LEIA discovered an X-ray transient LXT 221227A

LEIA (Lobster Eye Imager for Astronomy), also known as EP-WXT Pathfinder, detected a new X-ray transient, named LXT 221227A, on December 27, 2022. The source position is R.A. = 147.454 deg, DEC = 4.677 deg (J2000), with an uncertainty of 2.2 arcmin (radius, 90% C.L. statistical and systematic). The source was detected at a significance of 5.9 with 14 net photons. Assuming an absorbed power-law model with a photon index of 2.0 and a Galactic absorption of 3.3x10^19 cm^-2, the flux in the 0.5-4.0 keV is 1.8x10^-11 erg/cm^2/s.


The preliminary image of LXT 221227A detected by EP-WXT Pathfinder LEIA in comparison with the previous observation 5 days ago.

No known X-ray sources were found around this position. This position was also covered in two previous observations of LEIA at 2022-12-19T20:33:20 and 2022-12-22T19:30:44. While no X-ray sources were detected within the error circle of LXT 221227A. The preliminary short-term light curve of LXT 221227A shows a possible trend of declining, though with a large uncertainty due to the small number of counts.

Follow-up observations are encouraged to identify this new transient.

The preliminary results have been posted at Astronomer's Telegram as ATel 15834. Click here for more EP/LEIA Astronomer's Telegrams.