OSU Navigation Bar

The Ohio State University University Libraries Knowledge Bank

The Knowledge Bank is scheduled for regular maintenance on Sunday, April 20th, 8:00 am to 12:00 pm EDT. During this time users will not be able to register, login, or submit content.

Nova Sagittarii 1994 1 (V4332 Sagittarii): The Discovery and Evolution of an Unusual Luminous Red Variable Star

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/48207

Show full item record

Files Size Format View
fac_MartiniP_Th ... lJournal_1999_118_1034.pdf 413.5Kb PDF View/Open

Title: Nova Sagittarii 1994 1 (V4332 Sagittarii): The Discovery and Evolution of an Unusual Luminous Red Variable Star
Creators: Martini, Paul; Wagner, R. Mark; Tomaney, Austin; Rich, R. Michael; Valle, M. Della; Hauschildt, Peter H.
Keywords: stars: evolution
stars: variables: other
Issue Date: 1999-08
Publisher: American Astronomical Society
Citation: Paul Martini et al, "Nova Sagittarii 1994 1 (V4332 Sagittarii): The Discovery and Evolution of an Unusual Luminous Red Variable Star," The Astronomical Journal 118, no. 2 (1999), doi:10.1086/300951
DOI: 10.1086/300951
Abstract: We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst with known classes of outbursts—including classical novae and outbursts occurring on symbiotic stars—and find this object does not conform to any known class of outburst. The closest match to the behavior of this unusual object is M31 RV, an extremely luminous and red variable object discovered in the bulge of M31 in 1988. However, the temporal behavior and maximum luminosity of the two events differ by several orders of magnitude, requiring substantial intrinsic variation if these two events are members the same type of outburst. Our model of the spectroscopic evolution of this outburst shows that the effective temperature cooled from 4400 to 2300 K over the 3 month span of our observations. In combination with line diagnostics in our later spectra, including [O I] λ5577 and the dramatic increase in the Hα-to-Hβ ratio, we infer the existence of a cool, dense (N_e ~ 108–109 cm^-3) envelope that is optically thick in the hydrogen Balmer recombination lines (case C). We suggest that a nuclear event in a single star, in which a slow shock drove the photosphere outward, can power the observed luminosity evolution and the emission spectrum.
ISSN: 1538-3881
URI: http://hdl.handle.net/1811/48207
Bookmark and Share