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"44270 results found.
- GRB 111123A: optical upper limit in CrAO: correction to the GCN circ. 12613
- GRB 111204A: Enhanced Swift-XRT position
- GRB 111123A: optical upper limit in CrAO
- GRB 111204A: Swift detection of a burst
- GRB 111201A: Confirmation of the X-ray afterglow
- GRB 111201A: Swift/UVOT Upper Limits
- GRB111201A: Swift-XRT observations
- GRB 111201A found in ground analysis of BAT data
- GRB 111121A: Suzaku WAM observation of the prompt emission
- GRB 111129A: Swift/UVOT Detection
- GRB 111129A, GROND afterglow observations
- GRB 111129A: Swift-XRT refined Analysis
- GRB 111126A Circular #12599 erratum
- GRB 111129A: Swift-BAT refined analysis
- GRB 111129A: Enhanced Swift-XRT position
- GRB 111129A: Swift detection of a burst with an optical counterpart
- GRB 111126A found in ground analysis of BAT data
- GRB 111123A, Swift-BAT refined analysis
- GRB 111123A: Swift/UVOT Upper Limits
- GRB 111123A - NOT optical observations
- GRB 111123A, GROND observations
- GRB 111123A: correction to GCN 12593
- GRB 111123A: TNG NIR detection of the afterglow candidate
- GRB 111123A: Swift-XRT refined Analysis
- GRB 111123A: MITSuME Okayama Optical upper limits
- GRB 111123A: Enhanced Swift-XRT position
- GRB 111123A: GMG optical observation
- GRB 111117A: Refined Chandra Astrometry
- GRB 111123A: Swift detection of a burst
- GRB 111117A, the review of the sky area in plate archives
- Konus-Wind observation of GRB 111121A
- GRB 111121A: Swift/UVOT Upper Limits
- GRB 111121A: Magellan/Megacam observations
- GRB 111121A: Swift-XRT refined Analysis
- GRB 111121A: Swift-BAT refined analysis
- GRB 111117A: Chandra detection of the afterglow
- GRB 111121A: Enhanced Swift-XRT position
- GRB 111121A: Swift detection of a short hard burst
- GRB 111117A: Gemini Afterglow Limits
- GRB 111117A: optical upper limit in CrAO
- GRB 111117A: Fermi GBM observation
- GRB 111117A: further NOT observations
- GRB 111117A: EVLA observations
- GRB 111117A: TNG observations
- GRB 111117A: Swift/UVOT Upper Limits
- GRB 111117A: GROND observations
- GRB 111117A: Gemini host observation
- GRB111117A: Magellan IMACS observations
- GRB 111117A: Swift-XRT refined Analysis
- GRB111107A: Further ATCA observations - no detection
- GRB 111117A: NOT observations
- GRB 111117A: Chandra ToO observation scheduled
- GRB 111117A: Swift-BAT refined analysis of a short hard burst
- GRB 111117A: GMG upper limit
- GRB 111117A: Swift detection of a short hard burst
- GRB111107A: ATCA observations - upper limit and a possible detection
- Konus-Wind observation of GRB 111113A
- IPN Triangulation of GRB 111113A (short/hard/intense)
- XRF 111111A/MAXI J0158-744: MAXI GSC refined analysis
- XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
- GRB 111109A: Swift-XRT refined Analysis
- GRB 111109A: Swift/UVOT Photometry
- GRB 111109A: Swift-BAT refined analysis
- GRB 111109A: Enhanced Swift-XRT position
- GRB 111109A: Swift-XRT observations
- GRB 111109A: Swift detection of a burst
- GRB 111103B: optical upper limit of CrAO
- GRB 111103B: optical upper limit of Mt. Terskol observatory
- GRB 111107A: Fermi GBM observation
- Continued Skynet observations of GRB111107A
- GRB 111107A: Swift-XRT refined Analysis
- GRB 111107A: VLT/X-shooter spectroscopy
- GRB 111107A: APEX submm observation
- GRB 111107A: Swift/UVOT Afterglow Analysis
- GRB 111107A: Swift-BAT refined analysis
- GRB 111107A: Enhanced Swift-XRT position
- GRB 111107A: Gemini-South Redshift
- GRB 111107A: GROND observations
- Skynet observations of GRB 111107A
- GRB 111107A: Swift detection of a burst with an optical counterpart
- GRB 111103B: MITSuME Akeno Optical upper limits
- Konus-Wind observation of GRB 111103B
- GRB 111103B : WIYN 3.5m NIR observations
- GRB 111103B: Swift-XRT refined Analysis
- GRB 111103A: Fermi GBM observation
- GRB111103B Swift/UVOT Upper Limits
- GRB 111103B: optical observations from TAU, Ka-Dar
- Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
- GRB 111103B: Enhanced Swift-XRT position
- GRB 111103B: Swift-BAT refined analysis
- GRB 111103A: Swift-BAT refined analysis
- Trigger 506913: Swift detection of Swift J1922.7-1716 and its optical counterpart
- GRB 111022B: MASTER OT observations
- GRB 111103B: optical observations
- GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
- GRB 111103A: Swift detection of a burst
- Swift-BAT trigger 506884 is not a GRB
- GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
- GRB 111029A: SAO RAS optical limits
- GRB 111029A: Super-LOTIS early limits