INVESTIGADORES
GAMEN Roberto Claudio
artículos
Título:
Further Results from the Galactic O-Star Spectroscopic Survey: Rapidly Rotating Late ON Giants
Autor/es:
WALBORN, N.; MAÍZ APELLÁNIZ, J.; SOTA, A.; ALFARO, E.; MORRELL, N. I.; BARBÁ, R.; ARIAS, J.; GAMEN, R. C.
Revista:
ASTROPHYSICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Año: 2011 vol. 142 p. 150 - 157
ISSN:
0004-637X
Resumen:
With new data from the Galactic O-Star Spectroscopic Survey, we confirm
and expand the ONn category of late-O, nitrogen-enriched (N), rapidly
rotating (n) giants. In particular, we have discovered two "clones" (HD
102415 and HD 117490) of one of the most rapidly rotating O stars
previously known (HD 191423, "Howarth's Star"). We compare the locations
of these objects in the theoretical H-R diagram to those of slowly
rotating ON dwarfs and supergiants. All ON giants known to date are
rapid rotators, whereas no ON dwarf or supergiant is, but all ON stars
are small fractions of their respective
spectral-type/luminosity-class/rotational subcategories. The ONn giants,
displaying both substantial processed material and high rotation at an
intermediate evolutionary stage, may provide significant information
about the development of these properties. They may have preserved high
initial rotational velocities or may have been spun up by terminal-age
main-sequence core contraction; alternatively, and perhaps more likely,
they may be products of binary mass transfer. At least some of them are
also runaway stars.