TIME-DEPENDENT NONEXTENSIVITY ARISING FROM THE ROTATIONAL EVOLUTION OF SOLAR-TYPE STARS

Nonextensive formalism is a generalization of the Boltzmann-Gibbs statistics. In this formalism, the entropic index q is a quantity characterizing the degree of nonextensivity and is interpreted as a parameter of long-memory or long-range interactions between the components of the system. Since its...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2013-11, Vol.777 (1), p.1-7
Main Authors: Silva, J R P, Nepomuceno, M M F, Soares, B B, de Freitas, D B
Format: Article
Language:English
Subjects:
Age
ANGULAR MOMENTUM
ASTRONOMY
ASTROPHYSICS
ASTROPHYSICS, COSMOLOGY AND ASTRONOMY
Bolts
CORRELATIONS
DISTRIBUTION FUNCTIONS
Formalism
INDEXES
INTERACTION RANGE
ROTATION
Rotational
Samples
STAR CLUSTERS
STAR EVOLUTION
STARS
Statistical methods
Statistics
TIME DEPENDENCE
VARIATIONS
VELOCITY
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Nonextensive formalism is a generalization of the Boltzmann-Gibbs statistics. In this formalism, the entropic index q is a quantity characterizing the degree of nonextensivity and is interpreted as a parameter of long-memory or long-range interactions between the components of the system. Since its proposition in 1988, this formalism has been applied to investigate a wide variety of natural phenomena. In stellar astrophysics, a theoretical distribution function based on nonextensive formalism (q distributions) has been successfully applied to reproduce the distribution of stellar radial and rotational velocity data. In this paper, we investigate the time variation of the entropic index q obtained from the distribution of rotation, V sin i, for a sample of 254 rotational data for solar-type stars from 11 open clusters aged between 35.5 Myr and 2.6 Gyr. As a result, we have found an anti-correlation between the entropic index q and the age of clusters, and that the distribution of rotation V sin i for these stars becomes extensive for an age greater than about 170 Myr. Assuming that the parameter q is associated with long-memory effects, we suggest that the memory of the initial angular momentum of solar-type stars can be scaled by the entropic index q. We also propose a physical link between the parameter q and the magnetic braking of stellar rotation.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/777/1/20