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Title: FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA

Abstract

We present a spectroscopic method for diagnosing a low-frequency electrostatic plasma turbulence (LEPT) in plasmas of flare stars. This method had been previously developed by one of us and successfully applied to diagnosing the LEPT in solar flares. In distinction to our previous applications of the method, here we use the latest advances in the theory of the Stark broadening of hydrogen spectral lines. By analyzing observed emission Balmer lines, we show that it is very likely that the LEPT was developed in several flares of AD Leo, as well as in one flare of EV Lac. We found the LEPT (though of different field strengths) both in the explosive/impulsive phase and at the phase of the maximum, as well as at the gradual phase of the stellar flares. While for solar flares our method allows diagnosing the LEPT only in the most powerful flares, for the flare stars it seems that the method allows revealing the LEPT practically in every flare. It should be important to obtain new and better spectrograms of stellar flares, allowing their analysis by the method outlined in the present paper. This can be the most favorable way to the detailed understanding of the nature of nonthermal astrophysical phenomena.

Authors:
 [1];  [2]
  1. Physics Department, 206 Allison Lab., Auburn University, Auburn, AL 36849 (United States)
  2. Crimean Astrophysical Observatory, Nauchny, Bakhchisaray region, Crimea, 298409 (Russian Federation)
Publication Date:
OSTI Identifier:
22521495
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 819; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; BALMER LINES; EV RANGE; HYDROGEN; LINE BROADENING; PLASMA; SOLAR FLARES; SUN; TURBULENCE

Citation Formats

Oks, E., and Gershberg, R. E. FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA. United States: N. p., 2016. Web. doi:10.3847/0004-637X/819/1/16.
Oks, E., & Gershberg, R. E. FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA. United States. https://doi.org/10.3847/0004-637X/819/1/16
Oks, E., and Gershberg, R. E. 2016. "FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA". United States. https://doi.org/10.3847/0004-637X/819/1/16.
@article{osti_22521495,
title = {FLARE STARS—A FAVORABLE OBJECT FOR STUDYING MECHANISMS OF NONTHERMAL ASTROPHYSICAL PHENOMENA},
author = {Oks, E. and Gershberg, R. E.},
abstractNote = {We present a spectroscopic method for diagnosing a low-frequency electrostatic plasma turbulence (LEPT) in plasmas of flare stars. This method had been previously developed by one of us and successfully applied to diagnosing the LEPT in solar flares. In distinction to our previous applications of the method, here we use the latest advances in the theory of the Stark broadening of hydrogen spectral lines. By analyzing observed emission Balmer lines, we show that it is very likely that the LEPT was developed in several flares of AD Leo, as well as in one flare of EV Lac. We found the LEPT (though of different field strengths) both in the explosive/impulsive phase and at the phase of the maximum, as well as at the gradual phase of the stellar flares. While for solar flares our method allows diagnosing the LEPT only in the most powerful flares, for the flare stars it seems that the method allows revealing the LEPT practically in every flare. It should be important to obtain new and better spectrograms of stellar flares, allowing their analysis by the method outlined in the present paper. This can be the most favorable way to the detailed understanding of the nature of nonthermal astrophysical phenomena.},
doi = {10.3847/0004-637X/819/1/16},
url = {https://www.osti.gov/biblio/22521495}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 819,
place = {United States},
year = {Tue Mar 01 00:00:00 EST 2016},
month = {Tue Mar 01 00:00:00 EST 2016}
}