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"3043 results found.
- Fermi GBM trigger 334123030 (110804165) is not a GRB
- GRB 110801A: optical observations in CrAO
- GRB 110801A: SAO RAS optical observations
- GRB 110801A: Swift-BAT refined analysis
- Swift/UVOT observations of GRB110801A
- GRB 110801A: Enhanced Swift-XRT position
- GRB 110801A: Swift detection of a burst with an optical counterpart
- Sw J1644+57 (GRB 110328A): Continued VLBA Observations
- INTEGRAL Weak trigger #6331: GRT Optical Observation
- AXP 4U 0142+61: Swift-BAT refined analysis
- GRB 110726A: Swift-BAT refined analysis
- IPN triangulation of GRB 110721A
- GRB 110715A: Swift-BAT refined analysis
- GRB 110715A: Swift detection of a bright burst with an optical counterpart
- GRB 110708A: Konkoly observations
- GRB 110709B: Preliminary Swift-BAT refined analysis
- GRB 110708A: Lick observations
- GRB 110708A: Swift/XRT afterglow candidate for the INTEGRAL burst
- SGR 1E 1841-045: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift-BAT refined analysis
- GRB 110530A: Swift-BAT refined analysis
- Swift J1644+57/GRB 110328A, Additional HST Observations
- GRB 110520A: WHT IR observations
- GRB 110520A - NOT optical observation
- GRB 110520A: MASTER-NET optical observations
- GRB 110503A: Swift-BAT refined analysis
- GRB 110422A: Update of Herschel FIR observation schedule
- GRB 110422A: THO optical observations
- GRB 110422A: Swift-BAT refined analysis
- GRB 110420B: Swift-BAT refined analysis
- GRB 110420A: Swift-XRT refined Analysis
- GRB110414A: MITSuME Ishigakijima Optical upper limits
- GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
- GRB 110411A: MASTER prompt and follow-up optical limits
- GRB 110411A, Swift-BAT refined analysis
- GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
- GRB 110328A / Swift J164449.3+573451: optical observations
- GRB 110328A / Swift J164449.3+573451: VLBA Observations
- GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
- GRB 110407A: Swift-BAT refined analysis
- GRB110328A/Swift J164449.3+573451: Fermi LAT Observations
- GRB 110402A: Swift detection of a burst
- GRB 110328A / Swift J164449.3+573451: Radio-optical/NIR Astrometry
- GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
- GRB 110328A / Swift J164449.3+573451: BAT refined analysis
- GRB 110328A / Swift J164449.3+573451: Konkoly observations
- GRB 110328A / Swift J164449.3+573451: EVLA Detection
- GRB 110328A / Swift J164449.3+573451: NOT optical observations.
- GRB 110328A / Swift J164449.3+573451: PTF Quiescent Optical Counterpart
- GRB 110328A: Swift detection of a burst
- GRB 110319B Swift-XRT afterglow confirmation
- GRB 110319A: Swift-BAT refined analysis
- GRB 110318A: Swift-BAT refined analysis
- GRB 110315A: Swift-BAT refined analysis
- GRB 110315A: Swift detection of a burst
- GRB 110312A: GROND Upper Limits
- GRB110305A: MITSuME Ishigakijima Optical upper limits
- Swift XRT and UVOT Observations of OT 110215
- GRB 110213B: MAXI/GSC detection of a probable GRB
- GRB 110212A, Swift-BAT refined analysis
- SGR-like outburst from the magnetar 1E 1841-04.5
- GRB 110206A: SMARTS optical/IR afterglow candidate observations
- GRB 110206A: TAROT La Silla observatory optical observations
- GRB 101112A: Maidanak and CrAO optical observations
- GRB 110128A: Afterglow detection from NOT
- IPN triangulation of GRB 110120A
- GRB 110106B: MASTER optical observations
- Short GRB 110106A: MASTER OT observations
- Konus-Wind observation of GRB 110102A
- Trigger 441015 / GRB 101225A: Further NOT optical observation
- GRB 101224A, Swift-BAT refined analysis
- GRB 101123A: Fermi GBM detection
- XRF101117A: MAXI/GSC detection of a short X-ray transient
- GRB 101112A: optical observations
- GRB 101030A: Swift detection of a burst
- Konus-Wind observation of GRB 101023A
- GRB 101024A: Swift-BAT refined analysis
- GRB 101023A: Swift-BAT refined analysis
- GRB 101008A: optical observations
- GRB 100924A: Fermi GBM observation
- GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
- GRB 100915A: Swift-BAT refined analysis
- GRB100906A: R band observations
- GRB 100901A: ISON-NM optical observations
- GRB100901A: MITSuME Okayama Optical Observation at 1 day after the burst
- GRB 100902A: MASTER Prompt Optical Observations
- GRB100901A: MITSuME Okayama Optical Observation
- GRB 100816A, Swift-BAT refined analysis
- GRB 100814A: CQUEAN r- and i-band Observation
- GRB 100814A: GROND Detection of the Optical/NIR Afterglow
- GRB 100805A: optical observation in CrAO
- Trigger 430975: Swift detection of a possible burst
- GRB 100725B: Swift-BAT refined analysis
- GRB 100725B: Enhanced Swift-XRT position
- GRB 100725B: Swift detection of a burst
- GRB 100719A: Swift-BAT refined analysis
- GRB 100719A: Swift detection of a burst
- Konus-Wind observation of GRB 100707A
- GRB 100628A: Swift-BAT refined analysis
- GRB 100625A: Swift detection of a short hard burst