INVESTIGADORES
GAMEN Roberto Claudio
artículos
Título:
The HD 5980 Multiple System: Masses and Evolutionary Status
Autor/es:
KOENIGSBERGER, G.; MORRELL, N. I.; HILLIER, D. J.; GAMEN, R. C.; SCHNEIDER, F.; GONZÁLEZ-JIMÉNEZ, N.; LANGER, N.; BARBÁ, R.
Revista:
ASTRONOMICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2014 vol. 148 p. 62 - 75
ISSN:
0004-6256
Resumen:
New spectroscopic observations of the LBV/WR multiple system HD 5980 in
the Small Magellanic Cloud are used to address the question of the
masses and evolutionary status of the two very luminous stars in the
19.3 day eclipsing binary system. Two distinct components of the N V
4944 Å line are detected in emission and their radial velocity
variations are used to derive masses of 61 and 66 M &sun;,
under the assumption that binary interaction effects on this atomic
transition are negligible. We propose that this binary system is the
product of quasi-chemically homogeneous evolution with little or no mass
transfer. Thus, both of these binary stars may be candidates for
gamma-ray burst progenitors or even pair instability supernovae.
Analysis of the photospheric absorption lines belonging to the
third-light object in the system confirm that it consists of an O-type
star in a 96.56 day eccentric orbit (e = 0.82) around an unseen
companion. The 5:1 period ratio and high eccentricities of the two
binaries suggest that they may constitute a hierarchical quadruple
system.