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"55 results found.
- GRB 250211A: SVOM trigger sb25021103 is not a GRB
- Fermi trigger No 736197684: Global MASTER-Net observations report
- Swift Trigger 1220736: detection of 4U 1543-62.
- Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
- Trigger 1062273: Swift detection of 4U 1700-377
- Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
- Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
- Swift trigger 1047857 is 4U 1700-377
- GRB 210421A: Swift/UVOT Upper Limits
- GECAM detection of a burst possibly from the X-ray burster 4U 0614+09 or GRB 210124A
- GRB 201103B: AGILE detection
- GRB 201029A: Swift-XRT refined Analysis
- LIGO/Virgo S191222n: Updated Sky Localization
- LIGO/Virgo S190718y Global MASTER-Net observations report
- Fermi trigger No 583567803 Global MASTER-Net observations report
- Trigger 888312: Swift detection of 4U 1901+03
- Swift trigger 831888: misidentification of 4U 1416-62
- Fermi GBM Detection of possible burst from AXP 4U 0142+61
- GRB 170113A: Swift/UVOT Observations
- Swift Trigger 718766 is not an astrophysical event.
- Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
- GRB 160409A found in Swift BAT ground analysis
- Swift detection of 4U 1850-03
- GRB 150301A: Fermi GBM observation
- Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
- Fermi GBM Observations of Magnetar 4U 0142+61
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- Trigger 631747: Swift detection of 4U 0614+09
- Swift detection of 4U 1700+24 (= V* V934 Her)
- Swift detection of 4U 1700+24 (= V934 Her)
- Swift detection of outburst from 4U 1700+24
- Swift trigger 609139 is probably 4U 1850-03
- GRB 130816A: Swift/UVOT Upper Limits
- Swift Trigger 558828 is not an interesting event
- Swift Trigger 557674 was due to an onboard position error
- Swift Trigger 530581: GRB 120811A or a galactic transient
- Swift detection of 4U 1630-47
- GRB 120311A: Swift/UVOT Upper Limits
- AXP 4U 1042+61: Mondy optical observations
- AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
- Swift detection of an SGR burst from AXP 4U 0142+61
- SGR J1834.9-0846: A Neutron Star in W41?
- AXP 4U 0142+61: Fermi GBM detection
- AXP 4U 0142+61: Swift-BAT refined analysis
- Swift detection of a SGR-like burst from the AXP 4U 0142+61
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- GRB 070628 Swift-UVOT Refined Analysis
- Retractions of previous Swift-BAT triggers
- Swift detection of an outburst from the 4U 1246-58 LMXB burster
- GRB060602A: Swift/UVOT upper limits
- IBAS GRB Alerts 1978-1980
- GRB040903 - A XRF?
- GRB030131: Candidate Optical Afterglow
- IPN detection of possible bursts from SGR1806-20
- GRB980326 X-ray Observations