Publication detail

A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf Binary System DG CVn

OSTEN, R. KOWALSKI, A. DRAKE, S. KRIMM, H. PAGE, K. GAZEAS, K. KENNEA, J. OATES, S. PAGE, M. DE MIGUEL, E. NOVÁK, R. APELTAUER, T. GEHRELS, N.

Original Title

A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf Binary System DG CVn

Type

journal article in Web of Science

Language

English

Original Abstract

On 2014 April 23, the Swift satellite responded to a hard X-ray transient detected by its Burst Alert Telescope, which turned out to be a stellar flare from a nearby, young M dwarf binary DG CVn. We utilize observations at X-ray, UV, optical, and radio wavelengths to infer the properties of two large flares. The X-ray spectrum of the primary outburst can be described over the 0.3–100 keV bandpass by either a single very high-temperature plasma or a nonthermal thick-target bremsstrahlung model, and we rule out the nonthermal model based on energetic grounds. The temperatures were the highest seen spectroscopically in a stellar flare, at T X of 290 MK. The first event was followed by a comparably energetic event almost a day later. We constrain the photospheric area involved in each of the two flares to be >1020 cm2, and find evidence from flux ratios in the second event of contributions to the white light flare emission in addition to the usual hot, T ~ 104 K blackbody emission seen in the impulsive phase of flares. The radiated energy in X-rays and white light reveal these events to be the two most energetic X-ray flares observed from an M dwarf, with X-ray radiated energies in the 0.3–10 keV bandpass of 4 × 1035 and 9 × 1035 erg, and optical flare energies at E V of 2.8 × 1034 and 5.2 × 1034 erg, respectively. The results presented here should be integrated into updated modeling of the astrophysical impact of large stellar flares on close-in exoplanetary atmospheres.

Keywords

stars coronae; stars flare; stars individual (DG CVn)

Authors

OSTEN, R.; KOWALSKI, A.; DRAKE, S.; KRIMM, H.; PAGE, K.; GAZEAS, K.; KENNEA, J.; OATES, S.; PAGE, M.; DE MIGUEL, E.; NOVÁK, R.; APELTAUER, T.; GEHRELS, N.

Released

1. 12. 2016

Publisher

American Astronomical Society

Location

Washington

ISBN

0004-637X

Periodical

ASTROPHYSICAL JOURNAL

Year of study

832

Number

2

State

United States of America

Pages from

1

Pages to

47

Pages count

47

URL

http://iopscience.iop.org/journal/0004-637X

BibTex

@article{BUT131389,
  author="Rachel A. {Osten} and Adam {Kowalski} and Stephen A. {Drake} and Hans {Krimm} and Kim {Page} and Kosmas {Gazeas} and Jamie {Kennea} and Samantha {Oates} and Mathew {Page} and Enrique {de Miguel} and Rudolf {Novák} and Tomáš {Apeltauer} and Neil {Gehrels}",
  title="A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf Binary System DG CVn",
  journal="ASTROPHYSICAL JOURNAL",
  year="2016",
  volume="832",
  number="2",
  pages="1--47",
  doi="10.3847/0004-637X/832/2/174",
  issn="0004-637X",
  url="http://iopscience.iop.org/journal/0004-637X"
}