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"5386 results found.
- GRB 130131A: Swift-BAT refined analysis
- GRB 130102B: MAXI/GSC detection
- GRB121212A: NOT optical imaging
- GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 121212A: Swift-BAT refined analysis
- GRB 121123A: NOT optical observations
- IPN Triangulation of GRB 121118B (long/intense)
- GRB 121102A: Swift-XRT refined Analysis
- GRB 121031A: Prompt enhanced Swift-XRT position
- GRB 121024A: SMARTS optical/IR afterglow observations
- GRB 121027A: MASTER early prompt optical limit
- GRB 121011A: optical observations
- GRB 120921A: Fermi GBM detection of its 1000th GRB
- GRB 120909A: Swift detection of a burst
- GRB 120907A: NOT optical observations
- GRB 120830A: Further Swift Observations
- GRB 120811C: optical observations
- GRB120804A: Chandra observations and afterglow detection
- Swift Trigger 530581: GRB 120811A or a galactic transient
- GRB 120803A: optical upper limit
- GRB 120804A: MITSuME Okayama Optical upper limits
- GRB 120803B: MITSuME Okayama Optical upper limits
- GRB 120803A: MITSuME Okayama Optical upper limits
- GRB 120803B: MITSuME Akeno Optical upper limits
- GRB 120803B: FTN possible afterglow candidate
- Swift Trigger 528925 is probably a noise fluctuation
- GRB 120724A: optical observation in Maidanak observatory
- GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120724A: Swift-XRT refined Analysis
- GRB 120724A: FTN optical afterglow candidate
- GRB 120716A: Swift-XRT detection
- GRB 120716A: Optical decay from NOT
- GRB 120714B: GROND confirmation of fading afterglow
- GRB 120714B: Position Correction and Candidate Optical Afterglow
- GRB 120712A: Swift-BAT refined analysis
- GRB 120712A: Swift detection of a burst with optical afterglow
- Swift detection of GRB 120711B or a new Galactic transient
- GRB 120709A: Swift-XRT observations
- GRB 120703A: Fermi GBM detection
- GRB 120630A: NOT optical source within the XRT error circle
- Swift Trigger 525554 is probably not a GRB
- GRB 120624B: Fermi GBM detection
- Swift trigger 524642 / SwJ1910.2-0546
- IPN Triangulation of GRB 120617A (short/intense)
- GRB 120603A: Suzaku WAM observation of the prompt emission
- GRB 120521C redshift estimate
- Konus-Wind observation of GRB 120522A
- IPN triangulation of GRB 120522A (long/intense)
- GRB 120521C: MASTER optical limit
- GRB 120514A: GROND upper limits
- GRB 120510A: MAXI/GSC detection of a burst
- IPN Triangulation of GRB 120427A
- Swift detection of 4U 1630-47
- IPN Triangulation of bright GRB 120426A
- GRB 120422A: MITSuME Ishigakijima upper limit
- GRB 120422A: Swift detection of a burst
- GRB 120404A: optical observations in Mondy observatory
- GRB 120404A: MASTER OT observations
- GRB 120404A: MITSuME Ishigakijima Optical Observation
- GRB 120401A: GROND Detection of an optical/NIR afterglow candidate
- GRB 120403B: Fermi GBM Observation
- GRB 120404A: Faulkes Telescope North afterglow confirmation
- GRB 120403A: MASTER follow up observations
- GRB 120402A: MASTER follow up observations
- GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
- GRB 120326A: Cima Rest and Bassano Brescia
- GRB 120326A: HCT optical observations
- GRB 120401A: Prompt enhanced Swift-XRT position
- GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
- GRB 120326A: MITSuME Ishigakijima Optical Observation at 3 days afterthe burst
- GRB 120326A: CARMA 3mm detection
- GRB 120328A: MITSuME Ishigakijima Optical Upper Limits
- GRB 120326A: MITSuME Ishigakijima Optical Observation at 2 days afterthe burst
- GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
- Swift trigger 518853: MASTER-ICATE possible OT
- long/intense GRB 120328B: MASTER follow up observations
- GRB 120326A: Bassano Bresciano Observatory further optical observations
- GRB 120327A: MITSuME Ishigakijima Optical Observation
- GRB 120326A: MITSuME Ishigakijima Optical Observation
- GRB 120328A: Swift detection of a burst
- GRB 120326A: PAIRITEL NIR Observations
- GRB 120327A: CQUEAN grizY Observation
- GRB 120326A: LOAO R-band Observations
- GRB 120327A: X-shooter redshift
- GROND observations of GRB 120327A
- GRB 120327A: Liverpool Telescope Observations
- GRB 120326A: optical observation of GMG
- GRB 120326A: T17 optical observations
- GRB 120326A: CQUEAN grizY Observation
- GRB 120323A: MASTER follow up observations
- IPN Triangulation of GRB 120323A (short/very intense)
- GRB 120324A: CQUEAN rizY Observation
- GRB 120320A: MITSuME Okayama Optical upper limits
- GRB 120320A , optical observations
- GRB 120320A: MASTER optical observations
- GRB 120311B: Optical follow-up
- GRB 120311A: C88 optical limits
- GRB 120312A: MASTER-NET optical observations
- GRB 120311B: C88 optical limits
- GRB 120311B: MITSuME Okayama Optical upper limits