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"32508 results found.
- GRB 090529: Preliminary Swift/UVOT Upper Limit
- GRB 090529: Xinglong TNT optical observation
- GRB 090520B: Fermi GBM detection
- GRB 090518 - NOT upper limit
- GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090520: GROND upper limits
- GRB 090518: Fermi GBM detection
- GRB 090423: Fermi GBM T90 follow-up analysis results
- GRB 090516: Fermi GBM observation
- GRB 090519: Swift-XRT refined analysis
- GRB 090519: NOT refined analysis
- GRB 090519: VLT spectroscopic redshift
- GRB 090519: GROND observation
- GRB 090519: Swift/UVOT Upper Limits
- GRB 090519, Swift-BAT refined analysis
- GRB 090519: NOT afterglow candidate
- GRB 090518: Swift/UVOT Upper Limits
- GRB 090516: Observations from Stardome Observatory
- GRB090518: GROND upper limits
- GRB 090518: P60 Observations
- GRB 090518, Swift-BAT refined analysis
- GRB 090516, RIMOTS optical upper limits
- GRB090518 : Optical upper limit by MOA-II telescope
- GRB 090518: Swift-XRT refined analysis
- GRB 090515: Swift/BAT spectral lag results
- GRB 090516: Swift-BAT refined analysis
- GRB 090516: VLT spectrum (correction & update)
- GRB 090516: GROND OBSERVATIONS
- GRB 090516: VLT redshift
- GRB 090516 - Zadko Telescope observations
- GRB 090516: NOT optical observations
- GRB 090516: Swift XRT refined analysis
- GRB 090516: Swift/UVOT Observations
- GRB 090516: Faulkes Telescope South optical afterglow
- GRB 090515: Lick Upper Limits
- GRB 090515: ROVOR Upper Limit
- GRB 090515: MMT/MMIRS NIR Upper Limit
- GRB 090515: Swift/UVOT Observations
- GRB 090515: Swift-XRT refined analysis
- GRB 090509: Fermi GBM observation
- GRB 090515: Swift-BAT refined spectral analysis
- GRB 090515: Swift-BAT refined analysis
- GRB 090509 - Zadko Telescope observations
- GRB 090515: Gemini-N upper limit
- GRB 090515: WIYN NIR Upper Limit
- GRB 090515: Super-LOTIS Upper Limits
- GRB 090515: PAIRITEL Upper Limits
- GRB 090515: KAIT optical upper limits
- GRB 090515: ROTSE-III Optical Limits
- GRB 090510: Suzaku WAM observation of the prompt emission
- GRB 090510, Radio limits
- GRB090510: VLT/FORS2 spectroscopic redshift
- GRB 090510: GROND observations
- GRB 090510: Swift/UVOT host galaxy candidates
- GRB 090510: Fermi-LAT follow-up analysis
- GRB 090509, further Swift-BAT refined analysis
- GRB 090510: correction to GCN 9344
- Konus-Wind observation of GRB 090510
- AGILE detection of GRB 090510
- GRB 090510: UVOT refined analysis
- GRB 090510: Swift XRT refined analysis
- GRB 090510: correction to coordinates in GCN 9338
- GRB 090510: NOT afterglow confirmation
- GRB 090510: Swift-BAT refined analysis
- GRB 090510: Fermi GBM detection
- GRB 090509: Swift-BAT refined analysis
- GRB 090509, SMARTS optical/IR afterglow observations
- GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
- GRB 090408: optical upper limit
- GRB 090418A: optical observation
- GRB 090509: GROND further analysis and redshift limit
- GRB 090509: REM NIR afterglow
- GRB 090509: GROND afterglow candidate
- GRB 090323: optical observations
- GRB 090423: optical limit
- GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
- GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
- GRB 090424: optical observations
- GRB 090427: GROND observations
- GRB 090429A: ROVOR magnitude limit
- ICSP VLF observation of GRB090427 from two receivers
- ICSP VLF observation of GRB090424 from four receivers
- Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
- GRB 090428B: Suzaku WAM observation of the prompt emission
- GRB 090424, SMARTS optical/IR afterglow monitoring
- GRB 090426: optical observations
- GRB 090429B: Swift/UVOT Upper Limits
- GRB 090429A: Swift/UVOT Upper Limits
- GRB 090429B: Gemini-N further nIR observations
- GRB 090424: YNAO-GMG observations
- GRB 090429A: Swift-XRT refined analysis
- GRB 090429A: GROND upper limits
- GRB 090429B: Swift XRT refined analysis
- Konus-Wind observation of very bright GRB 090427
- GRB 090418A BVRcIc field calibration
- GRB 090426: GAO 150cm telescope Optical Observation
- GRB 090429B: RIMOTS optical upper limits
- GRB 090429B: Swift-BAT refined analysis
- GRB 090429A: Swift-BAT refined analysis
- GRB 090429A - Correction to XRT position