TY - JOUR
T1 - Detection of a giant flare displaying quasi-periodic pulsations from a pre-main-sequence M star by the Next Generation Transit Survey
AU - Jackman, James A. G.
AU - Wheatley, Peter J.
AU - Pugh, Chloe E.
AU - Kolotkov, Dmitrii Y.
AU - Broomhall, Anne-Marie
AU - Kennedy, Grant M.
AU - Murphy, Simon J.
AU - Raddi, Roberto
AU - Burleigh, Matthew R.
AU - Casewell, Sarah L.
AU - Eigmüller, Philipp
AU - Gillen, Edward
AU - Günther, Maximilian N.
AU - Jenkins, James S.
AU - Louden, Tom
AU - McCormac, James
AU - Raynard, Liam
AU - Poppenhaeger, Katja
AU - Udry, Stéphane
AU - Watson, Christopher A.
AU - West, Richard G.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - We present the detection of an energetic flare on the pre-main sequence M3 star NGTS J121939.5-355557, which we estimate as only 2 Myr old. The flare had an energy of 3.2+{0.4}-{0.3} x 10^{36} erg and a fractional amplitude of 7.2±0.8, making it one of the most energetic flares seen on an M star. The star is also X-ray active, in the saturated regime with log L_{X}/L_{Bol} = -3.1. In the flare peak we have identified multi-mode quasi-periodic pulsations formed of two statistically significant periods of approximately 320 and 660 seconds.This flare is one of the largest amplitude events to exhibit such pulsations. The shorter period mode is observed to start after a short-lived spike in flux lasting around 30 seconds, which would not have been resolved in Kepler or TESS short cadence modes. Our data shows how the high cadence of NGTS can be used to apply solar techniques to stellar flares and identify potential causes of the observed oscillations. We also discuss the implications of this flare for the habitability of planets around M star hosts and how NGTS can aid in our understanding of this.
AB - We present the detection of an energetic flare on the pre-main sequence M3 star NGTS J121939.5-355557, which we estimate as only 2 Myr old. The flare had an energy of 3.2+{0.4}-{0.3} x 10^{36} erg and a fractional amplitude of 7.2±0.8, making it one of the most energetic flares seen on an M star. The star is also X-ray active, in the saturated regime with log L_{X}/L_{Bol} = -3.1. In the flare peak we have identified multi-mode quasi-periodic pulsations formed of two statistically significant periods of approximately 320 and 660 seconds.This flare is one of the largest amplitude events to exhibit such pulsations. The shorter period mode is observed to start after a short-lived spike in flux lasting around 30 seconds, which would not have been resolved in Kepler or TESS short cadence modes. Our data shows how the high cadence of NGTS can be used to apply solar techniques to stellar flares and identify potential causes of the observed oscillations. We also discuss the implications of this flare for the habitability of planets around M star hosts and how NGTS can aid in our understanding of this.
KW - Astrophysics - Solar and Stellar Astrophysics
U2 - 10.1093/mnras/sty3036
DO - 10.1093/mnras/sty3036
M3 - Article
SN - 0035-8711
VL - 482
SP - 5553
EP - 5566
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -