., LEMASLE B. and BELIK S.

Abstract (from CDS):

A large number of high-dispersion spectra of classical Cepheids were obtained in the region of the Ca ii H+K spectral lines. The analysis of these spectra allowed us to detect the presence of a strong Balmer line, Hε, for several Cepheids, interpreted as the signature of a blue companion: the presence of a sufficiently bright blue companion to the Cepheid results in a discernible strengthening of the Ca ii H + Hε line relative to the Ca ii K line. We investigated 103 Cepheids, including those with known hot companions (B5-B6 main-sequence stars) in order to test the method. We could confirm the presence of a companion to WW Car and FN Vel (the existence of the former was only suspected before) and we found that these companions are blue hot stars. The method remains efficient when the orbital velocity changes in a binary system cannot be revealed and other methods of binarity detection are not efficient.

Abstract Copyright: © 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2015)

Journal keyword(s): binaries: spectroscopic - stars: individual: FN Velorum - stars: individual: WW Carinae - stars: variables: Cepheids

Simbad objects: 10

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Number of rows : 10
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 V* FN Vel cC* 09 48 41.4894764448 -55 31 10.350795792   11.24 10.25     F9II+? 61 0
2 V* WW Car cC* 10 51 35.7678373728 -59 23 06.014351904   10.55 9.68     F9II+? 91 1
3 V* S Mus cC* 12 12 47.0199008472 -70 09 06.439196664 7.58 8.80 8.33 7.39 5.196 F6Ib+B5V 275 0
4 V* V659 Cen cC* 13 31 33.4105951824 -61 34 56.518628628 7.57 7.19 6.49     F6/7Ib+B6V 120 0
5 V* KN Cen cC* 13 36 36.8950655064 -64 33 29.914949592   11.22 9.86     G8Iab+B6.0V 157 0
6 V* BP Cir cC* 14 46 41.9805572256 -61 27 42.991255656   8.12 7.52     F2/3II+B6V 102 0
7 * 26 Cir cC* 14 52 35.2587595008 -63 48 35.356730796   6.66 5.96   4.993 F8II 154 0
8 V* SY Nor cC* 15 54 42.8132408112 -54 33 59.158876428   11.12 9.77 9.73 7.928 F9Ib+B4.5V 116 0
9 V* V636 Sco cC* 17 22 46.4815445448 -45 36 51.401229048   7.67 6.74   5.654 F7/8Ib/II 170 1
10 V* V1334 Cyg cC* 21 19 22.1791528656 +38 14 14.868825648   6.364 5.882     F1II+B7.0V 211 0

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