Serendipitous discovery of radio flaring behaviour from a nearby M dwarf with MeerKAT

Abstract

We report on the detection of MKT J174641.0$-$321404, a new radio transient found in untargeted searches of wide-field MeerKAT radio images centred on the black hole X-ray binary H1743$-$322. MKT J174641.0$-$321404 is highly variable at 1.3 GHz and was detected three times during 11 observations of the field in late 2018, reaching a maximum flux density of 590 $\pm$ 60 $\mu$Jy. We associate this radio transient with a high proper motion, M dwarf star SCR~1746$-$3214 12 pc away from the Sun. Multiwavelength observations of this M dwarf indicate flaring activity across the electromagnetic spectrum, consistent with emission expected from dMe stars, and providing upper limits on quiescent brightness in both the radio and X-ray regimes. \textit{TESS} photometry reveals a rotational period for SCR~1746$-$3214 of $0.2292\pm 0.0025$ days, which at its estimated radius makes the star a rapid rotator, comparable to other low mass systems. Dedicated spectroscopic follow up confirms the star as a mid-late spectral M dwarf with clear magnetic activity indicated by strong H$\alpha$ emission. This transient's serendipitous discovery by MeerKAT, along with multiwavelength characterisation, make it a prime demonstration of both the capabilities of the current generation of radio interferometers and the value of simultaneous observations by optical facilities such as MeerLICHT. Our results build upon the literature of of M dwarfs' flaring behaviour, particularly relevant to the habitability of their planetary systems.

arXiv commentAccepted to MNRAS, 11 pages, 9 figures

References in corpus (68)

• Astropy: A Community Python Package for Astronomy
• Gaia Data Release 2. Summary of the contents and survey properties
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Gaia mission
• The Transiting Exoplanet Survey Satellite
• LOFAR: The LOw-Frequency ARray
• The SIMBAD astronomical database
• The USNO-B Catalog
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• The Revised TESS Input Catalog and Candidate Target List
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• A morphological algorithm for improving radio-frequency interference detection
• A seven-planet resonant chain in TRAPPIST-1
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime
• Stellar Radio Astronomy. Probing Stellar Atmospheres from Protostars to Giants
• Stellar Flares from the First Tess Data Release: Exploring a New Sample of M-dwarfs
• An optimized algorithm for multi-scale wideband deconvolution of radio astronomical images
• Science With The Australian Square Kilometre Array Pathfinder
• The Effective Temperature Scale of M dwarfs
• 2SXPS: An improved and expanded Swift X-ray telescope point source catalog
• A powerful bursting radio source towards the Galactic Centre
• Flaring Up All Over -- Radio Activity in Rapidly-Rotating Late-Type M and L Dwarfs
• Kepler Planet Occurrence Rates for Mid-Type M Dwarfs as a Function of Spectral Type
• 1SXPS: A deep Swift X-ray Telescope point source catalog with light curves and spectra
• Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
• Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. III. X-ray, Radio, and H-alpha Activity Trends in M and L Dwarfs
• Orphan GRB radio afterglows: Candidates and constraints on beaming
• The Factory and The Beehive II. Activity and Rotation in Praesepe and the Hyades
• The Caltech-NRAO Stripe 82 Survey (CNSS) Paper I: The Pilot Radio Transient Survey In 50 deg${}^2$
• Ultra-Wideband Detection of 22 Coherent Radio Bursts on M Dwarfs
• The XMM-Newton serendipitous ultraviolet source survey catalogue
• VAST: An ASKAP Survey for Variables and Slow Transients
• SubmilliJansky Transients in Archival Radio Observations
• An empirical template library of stellar spectra for a wide range of spectral classes, luminosity classes, and metallicities using SDSS BOSS spectra
• SPECULOOS -- Ultracool Dwarf Transit Survey: Target List and Strategy
• Quiescent Radio Emission from Southern Late-type M Dwarfs and a Spectacular Radio Flare from the M8 Dwarf DENIS 1048-3956
• The population of M dwarfs observed at low radio frequencies
• The χFactor: Determining the Strength of Activity in Low Mass Dwarfs
• A Flare-Type IV Burst Event from Proxima Centauri and Implications for Space Weather
• A VLA search for 5 GHz radio transients and variables at low Galactic latitudes
• K2 Ultracool Dwarfs Survey. III. White Light Flares are Ubiquitous in M6-L0 Dwarfs
• A 22-year Southern Sky Survey for Transient and Variable Radio Sources using the Molonglo Observatory Synthesis Telescope
• The variability timescales and brightness temperatures of radio flares from stars to supermassive black holes
• LOFAR MSSS: Detection of a low-frequency radio transient in 400 hrs of monitoring of the North Celestial Pole
• The seven year Swift-XRT point source catalog (1SWXRT)
• A circular polarisation survey for radio stars with the Australian SKA Pathfinder
• ASKAP Detection of Periodic and Elliptically Polarized Radio Pulses from UV Ceti
• K2 Ultracool Dwarfs Survey II: The White Light Flare Rate of Young Brown Dwarfs
• Rotational Modulation of M/L Dwarfs due to Magnetic Spots
• A search for long-timescale, low-frequency radio transients
• Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar Templates
• MKT J170456.2-482100: the first transient discovered by MeerKAT
• The 2018 outburst of BHXB H1743-322 as seen with MeerKAT
• Discovery of a Meter-Wavelength Radio Transient in the SWIRE Deep Field: 1046+59
• Discovery of ASKAP J173608.2-321635 as a Highly-Polarized Transient Point Source with the Australian SKA Pathfinder
• 21 new long-term variables in the GX 339-4 field: two years of MeerKAT monitoring
• CHILES VERDES: Radio variability at an unprecedented depth and cadence in the COSMOS field
• An insight into the extragalactic transient and variable microJy radio sky across multiple decades
• Detection of a Low-frequency Cosmic Radio Transient Using Two LWA Stations
• The detection of radio emission from known X-ray flaring star EXO 040830-7134.7
• A pilot survey for transients and variables with the Australian Square Kilometre Array Pathfinder
• The Solar Neighborhood XXV: Discovery of New Proper Motion Stars with 0.40 "/yr > mu > 0.18 "/yr between Declinations -47 degrees and 00 degrees

Cited by in corpus (9)

• Fine structures of radio bursts from flare star AD Leo with FAST observations
• Fast optical flares from M dwarfs detected by a one-second-cadence survey with Tomo-e Gozen
• Bursts from Space: MeerKAT - The first citizen science project dedicated to commensal radio transients
• The photometric periods of rapidly rotating field ultra-cool dwarfs
• Commensal Transient Searches in Eight Short Gamma Ray Burst Fields
• Finding radio transients with anomaly detection and active learning based on volunteer classifications
• Mining the time axis with TRON. I. Millisecond pulsars in Omega Centauri, Terzan 5 and 47 Tucanae detected through MeerKAT interferometric imaging
• Searching for Radio Transients with Inverted Spectra in Epoch 1 of VLASS and VCSS, and Identification of a Sample of Candidate Relativistic Nuclear Transients
• New Metrics for Identifying Variables and Transients in Large Astronomical Surveys