Analytic Models of Brown Dwarfs and the Substellar Mass Limit
Joint Authors
Auddy, Sayantan
Basu, Shantanu
Valluri, S. R.
Source
Issue
Vol. 2016, Issue 2016 (31 Dec. 2016), pp.1-15, 15 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2016-10-10
Country of Publication
Egypt
No. of Pages
15
Main Subjects
Abstract EN
We present the analytic theory of brown dwarf evolution and the lower mass limit of the hydrogen burning main-sequence stars and introduce some modifications to the existing models.
We give an exact expression for the pressure of an ideal nonrelativistic Fermi gas at a finite temperature, therefore allowing for nonzero values of the degeneracy parameter.
We review the derivation of surface luminosity using an entropy matching condition and the first-order phase transition between the molecular hydrogen in the outer envelope and the partially ionized hydrogen in the inner region.
We also discuss the results of modern simulations of the plasma phase transition, which illustrate the uncertainties in determining its critical temperature.
Based on the existing models and with some simple modification, we find the maximum mass for a brown dwarf to be in the range 0.064 M ⊙ – 0.087 M ⊙ .
An analytic formula for the luminosity evolution allows us to estimate the time period of the nonsteady state (i.e., non-main-sequence) nuclear burning for substellar objects.
We also calculate the evolution of very low mass stars.
We estimate that ≃11% of stars take longer than 1 0 7 yr to reach the main sequence, and ≃5% of stars take longer than 1 0 8 yr.
American Psychological Association (APA)
Auddy, Sayantan& Basu, Shantanu& Valluri, S. R.. 2016. Analytic Models of Brown Dwarfs and the Substellar Mass Limit. Advances in Astronomy،Vol. 2016, no. 2016, pp.1-15.
https://search.emarefa.net/detail/BIM-1079400
Modern Language Association (MLA)
Auddy, Sayantan…[et al.]. Analytic Models of Brown Dwarfs and the Substellar Mass Limit. Advances in Astronomy No. 2016 (2016), pp.1-15.
https://search.emarefa.net/detail/BIM-1079400
American Medical Association (AMA)
Auddy, Sayantan& Basu, Shantanu& Valluri, S. R.. Analytic Models of Brown Dwarfs and the Substellar Mass Limit. Advances in Astronomy. 2016. Vol. 2016, no. 2016, pp.1-15.
https://search.emarefa.net/detail/BIM-1079400
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1079400