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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"113 results found.
- GRBs 250702B/C/D/E / EP250702a: Swift/UVOT Upper Limits
- GRB 250521D: SVOM/GRM analysis suggests a possible “long” duration type I burst
- Fermi trigger No 769499303: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S250206dm: early X-ray upper limits from Einstein Probe WXT and preliminary results of FXT observations
- Fermi GRB 241209D: Global MASTER-Net observations report
- Fermi trigger No 754701230: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S241130n: Updated Sky localization
- Swift GRB 240805A: Global MASTER-Net observations report
- Swift Trigger 1232465: consistent with noise
- GRB 240414A: Swift/UVOT Detection
- Swift GRB240123.46: Global MASTER-Net observations report
- GRB 220611A: Swift/UVOT Upper Limits
- GRB 220306B: Swift/UVOT Upper Limits
- Fermi GRB 220222B: Global MASTER-Net observations report
- GRB 210930A: Swift/UVOT Upper Limits
- Fermi trigger No 652585475: Global MASTER-Net observations report
- GRB 210901A: Enhanced Swift-XRT position
- Fermi trigger No 649072251: Global MASTER-Net observations report
- Fermi trigger No 647624281: Global MASTER-Net observations report
- GRB 210323A: Swift/UVOT Upper Limits
- GRB 201104B: Swift-BAT refined analysis
- Fermi GRB 200909A: Global MASTER-Net observations report
- GRB 200803A: Fermi GBM detection
- Baksan Neutrino Observatory Alert 200601.42: Global MASTER-Net observations report
- Swift GRB200306.95: Global MASTER-Net observations report
- GRB 200215A: Swift/UVOT Upper Limits
- GRB 200122A: Swift-BAT refined analysis
- Fermi trigger No 594557071: Global MASTER-Net observations report
- GRB 191017B: Swift/UVOT Upper Limits
- LIGO/Virgo S190425z: COATLI Observations of Galaxies
- GRB 181002A: Swift/UVOT Upper Limits
- GRB 180504A: Swift/UVOT Upper Limits
- GRB 180425A: Swift/UVOT Upper Limits
- GRB 180418A: TAROT La Silla observatory early optical observations
- GRB 180404A: Swift/UVOT Detection
- Trigger 813449: Swift detection of large burst from XTE J1701-407
- GRB 171216A: Swift-BAT refined analysis
- GRB 170813A: Swift/UVOT Upper Limits
- GRB 170531B: Swift/UVOT Detection
- GRB170519A, Swift-UVOT Detection
- GRB 170510A: Fermi GBM observation
- GRB 160801A: Swift/UVOT Upper Limits
- Swift-BAT trigger 686845 was due to noise near a known source
- GRB 160408A: Swift-BAT refined analysis
- GRB 151229A: Swift/UVOT observations
- GRB 151210A: Swift/UVOT Upper Limits
- Swift trigger 637807 is probably not an astrophysical source
- GRB 150213B: Swift/UVOT Detection
- GRB 140810A: Fermi GBM observation
- GRB 140622A: An unusual short event, Swift-BAT refined analysis
- GRB 131030A: Swift/UVOT Detection
- GRB 130527A: Swift-BAT refined analysis
- Trigger 538084: Swift detection of XTE J1739-302
- GRB 120119A: Swift/UVOT Observations
- GRB 111204A: Swift/UVOT Upper Limits
- GRB 111022B: Swift/UVOT upper limits
- GRB 111008A, Swift-BAT refined analysis,
- Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
- Swift J185003.2-005627: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift-BAT refined analysis
- Swift/UVOT observations of GRB110210a.
- GRB 110128A: Swift/UVOT observations
- GRB 101011A: Swift-BAT refined analysis
- IBAS Alert n. 6057 is not due to a GRB
- GRB 100628A: Swift/UVOT Upper Limits
- Trigger 424161: Swift/BAT trigger on XTE J1946+274/GRO J1944+26
- GRB 100514A: Swift-BAT refined analysis
- Swift-BAT trigger 421695 is likely not astrophysical
- IBAS Alert 5992 is not a GRB, but XTE J1855-026
- GRB 100206A: Swift-BAT refined analysis
- Swift/UVOT refined analysis of GRB100117A
- Swift/BAT Detects an Outburst from XTE J1901+014
- Swift Trigger #382159 is due to XTE J1752-223
- Swift-BAT trigger 373691 is a galactic bulge transient
- GRB 091010: RXTE detection
- GRB 090727: Swift-BAT refined analysis
- GRB 090429A: Swift-BAT refined analysis
- GRB 090113: Swift-BAT refined analysis
- GRB 080805, Swift-BAT refined analysis
- Swift detection of XTE J1701-407
- Trigger 317205: Swift detection of an outburst from XTE J1701-407
- GRB 080607, Swift-BAT refined analysis
- GRB 080602, Swift-BAT refined analysis
- A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
- GRB 070731, Swift-BAT refined analysis
- Swift/UVOT observations of GRB070429B
- GRB 070318, Swift-BAT refined analysis
- GRB 070209, Swift-BAT refined analysis of the short hard burst
- GRB 061222A, Swift-BAT refined analysis
- GRB 060908, Swift-BAT refined analysis
- GRB 060807: Refined analysis of the Swift-BAT burst
- Konus-Wind observation of GRB 060614
- GRB 060312: Refined analysis of the Swift-BAT burst
- GRB 060223B: Swift-BAT refined analysis
- GRB 060223: Swift-BAT refined analysis
- GRB 060115: Refined analysis of the Swift-BAT burst
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
- SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
- IPN detection of continued activity from SGR1806-20