Detection of a giant white-light flare on an L2.5 dwarf with the Next Generation Transit Survey

Abstract

We present the detection of a $\Delta V\sim$ -10 flare from the ultracool L2.5 dwarf ULAS J224940.13-011236.9 with the Next Generation Transit Survey (NGTS). The flare was detected in a targeted search of late-type stars in NGTS full-frame images and represents one of the largest flares ever observed from an ultracool dwarf. This flare also extends the detection of white-light flares to stars with temperatures below 2000 K. We calculate the energy of the flare to be $3.4_{-0.7}^{+0.9}\times 10^{33}$erg, making it an order of magnitude more energetic than the Carrington event on the Sun. Our data show how the high-cadence NGTS full-frame images can be used to probe white-light flaring behaviour in the latest spectral types.

arXiv comment5 pages, 2 figures, Accepted for Publication in the Monthly Notices of the Royal Astronomical Society

References in corpus (35)

• The Sloan Digital Sky Survey: Technical Summary
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Transiting Exoplanet Survey Satellite
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• The K2 Mission: Characterization and Early results
• Models of Stars, Brown Dwarfs and Exoplanets
• The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition
• Superflares on Solar Type Stars Observed with Kepler I. Statistical Properties of Superflares
• Kepler Flares I. Active and Inactive M dwarfs
• The 0.8-14.5 micron Spectra of Mid-L to Mid-T Dwarfs: Diagnostics of Effective Temperature, Grain Sedimentation, Gas Transport, and Surface Gravity
• Kepler Flares II: The Temporal Morphology of White-Light Flares on GJ 1243
• The Next Generation Transit Survey (NGTS)
• Light and Motion in SDSS Stripe 82: The Catalogues
• Colors and Kinematics of L Dwarfs From the Sloan Digital Sky Survey
• A Flaring L5 Dwarf: The Nature of HαEmission in Very Low Mass (Sub)Stellar Objects
• BOSS Ultracool Dwarfs I: Colors and Magnetic Activity of M and L dwarfs
• The Mouse that Roared: A Superflare from the dMe Flare Star EV Lac detected by Swift and Konus-Wind
• A Catalog of Cool Dwarf Targets for the Transiting Exoplanet Survey Satellite
• The Strongest Magnetic Fields on the Coolest Brown Dwarfs
• New low-mass eclipsing binary systems in Praesepe discovered by K2
• A Panchromatic View of Brown Dwarf Aurorae
• K2 Ultracool Dwarfs Survey. III. White Light Flares are Ubiquitous in M6-L0 Dwarfs
• Kepler Monitoring of an L Dwarf I. The Photometric Period and White Light Flares
• The Brown Dwarf Kinematics Project (BDKP). IV. Radial Velocities of 85 Late-M and L dwarfs with MagE
• Photometric brown-dwarf classification. II. A homogeneous sample of 1361 L and T dwarfs brighter than J = 17.5 with accurate spectral types
• ASASSN-16ae: A Powerful White-Light Flare on an Early-L Dwarf
• K2 Ultracool Dwarfs Survey II: The White Light Flare Rate of Young Brown Dwarfs
• Do long-cadence data of {\it Kepler} satellite capture the basic properties of flares ?
• Ground-based detection of G star superflares with NGTS
• K2 Ultracool Dwarfs Survey I: Photometry of an L Dwarf Superflare
• Weather on Other Worlds. IV. H$\alpha$ emission and photometric variability are not correlated in L0$-$T8 dwarfs
• Kepler Monitoring of an L Dwarf II. Clouds with Multiyear Lifetimes
• A new L5 brown dwarf member of the Hyades cluster with chromospheric activity

Cited by in corpus (15)

• I Spy Transits and Pulsations: Empirical Variability in White Dwarfs Using Gaia and the Zwicky Transient Facility
• Stellar flares detected with the Next Generation Transit Survey
• A Study of Flares in the Ultra-Cool Regime from SPECULOOS-South
• Shallow transit follow-up from NGTS: simultaneous observations of HD106315 with 11 identical telescopes
• EXTraS discovery of an X-ray superflare from an L dwarf
• On the Correlation between L Dwarf Optical and Infrared Variability and Radio Aurorae
• High-energy spectra of LTT 1445A and GJ 486 reveal flares and activity
• Design Considerations for a Ground-Based Search for Transiting Planets around L and T Dwarfs
• The Occurrence Rate of Quiescent Radio Emission for Ultracool Dwarfs using a Generalized Semi-Analytical Bayesian Framework
• Radio Emission from Binary Ultracool Dwarf Systems
• Observation of a possible superflare on Proxima Centauri
• Statistical Signatures of Nanoflare Activity. II. A Nanoflare Explanation for Periodic Brightenings in Flare Stars observed by NGTS
• The white-light superflares from cool stars in GWAC triggers
• A huge-amplitude white-light superflare on a L0 brown dwarf discovered by GWAC survey
• New cases of super-flares on slowly rotating solar-type stars and large amplitude super-flares in G- and M-type main-sequence stars