MKT J170456.2-482100: the first transient discovered by MeerKAT

Abstract

We report the discovery of the first transient with MeerKAT, MKT J170456.2$-$482100, discovered in ThunderKAT images of the low mass X-ray binary GX339$-$4. MKT J170456.2$-$482100 is variable in the radio, reaching a maximum flux density of $0.71\pm 0.11\mathrm{mJy}$ on 2019 Oct 12, and is undetected in 15 out of 48 ThunderKAT epochs. MKT J170456.2$-$482100 is coincident with the chromospherically active K-type sub-giant TYC 8332-2529-1, and $\sim 18\mathrm{years}$ of archival optical photometry of the star shows that it varies with a period of $21.25\pm 0.04\mathrm{days}$. The shape and phase of the optical light curve changes over time, and we detect both X-ray and UV emission at the position of MKT J170456.2$-$482100, which may indicate that TYC 8332-2529-1 has large star spots. Spectroscopic analysis shows that TYC 8332-2529-1 is in a binary, and has a line-of-sight radial velocity amplitude of $43\mathrm{km}{\mathrm{s}}^{-1}$. We also observe a spectral feature in anti-phase with the K-type sub-giant, with a line-of-sight radial velocity amplitude of $\sim 12\pm 10\mathrm{km}{\mathrm{s}}^{-1}$, whose origins cannot currently be explained. Further observations and investigation are required to determine the nature of the MKT J170456.2$-$482100 system.

16 pages, 12 figures, 7 tables

References in corpus (27)

• The Gaia mission
• Astrophysics Source Code Library
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• PSRCHIVE and PSRFITS An Open Approach to Radio Pulsar Data Storage and Analysis
• Improving PARSEC models for very low mass stars
• A Radio Counterpart to a Neutron Star Merger
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• Science with ASKAP - the Australian Square Kilometre Array Pathfinder
• Pulsar Nulling and Mode Changing
• A radio pulsing white dwarf binary star
• Radio interferometric gain calibration as a complex optimization problem
• Fundamental parameters and infrared excesses of Tycho-Gaia stars
• Mass loss on the red giant branch: the value and metallicity dependence of Reimers' η in globular clusters
• SubmilliJansky Transients in Archival Radio Observations
• Polarimetric evidence of a white dwarf pulsar in the binary system AR Scorpii
• The variability timescales and brightness temperatures of radio flares from stars to supermassive black holes
• Ultra-high-time Resolution Observations of Radio Bursts on AD Leonis
• ASKAP Detection of Periodic and Elliptically Polarized Radio Pulses from UV Ceti
• Dwarf nova-type cataclysmic variable stars are significant radio emitters
• A search for long-timescale, low-frequency radio transients
• ThunderKAT: The MeerKAT Large Survey Project for Image-Plane Radio Transients
• The structure of accretion flows in nova-like cataclysmic variables: RW Sextantis and 1RXS J064434.5+334451
• Rapid Radio Flaring during an Anomalous Outburst of SS Cyg
• VLA multifrequency observations of RS CVn binaries
• A detailed radio study of the energetic, nearby and puzzling GRB 171010A
• Detection of a Low-frequency Cosmic Radio Transient Using Two LWA Stations
• Transient Emissions from Radio-Active Stars: Implications for Wide-Field Radio Surveys

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