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"11841 results found.
- GRB 090715A: ROTSE-III Optical Limits
- Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
- GRB090713 optical limit by "Pi of the Sky"
- GRB 090621B: MTM-500 optical observations
- GRB 090709A: deep optical observation with the 10.4m GTC
- GRB 090709A: WHT LIRIS observations
- Konus-Wind and Konus-RF observations of GRB 090709A
- GRB 090709A: Swift XRT Refined Analysis
- GRB 090709A: Swift-BAT refined analysis
- GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
- GRB 090709: ROTSE-III Optical Limits
- GRB 090709: Swift detection of a bright burst
- GRB 090708: ROTSE-III Optical Limits
- GRB 090708: Swift detection of a burst
- GRB 090704: a long GRB found in INTEGRAL off-line analysis
- GRB 090706: Fermi GBM detection
- XRF 090702: a long soft GRB localized with INTEGRAL
- Konus-Wind observation of GRB 090626
- GRB 090628: Swift detection of a burst
- Fermi LAT observations of GRB 090626
- GRB 090618: SARA Second Epoch Observations
- GRB 090625B: a long GRB localized by INTEGRAL
- GRB 090623: Fermi GBM detection
- GRB 090621B: P60 Observations
- GRB 090620: Fermi GBM detecion
- Konus-Wind and Konus-RF observations of GRB 090618
- GRB 090621B: Swift-XRT refined analysis
- GRB 090621B: RTT150 optical observations
- GRB 090621B: Optical Observations
- GRB 090621A: Swift-BAT refined analysis
- GRB 090618 15GHz radio detection
- GRB090618: Swift-XRT team refined analysis
- GRB 090618: Lick/KAST Spectroscopy
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- RXTE Discovery of Pulsations from SGR 0418+5729
- Konus-RF observation of SGR burst 090605A
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- GRB 090607: XRT Team Refined Analysis
- GRB 090607: Swift detection of a burst
- GRB 090528B: Suzaku WAM observation of the prompt emission
- GRB 090531B: ROTSE-III Optical Limits
- GRB 090530: break in light curve
- GRB090530: Swift XRT refined analysis
- Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
- GRB 090530: Swift detection of a burst with an optical counterpart
- GRB 090529: optical observations
- GRB 090529: Xinglong TNT optical observation
- GRB 090529: Swift detection of a burst
- GRB 090520D: Fermi GBM detection
- GRB 090520C: Fermi GBM detection
- GRB 090520B: Fermi GBM detection
- GRB 090522 : Fermi GBM detection
- GRB 090518 - NOT upper limit
- GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090516C: Fermi GBM detection
- GRB 090520 Swift-BAT detection of a burst in ground analysis
- GRB 090516: Fermi GBM observation
- GRB 090519: Swift detection of a burst
- GRB 090518: Swift-XRT refined analysis
- GRB 090518: Swift detection of a burst
- GRB 090516: Swift-BAT refined analysis
- GRB 090516: Swift XRT refined analysis
- GRB 090516: Swift detection of a burst
- GRB 090515: Swift-XRT refined analysis
- GRB 090515: WIYN NIR Upper Limit
- GRB 090515: ROTSE-III Optical Limits
- GRB 090515: Swift detection of a short burst
- GRB 090510: Fermi-LAT follow-up analysis
- Konus-Wind observation of GRB 090510
- GRB 090510: Swift XRT refined analysis
- Fermi LAT detection of GRB 090510
- GRB 090510: Swift detection of a short hard burst
- GRB 090418A: optical observation
- GRB 090509: Swift detection of a burst
- 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 090427: GROND observations
- Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
- GRB 090424: YNAO-GMG observations
- GRB 090429A: Swift-XRT refined analysis
- GRB 090429B: Swift XRT refined analysis
- Konus-Wind observation of very bright GRB 090427
- GRB 090426: GAO 150cm telescope Optical Observation
- GRB 090426: YNAO-GMG observations
- GRB 090429B: GROND Observations
- GRB 090429B: Super-LOTIS early observations
- GRB 090429B: Swift detection of a burst
- IPN triangulation of very bright GRB 090427
- GRB 090424: Continued R-band monitoring
- GRB 090426: Okayama MITSuME optical observation
- GRB 090426: Swift detection of a burst with an optical counterpart
- GRB 090424: THO optical observations
- GRB 090424 optical observations
- GRB 090424: Swift-XRT refined analysis
- GRB 090424: Fermi GBM Observation
- GRB 090423 limiting magnitudes
- GRB 090423: UKIRT K-band observations
- GRB 090423: P60 Observations
- GRB 090423: Swift detection of a burst