Brown dwarts: A possible missing link between stars and planets

Science

Volumn 276, Issue 5317, 1997, Pages 1350-1354

  Kulkarni, S R ^a  

^a CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ARTICLE; ASTRONOMY; COSMOS; INFRARED RADIATION; NUCLEAR ENERGY AND RELATED PHENOMENA; PHYSICS; PRIORITY JOURNAL;

EID: 0030998346     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.276.5317.1350     Document Type: Article

References (39)

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37. It is worth remarking here that there is still considerable uncertainty about the nature of the dimmest stars. There have been repeated suggestions that some of the VLM stars are brown dwarfs. The observed high luminosity of these objects would require them to be young brown dwarfs. A number of objects which are ostensibly not members of star forming regions show Li absorption [B. R. Oppenheimer, G. Basri, T. Nakajima, S. R. Kulkarni, Astron. J. 113, 296 (1997). Similar results by R. Neuhauser, in Reviews of Modern Astronomy, R. Shcilicke, Ed. (1997), vol. 10.]. However, there is no indication of a population of field brown dwarfs with luminosity between those of Tiede 1 and Gliese 229B. Such a population would be expected in steady state. Most likely, star formation is not as clustered as has been assumed and the dim stars are all VLM stars. If not, there could be more diversity in the substellar transition region than indicated by our theoretical models.
38. It is worth remarking here that there is still considerable uncertainty about the nature of the dimmest stars. There have been repeated suggestions that some of the VLM stars are brown dwarfs. The observed high luminosity of these objects would require them to be young brown dwarfs. A number of objects which are ostensibly not members of star forming regions show Li absorption [B. R. Oppenheimer, G. Basri, T. Nakajima, S. R. Kulkarni, Astron. J. 113, 296 (1997). Similar results by R. Neuhauser, in Reviews of Modern Astronomy, R. Shcilicke, Ed. (1997), vol. 10.]. However, there is no indication of a population of field brown dwarfs with luminosity between those of Tiede 1 and Gliese 229B. Such a population would be expected in steady state. Most likely, star formation is not as clustered as has been assumed and the dim stars are all VLM stars. If not, there could be more diversity in the substellar transition region than indicated by our theoretical models.
39. I thank J. Gizis, T. Nakajima and T. Padmanabhan for constructive comments on the text. I am grateful to F. Allard, G. Basri, A. Burrows, C. Koresko and B. Oppenheimer for a thorough reading and comments. I have benefitted (and hopefully it shows up in this review) by attending the Tenerife meeting on Brown Dwarfs and Extrasolar Planets (5). I thank E. Martin and R. Rebolo for defraying some costs associated with my attendance of this meeting. My research in brown dwarfs has been done in collaboration with S. Durrance, D. Golimowski, K. Matthews T. Nakajima and B. Oppenheimer. I particularly wish to thank T. Nakajima for getting me interested in brown dwarfs during his postdoctoral stay at Caltech and the Flintridge Foundation for providing the seed money to pursue high-dynamic range imaging at optical and IR wavelengths.