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"19358 results found.
- GRB 061121 declared "Burst of Interest" by Swift team
- Konus-Wind and Konus-A observations of GRB 061121
- Swift-BAT trigger 239987 is not a GRB
- GRB 061121: Swift/UVOT Observations
- GRB 061121: Swift-XRT Team Refined Analysis
- GRB 061121, Swift-BAT refined analysis
- GRB061121, optical observation
- GRB 061121: Faulkes Telescope North Optical Observation
- GRB 061121: ROTSE-III Confirmation of Optical Counterpart
- GRB 061121: Swift detection of a bright burst with an optical counterpart
- GRB 060111B: Swift UVOT Refined Magnitudes
- Swift-BAT triggers 238544 and 238546 are not GRBs
- Swift TOO observations of GRB061110A
- Swift/UVOT Upper Limits for GRB061110b
- Swift/UVOT Upper Limits for GRB061110a
- GRB 061110B: Swift XRT refined analysis
- GRB 061110B, Swift-BAT refined analysis
- GRB061110B: Optical observations at Crni Vrh
- GRB 061110A: Swift XRT refined analysis
- GRB 061110B: Swift/XRT position
- GRB 061110B: Swift-UVOT Initial Observation
- GRB 061110A, Swift-BAT refined analysis
- GRB 061110B: TAROT Calern observatory optical observations
- GRB 061110B: Swift detection of a burst
- GRB 061110: ROTSE-III Optical Limits
- GRB 061110: Swift detection of a burst
- Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
- GRB 061109: TAROT Calern observatory optical observations
- GRB 061109: Swift detection of a possible burst
- GRB061028: MAGIC telescope GeV observation
- GRB 061027: TAROT La Silla observatory optical observations
- GRB 061028: Swift/XRT Astrometry Correction
- GRB 061102: Swift/UVOT Magnitude Upper Limits
- GRB 061102, XRT refined analysis
- Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
- GRB061102B: Super-LOTIS observations
- GRB 061028: Optical R passband observations
- GRB 061102B: Swift detection of a possible burst
- GRB 061102, Swift-BAT refined analysis
- GRB 061102: Swift detection of a burst
- GRB 061028: VLA Observation
- GRB 061004: Swift/XRT Astrometry Correction
- GRB 060801: Swift/XRT Astrometry Correction
- GRB 061028: MDM Observations
- GRB 061028: SARA upper limit
- GRB061028: XRT refined analysis
- GRB 061028: Swift/UVOT Observations
- GRB 061028, Swift-BAT refined analysis
- GRB 061028: TAROT Calern observatory optical observations
- GRB 061028: Swift detection of a burst
- GRB 061027, Swift refined analysis of a possible burst
- GRB 061027: Swift detection of a possible burst
- GRB061025: Swift XRT refined analysis
- GRB061025: Swift/UVOT observations
- GRB061025: Swift XRT position
- Swift XRT boresight update
- GRB 061021, Swift-BAT Lag analysis
- Konus-Wind observation of GRB 061021
- GRB 061021: Swift-XRT refined analysis
- GRB 061021: Swift/UVOT Observation
- GRB 061021, Swift-BAT refined analysis
- GRB 061021: Swift detection of a burst
- GRB 061019: Super-LOTIS upper limit
- GRB 061019: SARA upper limit
- GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
- GRB 061019: Swift/UVOT upper limit
- GRB061019: Swift XRT refined analysis
- GRB 061019, Swift-BAT refined analysis
- GRB 061019: TAROT La Silla observatory optical observations
- GRB061019: Swift/XRT position
- GRB 061019: Swift-BAT detection of a burst
- GRB 061006: astrometry-corrected XRT position
- Konus-Wind observation of GRB 061007
- GRB 060928: Confirmation of the X-ray afterglow detected by Swift
- GRB061007: Swift UVOT followup observations
- GRB 061007: Magellan Spectroscopy
- GRB 061007: Correction to GCN 5712
- GRB 061007: Swift-BAT refined analysis
- GRB 061007: Swift XRT refined analysis
- GRB 061006: Swift/UVOT optical observations
- Konus-Wind observation of the short hard GRB 061006
- GRB 061007 - Faulkes Telescope South Afterglow Confirmation
- GRB 061007: Swift detection of a burst with an optical counterpart
- GRB 061007: ROTSE-III Detection of Optical Counterpart
- GRB 061006: Swift-BAT refined analysis of the short-hard burst
- GRB 061006: Swift-XRT Team Refined Analysis
- GRB061006 (Swift 232585) might be a short-hard GRB
- GRB061006: Faulkes Telescope South Observations
- GRB 061006: Swift detection of a burst
- GRB061004: Swift/UVOT optical observations
- GRB 061004: Swift-XRT Team Refined Analysis
- GRB 061004, Swift BAT refined analysis
- GRB 061004: Swift detection of a burst
- IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
- GRB 060928: Swift observations
- IPN triangulation of GRB060928 (long, exceptionally bright)
- GRB061002: Swift UVOT followup observations
- GRB 061002: Swift-XRT Team Refined Analysis
- GRB 061002, Swift-BAT refined analysis
- GRB061002: MASTER-VWF-Kislovodsk observations