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.
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"
18429 results found.
- 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: Swift-XRT refined Analysis
- GRB 111029A: PAIRITEL NIR Upper Limits
- GRB 111026A: Swift-BAT refined analysis
- GRB 111029A: Swift/UVOT Upper Limits
- GRB 111029A: KAIT optical limits
- GRB 111029A: Swift-BAT refined analysis
- GRB 111029A: Enhanced Swift-XRT position
- GRB 111029A: Faulkes Telescope North observations
- GRB 111029A: optical upper limit
- GRB 111029A: ROTSE-III Optical Limits
- GRB 111029A: Swift detection of a burst
- GRB 111026A: Swift detection of a burst
- GRB 111022B: EVLA observations - correction to GCN 12495
- GRB 111022B: EVLA observations
- GRB111022B: D50 optical limit
- GRB 111022A: MITSuME Akeno Optical upper limits
- GRB 111022B: Swift/UVOT upper limits
- GRB 111022A: Swift/UVOT Upper Limits
- GRB 111016A: optical upper limit
- GRB 111022B, Swift-BAT refined analysis
- GRB 111022B: Swift-XRT refined Analysis
- GRB 111022A: Swift-XRT refined Analysis
- GRB 111022B: NOT observations
- GRB 111022B: Enhanced Swift-XRT position
- GRB 111022A: Swift-BAT refined analysis
- GRB 111022B: MASTER-Net early limit
- GRB 111022A: Preliminary UVOT TDRSS Non-Detection
- GRB 111022A: MASTER-Net early limit
- GRB 111022B: Swift detection of a burst
- GRB 111022A: Swift detection of a burst
- GRB 111020A: Swift-XRT refined Analysis
- GRB 111020A: Swift/UVOT Upper Limits
- GRB 111020A: Swift-BAT refined analysis
- GRB 111020A: Enhanced Swift-XRT position
- GRB 111020A: BOOTES-3 Optical Upper Limit.
- GRB 111020A: Swift detection of a short burst
- GRB 111018A: Swift/UVOT Upper Limits
- GRB 111018A: Swift-BAT refined analysis
- GRB 111018A: Swift-XRT refined Analysis
- GRB 111018A: GROND Upper Limits
- GRB 111018A: Enhanced Swift-XRT position
- IPN Triangulation of GRB 111016B (long duration, intense)
- GRB 111018A: Swift detection of a burst
- GRB111016A: D50 optical limit
- GRB 111016A: Gemini Detection of the NIR Counterpart
- GRB 111016A: Swift/UVOT Detection of a Source
- GRB 111016A: Swift-BAT refined analysis
- GRB 111016A: P60 Afterglow Candidate
- GRB 111016A: Swift-XRT refined Analysis
- GRB 111016A: Enhanced Swift-XRT position
- GRB 111016A: Swift-XRT observations
- GRB 111016A: Swift detection of a burst
- GRB 110921A: optical observations
- EVLA 22 GHz Detection of GRB 111008A
- GRB 111008A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 111008A
- GRB 111008A: Swift-XRT refined Analysis
- GRB 111008A, GROND observations
- GRB 111008A: Enhanced Swift-XRT position
- GRB 111008A, Swift-BAT refined analysis,
- GRB 111008A: Swift detection of a burst
- GRB 111005A: Swift-BAT refined analysis
- GRB 111005A: Swift detection of a burst
- GRB 110905A / MAXI J1836-194: optical monitoring
- GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
- GRB 110928A: Swift/UVOT Upper Limits
- Trigger 504307: Swift detection of MAXI J1836-194
- GRB 110928A: Swift-XRT refined Analysis
- GRB 110928A: Enhanced Swift-XRT position
- GRB 110928A: P60 Observations
- GRB 110928A: Further PAIRITEL NIR Observations
- GRB 110928A: Swift-BAT refined analysis
- GRB 110928A: Swift-XRT observations
- GRB 110928A: Swift/UVOT finding chart observation
- GRB 110928A: ROTSE-III Optical Limits
- GRB 110928A: Swift detection of a burst
- Swift-BAT trigger 503926 is noise
- GRB 110924A: Swift detection of a possible burst
- GRB 110921A: Swift/UVOT Observations
- GRB 110921A: NOT observations
- GRB 110921A: Fermi GBM observation
- GRB 110921A: Swift-XRT refined Analysis
- GRB 110921A, Swift-BAT refined analysis
- GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
- GRB 110921A: Enhanced Swift-XRT position
- GRB 110918A: Swift-XRT refined Analysis
- GRB 110921A: MASTER-Net early limit
- GRB 110921A: Swift detection of a burst
- GRB 110915B : X-ray afterglow confirmation
- GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
- GRB 110918A: INT optical detection of Swift candidate afterglow
- GRB 110918A: Swift-XRT observations
- Swift detection of short bursts from PSR J1647-4552
- GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
- IPN triangulation of GRB 110918A (long duration, extremely intense)