LEIA deteted a bright outburst from the high mass X-ray binary LMC X-4. The detected source position by LEIA is R.A. = 83.18 deg, DEC = -66.36 deg with an uncertainty of 2.2 arcmin (radius, 90% C.L. statistical and systematic), which is 55 arcsec away from LMC X-4.
LMC X-4 was covered twice by LEIA on January 20, 2023, and it brightened by more than an order of magnitude within 2 hours, with its 0.5 - 4.0 keV count rate increasing from 0.067 to 0.680 counts per second. During the outburst phase, the X-ray spectra can be fitted by a powerlaw with a photon index of 2.3 +/- 0.1 modified by Galactic absorption, and its 0.5 - 4.0 keV flux was ~1.6e-9 erg/s/cm2. This flux is comparable to the brightest fluxes of the outbursts of LMC X-4 as recorded by MAXI from August 2009 to January 2023.
Follow-up observations are encouraged to investigate this bright outburst from LMC X-4 in detail.
The preliminary results have been posted at Astronomer's Telegram as ATel 15871. Click here for more EP/LEIA Astronomer's Telegrams.