First results from the Goddard High-Resolution Spectrograph - Spectroscopic determination of stellar parameters of Melnick 42, an O3f star in the Large Magellanic Cloud

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/186109· OSTI ID:5225537

Heap, S R; Altner, B; Ebbets, D; Hubeny, I; Hutchings, J B ^[1]

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1. NASA, Goddard Space Flight Center, Greenbelt, MD (United States) NASA, Goddard Space Flight Center (United States) Computer Sciences Corp., Greenbelt, MD (United States) Ball Aerospace Systems Group, Boulder, CO (United States) NASA, Goddard Space Flight Center, Greenbelt (United States) Universities Space Research Association, Columbia, MD (United States) Dominion Astrophysical Observatory, Victoria (Canada)

GHRS and optical (ESO 3.6 m) observations of the O3f star Melnick 42 in the 30 Doradus complex are reported. A first analysis reveals that with a luminosity of 2.3 million L(solar) and a present mass of 100 M(solar), Melnick 42 is one of the most luminous and massive stars known. An estimate of abundances indicates that iron and oxygen are very likely reduced by a factor of four relative to the sun, whereas carbon is more strongly depleted and nitrogen is approximately solar. The terminal velocity of the stellar wind is 3000 km/s. The mass-loss rate is 4 {times} 10 to the {minus}6th M(solar)/yr, with a large uncertainty. The excellent quality GHRS spectrum taken in a crowded region of the LMC demonstrates the superiority of the HST for quantitative ultraviolet spectroscopy of hot stars in other galaxies. 17 refs.

• OSTI ID: 5225537
• Journal Information: Astrophysical Journal; (United States), Vol. 377; Other Information: L29-L32; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SUPERMASSIVE STARS
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
CHEMICAL COMPOSITION
ELEMENT ABUNDANCE
LUMINOSITY
MAGELLANIC CLOUDS
MASS TRANSFER
SATELLITES
STELLAR WINDS
TELESCOPES
ABUNDANCE
GALAXIES
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPECTRA
STARS
STELLAR ACTIVITY
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources