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"19533 results found.
- GRB 120922A: Swift detection of a burst
- GRB 120919A: Swift/UVOT Upper Limits
- GRB 120919A: Swift-XRT observations
- GRB 120918A: Swift-BAT refined analysis
- Swift trigger 534017 was not an astrophysical event
- Swift Trigger 534017 is probably not real.
- GRB 120918A: Swift detection of a burst
- IPN Triangulation of long GRB 120916A
- Swift Transient Swift J174510.8-262411: Swift-BAT refined analysis
- Swift Trigger 533836 is a new Galactic transient
- GRB 120913B: Fermi GBM observation
- GRB 120913B: Swift-BAT refined analysis
- GRB 120913A: Fermi GBM observation
- GRB 120913B: FRAM early follow up and detection
- GRB 120913A: Swift-BAT refined analysis
- Continued Skynet/PROMPT observations of GRB120913B
- GRB 120913B: TAROT La Silla observatory optical detection
- Skynet/PROMPT observations of GRB120913B
- GRB 120913B: Swift detection of a burst
- GRB 120913A: Swift detection of a burst
- GRB 120911A: optical upper limit CrAO
- GRB 120911A: optical upper limit ISON-NM
- GRB 120911A: Fermi GBM observation
- GRB 120911A: Fermi/LAT upper limit
- GRB 120911A: Swift/UVOT Upper Limits
- GRB 120911A: Swift-XRT refined Analysis
- GRB 120911A: Swift-BAT refined analysis
- GRB 120911A: Enhanced Swift-XRT position
- GRB 120911A: Swift-XRT observations
- GRB 120911A: ROTSE-III Optical Limits
- GRB 120911A: Swift detection of a burst
- GRB 120907A: SMA upper limits
- GRB 120908A and GRB 120909A : Fermi/LAT upper limit
- GRB 120908A: Swift Observations
- GRB 120909A: TAROT La Silla observatory optical observations
- GRB 120909A: Pi of the Sky upper limits
- GRB 120909A: Fermi GBM observation
- Konus-Wind observation of GRB 120909A
- GRB 120909A: Swift/UVOT Detection
- GRB 120909A: Swift-XRT refined Analysis
- GRB 120909A: Swift-BAT refined analysis
- GRB 120909A: Enhanced Swift-XRT position
- GRB 120909A: GROND detection of the afterglow
- Skynet/PROMPT Observations of GRB120909A
- GRB 120909A: Swift detection of a burst
- GRB 120907A: EVLA observations
- GRB 120907A: Swift/UVOT Detection
- GRB 120907A: Swift-XRT refined Analysis
- GRB 120907A: Enhanced Swift-XRT position
- GRB 120907A: Fermi GBM detection
- GRB 120907A: Swift-BAT refined analysis
- GRB 120907A: NOT optical observations
- GRB 120907A MASTER optical observations
- GRB 120907A: ROTSE-III Optical Limits
- GRB 120907A: Swift detection of a burst with optical counterpart
- XMM observations of the short GRB120804A
- GRB 120830A: Further Swift Observations
- GRB 120830A: catalog source at Uvot position
- GRB 120830A: Swift-XRT and UVOT observations
- IPN Triangulation of short GRB 120830A
- GRB 120830A: Fermi-LAT detection of a short burst
- GRB 120819A: Swift/UVOT Upper Limits
- GRB 120817A: Swift/UVOT Upper Limits
- GRB 120821A: Swift/XRT observations
- GRB 120821A: Swift/UVOT Upper Limits
- GRB 120821A: GROND upper limits
- GRB 120817B - PTF Observations
- GRB 120817A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 120817B: BAT location in ground analysis and refined analysis
- GRB 120819A: Bassano Bresciano Observatory optical observations
- GRB 120819A: Swift-BAT refined analysis
- GRB 120819A: GROND afterglow confirmation
- GRB 120819A: Swift-XRT refined Analysis
- GRB 120819A: Enhanced Swift-XRT position
- GRB 120819A: MASTER optical observations
- GRB 120819A: Swift detection of a burst
- GRB 120817B: Swift-XRT observations
- GRB 120816A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120815A: MASTER-ICATE observations
- IPN Triangulation of GRB 120816B (short/exceptionally intense)
- GRB 120817A: Swift-XRT refined Analysis
- IPN Triangulation of GRB 120817B (short/very intense)
- GRB 120817A: Swift-BAT refined analysis
- GRB 120816A: optical upper limit
- GRB 120817A: Enhanced Swift-XRT position
- GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120816A: Bassano Bresciano Observatory optical observations
- GRB 120816A: Swift-XRT refined Analysis
- GRB 120817A: Swift-XRT observations
- GRB 120817A: Swift detection of a burst
- GRB 120816A: Enhanced Swift-XRT position
- GRB 120816A: Swift-BAT refined analysis
- GRB 120816A: TAROT Calern observatory optical observations
- GRB 120816A: ROTSE-III Optical Limits
- GRB 120816A: Swift detection of a burst
- GRB 120815A: Swift-XRT refined Analysis
- GRB 120815A: Swift-BAT refined analysis
- GRB 120815A: Enhanced Swift-XRT position
- GRB 120815A: GROND afterglow candidate
- GRB 120815A: Swift-XRT observations