TY - JOUR
T1 - MKT J170456.2-482100: the first transient discovered by MeerKAT
AU - Driessen, Laura Nicole
AU - Mcdonald, Iain
AU - Buckley, D. A. H.
AU - Caleb, Manisha
AU - Kotze, E. J.
AU - Potter, S. B.
AU - Rajwade, Kaustubh
AU - Rowlinson, A.
AU - Stappers, Benjamin
AU - Tremou, E.
AU - Woudt, P. A.
AU - Fender, R. P.
AU - Armstrong, R.
AU - Groot, P.
AU - Heywood, I.
AU - Horesh, A.
AU - van der Horst, A. J.
AU - Koerding, E.
AU - McBride, V. A.
AU - Miller-Jones, J. C. A.
AU - Mooley, K. P.
AU - Wijers, R. A. M. J.
PY - 2020/1
Y1 - 2020/1
N2 - 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±0.11mJy on 2019 October 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 ∼18yr of archival optical photometry of the star shows that it varies with a period of 21.25±0.04d. 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 43kms−1. We also observe a spectral feature in antiphase with the K-type sub-giant, with a line-of-sight radial velocity amplitude of ∼12±10kms−1, whose origins cannot currently be explained. Further observations and investigation are required to determine the nature of the MKT J170456.2-482100 system.
AB - 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±0.11mJy on 2019 October 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 ∼18yr of archival optical photometry of the star shows that it varies with a period of 21.25±0.04d. 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 43kms−1. We also observe a spectral feature in antiphase with the K-type sub-giant, with a line-of-sight radial velocity amplitude of ∼12±10kms−1, whose origins cannot currently be explained. Further observations and investigation are required to determine the nature of the MKT J170456.2-482100 system.
KW - stars: activity
KW - Binaries: spectroscopic
KW - stars: flare
KW - stars: peculiar
UR - http://arxiv.org/abs/1911.07713
http://dx.doi.org/10.1093/mnras/stz3027
UR - http://www.mendeley.com/research/mkt-j1704562482100-first-transient-discovered-meerkat
U2 - 10.1093/mnras/stz3027
DO - 10.1093/mnras/stz3027
M3 - Article
SN - 0035-8711
VL - 491
SP - 560
EP - 575
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -