XMM-Newton Target of Opportunity (ToO)

ToO Policies & Procedures

Targets of Opportunity (ToOs) are subject to the policies and procedures explained in the XMM-Newton Policies & Procedures Document which is available here.
Please, pay particular attention to Section 5.2.2 and especially Subsection 5.2.2.2, which makes reference to unanticipated ToO alerts explaining also the policy for the determination of proprietary periods of such observations.

"Discretionary Time” may be granted for programmes where a timely observation (outside of the normal announcement of opportunity cycle) is likely to result in a significant scientific impact.

ToO Alert

Investigators may notify the XMM-Newton SOC of a Target of Opportunity online. Simply complete the details on the ToO Notification Page.

Pending Anticipated ToOs

A list of anticipated ToO observations already accepted by the XMM-Newton Observing Time Allocation Committee (OTAC), which are currently not yet fulfilled, is available at this link.

Unanticipated ToO Details

The following list comprises approved and performed unanticipated ToOs.

The status of the data is denoted using the following acronyms:

The links from entries in this table are as follows:

This table is weekly updated, but there might be periods for which updates take slightly longer. Should you need to know details about a ToO/DPS observation, that are not given below (yet), please do not hesitate to contact the HelpDesk.

Rev Observation
Id
Target RA Dec Exp. Time
(ksec)
Data Status ODF Data
when available
PPS Data
when available
Proposer/
Comments
4835 0974792101 EP260302a 08:51:53.20 -65:59:02.0 35.0 ToO (TBD) ODF Data PPS Data (Dr. Y. Zhang)
4834 0974792001 AT2022dyt 10:00:08.00 +26:27:38.5 50.0 ToO (TBD) ODF Data PPS Data (Dr. S. Huang)
4827 0974791901 1A 0538-66 05:35:41.00 -66:51:53.6 33.5 ToO (TBD) ODF Data PPS Data (Dr. L. Ducci)
4824 0970191501 1ES 1927+654 19:27:19.50 +65:33:54.4 28.0 ToO (TBD) ODF Data PPS Data (Dr. M. Masterson)
4819 0970191401 1ES 1927+654 19:27:19.50 +65:33:54.4 27.4 ToO (15-Oct-2026) ODF Data PPS Data (Dr. M. Masterson)
4818 0970191301 1ES 1927+654 19:27:19.50 +65:33:54.4 28.0 ToO (08-Oct-2026) ODF Data PPS Data (Dr. M. Masterson)
4811 0974791701 AT2025aarm 04:32:12.40 -05:22:39.3 14.3 ToO (01-Oct-2026) ODF Data PPS Data (Dr. P. Baldini)
4806 0974791501 A0538-66 05:35:41.00 -66:51:53.6 33.2 ToO (17-Sep-2026) ODF Data PPS Data (Dr. P. Pradhan)
4797 0974791301 GRB251129A 14:57:18.90 +79:17:34.8 29.0 ToO (03-Sep-2026) ODF Data PPS Data (Dr. A. Martin-Carrillo)
4793 0974790301 Her X-1 16:57:49.80 +35:20:32.6 24.6 ToO (24-Aug-2026) ODF Data PPS Data (Dr. J. Wilms)
4792 0974790901 AT2025aarm 04:32:12.40 -05:22:39.3 25 ToO (24-Aug-2026) ODF Data PPS Data (Dr. P. Baldini)
4791 0974790701 GRB251129A 14:57:18.90 +79:17:34.8 29.9 ToO (24-Aug-2026) ODF Data PPS Data (Dr. A. Martin-Carrillo)
4786 0974790501 1A 1118-61 11:20:57.20 -61:55:00.1 20.0 ToO (13-Aug-2026) ODF Data PPS Data (Dr. C. Diez)
4785 0974790401 V1935 Cen 14:37:21.70 -58:47:43.4 57.4 ToO (13-Aug-2026) ODF Data PPS Data (Dr. M. Orio)
4783 0974790101 GRB251129A 14:57:18.90 +79:17:34.8 35.5 ToO (13-Aug-2026) ODF Data PPS Data (Dr. A. Martin-Carrillo)
4778 0970191201 1ES 1927+654 19:27:19.50 +65:33:54.4 29.5 ToO (05-Aug-2026) ODF Data PPS Data (Dr. M. Masterson)
4777 0970191101 1ES 1927+654 19:27:19.50 +65:33:54.4 27.9 ToO (05-Aug-2026) ODF Data PPS Data (Dr. M. Masterson)
4776 0970191001 1ES 1927+654 19:27:19.50 +65:33:54.4 29.4 ToO (05-Aug-2026) ODF Data PPS Data (Dr. M. Masterson)
4772 0973391201 AT2025clz 12:58:13.10 -15:46:36.8 38.0 ToO (26-Jul-2026) ODF Data PPS Data (Dr. Z. Lin)
4762 0973390701 IC 3599 12:37:41.20 +26:42:27.7 124.9 ToO (19-Jun-2026) ODF Data PPS Data (Dr. D. Grupe)
4760 0973391101 TRAPPIST-1 23:06:30.99 -05:02:41.5 22.5 ToO (22-Jun-2026) ODF Data PPS Data (Dr. W. Howard)
4754 0973390801 TRAPPIST-1 23:06:31.00 -05:02:41.5 17.0 ToO (01-Jun-2026) ODF Data PPS Data (Dr. W. Howard)
4741 0970190901 1ES 1927+654 19:27:19.50 +65:33:54.4 29.9 ToO (04-May-2026) ODF Data PPS Data (Dr. M. Masterson)
4739 0970190801 1ES 1927+654 19:27:19.50 +65:33:54.4 21.9 ToO (03-May-2026) ODF Data PPS Data (Dr. M. Masterson)
4737 0970190701 1ES 1927+654 19:27:19.50 +65:33:54.4 25.0 ToO (27-Apr-2026) ODF Data PPS Data (Dr. M. Masterson)
4736 0971191401 AT2024aehp 08:21:07.50 +28:44:22.2 40.0 ToO (23-Apr-2026) ODF Data PPS Data (Dr. Y. Yao)
4735 0973390601 4U1954+319 19:55:42.30 +32:05:49.2 53.0 ToO (23-Apr-2026) ODF Data PPS Data (Dr. C. Diez)
4730 0973390501 4U1822-37 18:25:46.80 -37:06:18.7 25.9 ToO (14-Apr-2026) ODF Data PPS Data (Dr. T. Di Salvo)
4730 0973390401 LEDA 251523 07:31:29.50 -74:10:31.4 40.1 ToO (14-Apr-2026) ODF Data PPS Data (Dr. J. Hu)
4729 0973390301 ASKAP J1745 17:45:08.90 -50:51:50.0 48.0 ToO (14-Apr-2026) ODF Data PPS Data (Dr. N. Rea)
4724 0973390201 EP250916a 17:52:57.30 -35:19:22.8 30.3 ToO (01-Apr-2026) ODF Data PPS Data (Dr. G. Illiano)
4720 0973390101 SAX J1808.4-3658 18:08:27.60 -36:58:44.4 34.0 ToO (22-Mar-2026) ODF Data PPS Data (Dr. S. Bhattacharya)
4711 0971191201 EP250630b 05:07:37.50 -69:24:11.1 50.0 ToO (Public) ODF Data PPS Data (Dr. C. Maitra)
4709 0971191301 NGC5907 ULX1 15:15:58.60 +56:18:10.7 50.0 ToO (Public) ODF Data PPS Data (Dr. D. Walton)
4709 0964050101 GW250818k 15:51:54.20 +30:54:08.3 54.0 ToO (08-Sep-2026) ODF Data PPS Data (Dr. E. Troja)
4698 0971190601 4U 0114+65 01:18:02.70 +65:17:29.7 23.0 ToO (Public) ODF Data PPS Data (Dr. J.M. Torrejon)
4697 0970190601 1ES 1927+654 19:27:19.50 +65:33:54.4 23.0 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4691 0971190701 AT2025clz 12:58:13.10 -15:46:36.8 33.4 ToO (Public) ODF Data PPS Data (Dr. Z. Lin)
4691 0971190501 T CrB 15:59:30.20 +25:55:12.7 64.0 ToO (Public) ODF Data PPS Data (Dr. G. Luna)
4685 0970190501 1ES 1927+654 19:27:19.50 +65:33:54.4 26.9 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4684 0970190401 1ES 1927+654 19:27:19.50 +65:33:54.4 27.0 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4679 0971800101 NGC5907 ULX1 15:15:58.60 +56:18:10.1 90.0 ToO (11-Jul-2026) ODF Data PPS Data (Dr. D. Walton)
4671 0971190401 TRAPPIST-1 23:06:29.40 -05:02:29.0 26.8 ToO (Public) ODF Data PPS Data (Dr. W. Howard)
4669 0971190301 AT2023uqm 23:10:39.00 +34:54:11.2 29.9 ToO (Public) ODF Data PPS Data (Dr. S. Huang)
4667 0954191701 NEXUS 17:53:51.00 +65:11:57.1 33.6 DPS (Public) ODF Data PPS Data (Dr. X Zhao)
4661 0930591701 ESO 198-G24 02:38:19.72 -52:11:32.3 135.4 Sat. Engineering (public) ODF Data PPS Data (Replenishment)
4660 0930591301 ESO 198-G24 02:38:19.72 -52:11:32.3 135.4 Sat. Engineering (public) ODF Data PPS Data (Replenishment)
4656 0971190101 AT2022arb 10:24:10.30 -00:49:22.8 135.4 ToO (Public) ODF Data PPS Data (Dr. J. Chakraborty)
4655 0971190201 MAXI J1957+032 19:56:39.00 +03:26:42.7 49.0 ToO (Public) ODF Data PPS Data (Dr. A. Sanna)
4652 0970190201 1ES 1927+654 19:27:19.53 +65:33:54.3 23.7 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4651 0970190301 1ES 1927+654 19:27:19.53 +65:33:54.4 27.5 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4650 0970190101 1ES 1927+654 19:27:19.53 +65:33:54.4 27.4 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4640 0954191601 AT2025chm 07:40:59.03 +16:31:53.8 35.8 ToO (Public) ODF Data PPS Data (Dr. S. Huang)
4631 0954191501 BG CMi 07:31:29.01 +09:56:22.9 32.5 ToO (Public) ODF Data PPS Data (Dr. A. Shaw)
4621 0954191401 IGR J17511-3057 17:51:08.54 -30:57:41.7 37.2 ToO (Public) ODF Data PPS Data (Dr. G. Illiano)
4617 0954191301 1RXS J052832.5+283824 05:28:32.68 +28:38:37.7 36.8 ToO (Public) ODF Data PPS Data (Dr. N. Rea)
4603 0954191201 AT2024xuo 10:08:49.70 -67:02:50.6 10.0 ToO (Public) ODF Data PPS Data (Dr. H. Tranin)
4601 0954191001 AT 2018cqh 02:33:46.90 -01:01:28.5 39.0 ToO (Public) ODF Data PPS Data (Dr. J. Wang)
4599 0954190901 EP241021a 01:55:23.60 +05:56:22.1 57.0 ToO (Public) ODF Data PPS Data (Dr. R. Eyles-Ferris)
4599 0953010801 1ES 1927+654 19:27:19.50 +65:33:54.4 28.8 ToO (Public) ODF Data PPS Data (Dr. M. Masterson)
4590 0954190801 OGLE16aaa 01:07:20.90 -64:16:20.6 18.5 ToO (Public) ODF Data PPS Data (Dr. M. Guolo)
4586 0954190201 AT2024mvz 23:40:27.80 -07:00:51.8 42.1 ToO (Public) ODF Data PPS Data (Dr. S. Huang)
4583 0954190401 eRASSt_J032543-45124 03:25:43.20 -45:12:44.6 135.2 ToO (Public) ODF Data PPS Data (Dr. R. Arcodia)
4582 0954190601 AT2022upj 00:23:56.90 -14:25:23.1 51.7 ToO (Public) ODF Data PPS Data (Dr. Z. Lin)
4578 0954190501 EP240222a 11:32:06.20 +27:00:17.6 75.2 ToO (Public) ODF Data PPS Data (Dr. W. Zhang)
4577 0954190301 GRB20241105A 04:24:59.00 -49:45:09.4 45.9 ToO (Public) ODF Data PPS Data (Dr. E. Troja)
4577 0954190101 AT2023lli 22:57:39.50 +40:32:39.8 30.1 ToO (Public) ODF Data PPS Data (Dr. S. Huang)
4576 0953791201 PG1211+143 12:14:17.70 +14:03:13.3 31.19 ToO (Public) ODF Data PPS Data (Dr. J. Reeves)
4575 0953791101 PG1211+143 12:14:17.70 +14:03:13.3 17.0 ToO (Public) ODF Data PPS Data (Dr. J. Reeves)
4575 0953790101 PG1211+143 12:14:17.70 +14:03:13.3 84.2 ToO (Public) ODF Data PPS Data (Dr. J. Reeves)
4574 0953012101 AT 2024puz 17:31:20.60 +53:24:15.1 46.4 ToO (Public) ODF Data PPS Data (Dr. J. Somalwar)
4569 0953790501 Vela X-1 09:02:06.90 -40:33:16.9 43.5 ToO (Public) ODF Data PPS Data (Dr. C. Diez)
4568 0942561301 AT2023cvb 19:14:25.60 +41:40:09.2 40.0 ToO (Public) ODF Data PPS Data (Dr. D. Lin / PI: Dr Guolo)
4566 0953791001 mrk 509 20:44:09.74 -10:43:24.6 56.4 ToO (Public) ODF Data PPS Data (Dr. V. Braito)
4566 0953790901 mrk 509 20:44:09.74 -10:43:24.6 15.0 ToO (Public) ODF Data PPS Data (Dr. V. Braito)
4565 0953790801 mrk 509 20:44:09.74 -10:43:24.6 35.6 ToO (Public) ODF Data PPS Data (Dr. V. Braito)

For ToO data prior to revolution 4565, please refer to the ToO Archive Page