Bibcode
Jones, D.; Boffin, H. M. J.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 466, Issue 2, p.2034-2038
Fecha de publicación:
4
2017
Número de citas
14
Número de citas referidas
11
Descripción
SuWt 2 is a planetary nebula consisting of a bright ring-like waist from
which protrude faint extended lobes - a morphology believed to be
typical of progenitors which have experienced a close-binary evolution.
Previous observations of NSV 19992, the star at the projected centre of
SuWt 2, have found it to comprise two A-type stars in a 4.9 d eclipsing
orbit, neither of which could be the nebular progenitor. Radial velocity
studies provided a hint that the systemic velocity of this double A-type
binary might be varying over time, suggesting the presence of a third
component hypothesized to be the nebular progenitor. Here, we present an
extensive radial velocity monitoring study of NSV 19992, performed with
the high-resolution Ultraviolet and Visual Echelle Spectrograph mounted
on the European Southern Observatory's Very Large Telescope, in order to
constrain the possible variation in the systemic velocity of the A-type
binary and its relation to the progenitor of SuWt 2. The observations,
acquired over a period of approximately one year, show no evidence of
variability in the systemic velocity of NSV 19992. Combining these new
observations with previous high-resolution spectroscopy demonstrates
that the systemic velocity is also stable over much longer periods and,
moreover, is distinct from that of SuWt 2, strongly indicating that the
two are not associated. We conclude that NSV 19992 is merely a field
star system, by chance lying in the same line of sight as the nebular
centre, and that it bears no relation to SuWt 2 or its, as yet
unidentified, central star(s).
Proyectos relacionados
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Antonio
Mampaso Recio