GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
191 results found.
- AT2024adec: X-ray Upper Limits from EP-FXT Observation
- XMM-Newton observation of EP240426a
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
- GRB 231115A: XMM-Newton observation
- GRB 211106A: XMM-Newton monitoring campaign detections
- IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
- Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
- GRB 200415A: MASTER imspection and possible localisation
- Further Swift-XRT observations of Swift J0840.7-3516
- LIGO/Virgo S200115j: Further Swift-XRT sources
- GRB 191031D: XMM-Newton upper limit
- IceCube-190221A: Swift-XRT Follow-up Observations
- CORRECTED TARGET NAME: GRB 190114C: Planned XMM-Newton observation
- GRB 150114C#: Planned XMM-Newton observation
- IceCube-190104A: Swift-XRT observations
- Trigger 809217: Swift trigger on RS CVn Star HD 8357
- GW170817/GRB170817A: Preliminary results of Chandra monitoring
- LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
- LIGO/Virgo G299232/GW170825: serendipitous XMM-Newton slew observations
- LIGO/Virgo G298936/GW170823: serendipitous XMM-Newton slew observations
- IceCube-170922A: Swift-XRT observations
- LIGO/Virgo G297595: Swift-XRT sources
- GRB170714A: XMM observation of the afterglow
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Swift-XRT sources
- LIGO/Virgo G268556: Swift-XRT detection of ATLAS17aeu
- Trigger 706396: Swift detection of a short burst from PSR 1119-6127
- LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB151127A: Planned XMM-Newton observation
- LIGO/Virgo G184098: Swift follow-up observations
- GRB 150818A: Planned XMM-Newton observation
- Trigger 649113: Swift detection of SGR 1E 1841-045
- Trigger 639199: Swift detection of IGRJ16418-4532
- Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
- Swift J0045.2+4151: analysis of XMM-Newton archival data
- Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
- BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
- Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
- GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
- GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
- The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
- Swift detection of the variable star SZ Psc
- Swift detection of UX Ari
- Swift detection of a bright X-ray source in M31
- Swift trigger 599860 probably not real
- Swift Trigger 596958 is probably the flare star: DG CVn
- GRB 131202A : XMM-Newton planned observation
- GRB 130821A: Swift-XRT observation
- GRB 130603B: First epoch of XMM-Newton observations
- Planned XMM-Newton and IRAM observation of GRB 121011A
- GRB 120804A: Late-time Chandra observation
- XMM observations of the short GRB120804A
- Trigger 530588: Swift detection of XMM J174457-2850.3
- GRB120711A: Planned XMM-Newton observation
- Swift triggers (#524542) on a Galactic source
- XMM-Newton observation of the short GRB 111020A
- GRB 111209A: GROND Afterglow observations
- GRB111209A : planned XMM-Newton observation
- GRB 111020A: Planned XMM-Newton observation
- SGR J1834.9-0846: A Neutron Star in W41?
- GRB 110807A: Swift detection of a burst or a posible new SGR
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- GRB 100909A: Planned XMM-Newton observation
- GRB 100614 : XMM-Newton observation
- Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
- Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
- GRB 090618: planned XMM-Newton observation
- Trigger 330353: Swift detection of a Galactic short soft burst
- SGR 0501+4516: preliminary results of the Suzaku ToO observation
- SGR 0501+4516: preliminary results of the first XMM-Newton observation
- SGR 0501+4516: XMM-Newton monitoring schedule
- GRB 080723B: GROND upper limits
- GRB 080723B: XMM-Newton observation
- GRB 080723B : Planned XMM-Newton observation
- Reactivation of SGR 1627-41
- GRB 080120 : Planned XMM-Newton observation
- GRB 071017 - Swift XRT observations
- GRB 070411 : Planned XMM-Newton observation
- GRB 061121 declared "Burst of Interest" by Swift team
- GRB 061121 : Planned XMM-Newton observation
- GRB060729: analysis of XMM-Newton observation
- GRB 060729 : Planned XMM-Newton observation
- GRB 060602B: XMM-Newton Survey Source
- XMM-Newton observation of GRB060510b
- GRB 060510B : Planned XMM-Newton observation
- INTEGRAL and XMM ToO observations of SGR1900+14
- GRB060218: analysis of the XMM-Newton observation
- GRB051016: analysis of the XMM-Newton observation
- GRB050925: analysis of the XMM-Newton observation
- GRB/SGR 050925: XMM-Newton ToO observation
- GRB051016 XMM-Newton observation
- GRB051016: Planned XMM-Newton observation
- GRB050820B: analysis of the XMM-Newton observation
- GRB050820B XMM-Newton observation
- GRB050820B: Planned XMM-Newton observation
- GRB 050730 XMM-Newton observation
- GRB 050730 : Planned XMM-Newton observation