XRISM/Xtend is an X-ray telescope system that has a field of view (FOV) of 38.5 x 38.5 arcmin. The wide FOV allows us to observe serendipitous X-ray sources, including transients.
XRISM/Xtend Transient Search (XTS) is a science activity to search for and report X-ray transients serendipitously found in the Xtend FOV.
XTS on-ground process is performed every day as soon as possible after daily data downlink. When a transient source that has scientific value is discovered, XTS scientists report it via the Astronomer's Telegram (ATel) to encourage multi-wavelength follow-up observations.
In the general observer (GO) phase, XTS is executed with PI's allowance. Overview of XTS is found in
| ATel No. | Date | Title |
| 17243 | 2025-06-24 | XRISM/Xtend Transient Search (XTS) detected an X-ray brightening from XRISM J1235-3957 |
| 17242 | 2025-06-23 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from TWA 11 |
| 17232 | 2025-06-16 | XRISM/Xtend Transient Search (XTS) detected a flux increase of XRISM J1236-6432 |
| 17231 | 2025-06-16 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from XRISM J1235-6432 |
| 17214 | 2025-06-01 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from XRISM J0534-6600 in BSDL 2344 region of LMC |
| 17209 | 2025-05-28 | XRISM/Xtend Transient Search (XTS) detected multiple stellar flares from WOH S 423 |
| 17177 | 2025-05-09 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from an AGN candidate |
| 17145 | 2025-04-14 | XRISM/Xtend Transient Search (XTS) detected an outburst from a white dwarf candidate |
| 17144 | 2025-04-14 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from an eclipsing binary |
| 17136 | 2025-04-07 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a YSO |
| 17121 | 2025-03-31 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a spectroscopic binary |
| 17113 | 2025-03-27 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from XRISM J1733-2440 |
| 17092 | 2025-03-20 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare at the galactic center |
| 17071 | 2025-03-10 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare possibly from an M dwarf star |
| 17067 | 2025-03-07 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a YSO candidate |
| 17060 | 2025-03-02 | XRISM/Xtend Transient Search (XTS) detected an X-ray high state of 2SXPS J171724.0-371717 |
| 17049 | 2025-02-24 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from High Proper Motion Star UCAC4 661-042690 |
| 16990 | 2025-01-23 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from the flare star HD 120476 |
| 16962 | 2024-12-31 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from XRISM J0057+6021 |
| 16905 | 2024-11-12 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from EQ CVn |
| 16794 | 2024-08-30 | XRISM/Xtend Transient Search (XTS) detected a possible stellar flare from the Galactic center |
| 16779 | 2024-08-19 | XRISM/Xtend Transient Search (XTS) detected a possible stellar flare from 4XMM J114021.0-651852/1eRASS J114021.5-651851 |
| 16777 | 2024-08-16 | XRISM/Xtend Transient Search (XTS) reported the third detection of a prestellar flare from 2MASS J11414215-6521298 |
| 16775 | 2024-08-15 | XRISM/Xtend Transient Search (XTS) reported the second detection of a prestellar flare from 2MASS J11414215-6521298 |
| 16774 | 2024-08-15 | XRISM/Xtend Transient Search (XTS) detected a possible stellar flare from 2MASS J11414215-6521298 |
| 16773 | 2024-08-15 | XRISM/Xtend Transient Search (XTS) detected a possible stellar flare from 1RXS J113700.0-651617 |
| 16731 | 2024-07-23 | XRISM/Xtend Transient Search (XTS) detected the second X-ray flare from UCAC2 15735923 |
| 16728 | 2024-07-21 | XRISM/Xtend Transient Search (XTS) detected a possible stellar flare from UCAC2 15735923 |
| 16685 | 2024-07-03 | XRISM/Xtend Transient Search (XTS) detected the second X-ray flare from a BY Dra variable MS Ser |
| 16683 | 2024-07-02 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a BY Dra variable MS Ser |
| 16652 | 2024-06-14 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare possibly from a spectroscopic binary |
| 16632 | 2024-05-28 | XRISM/Xtend Transient Search (XTS) detected SN2024iss |
| 16607 | 2024-05-01 | XRISM/Xtend Transient Search (XTS) detected an X-ray outburst from a high-mass X-ray binary AX J1910.7+0917 |
| 16592 | 2024-04-17 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare possibly from a spectroscopic binary |
| 16561 | 2024-03-31 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare possibly from a YSO candidate |
| 16558 | 2024-03-28 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare possibly from 4XMM J190821.5+065854 |
| 16532 | 2024-03-15 | XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a plausible optical counterpart LP 593-21 |