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"7293 results found.
- GRB 111117A: Chandra detection of the afterglow
- GRB 111121A: Swift detection of a short hard burst
- GRB 111117A: Gemini Afterglow Limits
- GRB 111117A: GROND observations
- GRB 111117A: Swift detection of a short hard burst
- GRB 111107A: GROND observations
- GRB 111107A: Swift detection of a burst with an optical counterpart
- Trigger 506913: Swift detection of Swift J1922.7-1716 and its optical counterpart
- GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
- GRB 111029A: Swift detection of a burst
- GRB 111022B: 10.4m GTC z'-band observations
- GRB 111022A: RIzY Observation
- GRB 111022A: Preliminary UVOT TDRSS Non-Detection
- GRB 111022B: Swift detection of a burst
- GRB 111020A: Swift detection of a short burst
- GRB 111018A: Swift detection of a burst
- GRB 111016A: Gemini Detection of the NIR Counterpart
- GRB 111016A: P60 Afterglow Candidate
- GRB 111016A: Swift detection of a burst
- EVLA 22 GHz Detection of GRB 111008A
- GRB 111008A: Gemini spectroscopic redshift
- GRB 111008A: Swift detection of a burst
- GRB 110928A: Swift/UVOT finding chart observation
- GRB 110924A: Swift detection of a possible burst
- GRB 110918A: submm observations from APEX
- GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
- GRB 110921A: MITSuME Akeno Optical Observation
- GRB 110921A : TNT optical counterpart candidate
- GRB 110921A: Swift detection of a burst
- GRB 110918A: Gemini-N redshift
- GRB 110918A: Afterglow Confirmation from PTF
- GRB 110918A: GROND detection of the afterglow candidate
- GRB 110918A: INT optical detection of Swift candidate afterglow
- Swift detection of short bursts from PSR J1647-4552
- GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
- GRB 110915B: Afterglow candidate from OSN
- GRB 110915B: XRT afterglow candidate
- GRB 110915A: Swift detection of a burst
- GRB 110905A: Potential BAT trigger on MAXI J1836-194
- GRB 110825A: GMG optical observation
- GRB 110825A: optical afterglow candidate
- Swift-BAT Trigger 501485 is noise
- GRB 110820A: Swift/UVOT Upper Limits
- GRB 110820A: Position udpate + 2nd epoch data
- GRB 110820A: Swift detection of a burst
- GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
- GRB 110818A: Swift detection of a burst
- SGR J1834.9-0846: A Neutron Star in W41?
- GRB 110808A: VLT/X-shooter spectroscopy
- GRB 110808A: Swift detection of a burst with optical counterpart
- GRB 110807A: Swift detection of a burst or a posible new SGR
- GRB 110801A: Swift detection of a burst with an optical counterpart
- GRB 110731A: FTN+FTS afterglow observations
- GRB 110731A: Swift detection of a burst with an optical counterpart
- GRB 110721A: Swift observations of afterglow candidate
- Swift detection of a SGR-like burst from the AXP 4U 0142+61
- GRB 110726A: Swift/UVOT Detection
- GRB 110726A: Liverpool Telescope observations
- GRB 110726A: Swift detection of a burst
- IPN triangulation of GRB 110721A
- GRB 110721A: Gemini-South spectroscopy of the potential optical counterpart
- GRB 110721A: potential counterpart candidate
- GRB 110719A: Swift detection of a burst
- Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
- Swift J1822.3-1606
- GRB 110715A: Swift detection of a bright burst with an optical counterpart
- Swift trigger 457076 is not a GRB
- Swift Trigger 457076: a possible GRB
- GRB 110709B: GROND Detection of an Afterglow Candidate
- GRB 110709B: Swift detection of a burst
- GRB 110709A: Swift detection of a burst
- GRB 110708A: Swift/XRT afterglow candidate for the INTEGRAL burst
- Swift-BAT trigger 456532 is not astrophysical
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- GRB 110625A: Swift detection of a burst
- Swift J185003.2-005627: Swift detection of a burst from a new Galactic transient
- GRB 110618A: SMARTS optical observations
- GRB 110604A: final update on Swift-XRT observations
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- GRB 110530A: Swift detection of a burst with an optical afterglow
- GRB 110521A: Swift detection of a burst
- GRB 110520A: Swift detection of a burst
- GRB 110503A: TAROT Calern observatory optical observations
- GRB 110503A: Swift detection of a burst with a bright optical counterpart
- GRB 110422A: Swift detection of a burst
- GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
- GRB 110420B: Swift-XRT afterglow candidate retraction
- GRB 110420B, GROND observations
- GRB 110420B: Swift-XRT afterglow candidate
- GRB 110420A: Swift detection of a burst with optical counterpart
- GRB 110414A: Swift detection of a burst
- GRB 110411A: PAIRITEL NIR Upper Limits
- GRB 110411A: MASTER prompt and follow-up optical limits
- GRB 110411A : Xinglong TNT OT candidate
- GRB 110411A: Swift detection of a burst
- GRB 110407A : Lulin optical afterglow detection
- GRB 110407A: Swift detection of a burst
- GRB 110402A: Swift/UVOT detection of afterglow candidate
- GRB 110402A: Konkoly observations
- GRB 110402A: Swift detection of a burst