<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Osten, Rachel A.</style></author><author><style face="normal" font="default" size="100%">Kowalski, Adam</style></author><author><style face="normal" font="default" size="100%">Drake, Stephen A.</style></author><author><style face="normal" font="default" size="100%">Krimm, Hans</style></author><author><style face="normal" font="default" size="100%">Page, Kim</style></author><author><style face="normal" font="default" size="100%">Gazeas, Kosmas</style></author><author><style face="normal" font="default" size="100%">Kennea, Jamie</style></author><author><style face="normal" font="default" size="100%">Oates, Samantha</style></author><author><style face="normal" font="default" size="100%">Page, Mathew</style></author><author><style face="normal" font="default" size="100%">de Miguel, Enrique</style></author><author><style face="normal" font="default" size="100%">Novák, Rudolf</style></author><author><style face="normal" font="default" size="100%">Apeltauer, Tomas</style></author><author><style face="normal" font="default" size="100%">Gehrels, Neil</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf Binary System DG CVn</style></title><short-title><style face="normal" font="default" size="100%">The Astrophysical Journal</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Astrophysics - High Energy Astrophysical Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Astrophysics - Solar and Stellar Astrophysics</style></keyword><keyword><style  face="normal" font="default" size="100%">stars: coronae</style></keyword><keyword><style  face="normal" font="default" size="100%">stars: flare</style></keyword><keyword><style  face="normal" font="default" size="100%">stars: individual: DG CVn</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2016/12/1</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://ui.adsabs.harvard.edu/abs/2016ApJ...832..174O</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">832</style></volume><pages><style face="normal" font="default" size="100%">174</style></pages><isbn><style face="normal" font="default" size="100%">0004-637X</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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 &lt;SUB&gt; X &lt;/SUB&gt; 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 &gt;10&lt;SUP&gt;20&lt;/SUP&gt; cm&lt;SUP&gt;2&lt;/SUP&gt;, 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 ∼ 10&lt;SUP&gt;4&lt;/SUP&gt; 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 × 10&lt;SUP&gt;35&lt;/SUP&gt; and 9 × 10&lt;SUP&gt;35&lt;/SUP&gt; erg, and optical flare energies at E &lt;SUB&gt; V &lt;/SUB&gt; of 2.8 × 10&lt;SUP&gt;34&lt;/SUP&gt; and 5.2 × 10&lt;SUP&gt;34&lt;/SUP&gt; 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.</style></abstract></record></records></xml>