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"12318 results found.
- GRB 131018A: Swift detection of a burst
- GRB 131014A: GROND observations
- GRB 131014A: RATIR Optical/NIR Afterglow Confirmation
- GRB 131011A: Swift/UVOT Upper Limits
- GRB 131014A: Swift/UVOT Upper Limits
- Fermi403206457: Weihai optical upper limit
- Trigger 574266 is not a Swift detection of a known source
- GRB 130831A: Continued RATIR Optical and NIR Observations
- GRB 131004A: Skynet PROMPT/DSO-14 upper limits
- GRB 131004A: CARMA 93 GHz upper limit
- GRB 131004A: Swift/UVOT Detection
- GRB 131004A: RATIR Optical and NIR Upper Limits
- GRB 131002B: GROND upper limits
- GRB 131002B: Swift/UVOT Upper Limits
- GRB 131002A: Swift/UVOT Detection
- Swift J1242.9-3530, Swift-BAT refined analysis
- GRB 131001A: Swift UVOT and XRT Upper Limits
- GRB 131002B: Swift detection of a burst
- GRB 131002A: Swift detection of a burst
- GRB 130929A: Swift/UVOT Upper Limits
- GRB 130831A: Continued RATIR Optical and NIR Observations
- Fermi LAT Upper Limits on GRB 130925A
- GRB 130925A: Swift/UVOT Upper Limits
- GRB 130925A: optical upper limit
- GRB 130925A: Continued RATIR Optical and NIR Observations
- Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
- GRB 130925A: RATIR Optical and NIR Observations
- GRB 130925A: Historical non-detection from Rosat-HRI
- GRB 130925A: TAROT La Silla observatory optical observations
- GRB 130925A: MAXI/GSC detection
- GRB 130925A: Swift detection of a burst
- GRB 130831A: RATIR Confirmation of NIR/Optical Afterglow Flattening
- GRB 130912A: AAO optical upper limit
- Fermi Trigger 401326696: MASTER prompt optical observations
- GRB 130919A: Skynet PROMPT-CTIO optical upper limits
- GRB 130903A: Further Swift XRT observations.
- GRB 130912A: Swift/UVOT Upper Limits
- GRB 130912A: 5.8 GHz VLA upper limit
- GRB 130912A: RATIR Optical and NIR Upper Limits
- GRB 130907A: Continued RATIR Optical and NIR Observations
- GRB 130907A: MASTER refined analysis
- GRB 130912A: REM optical/NIR upper limits
- GRB 130912A: KAIT optical upper limit
- GRB 120419A: Swift XRT confirmation of the afterglow
- GRB 130907A: Continued RATIR Optical and NIR Observations
- GRB 130907A: RATIR Optical and NIR Observations
- GRB 130828A: Further Swift XRT observations
- GRB 130907A: INTEGRAL/SPI-ACS light curve
- GRB 130907A: Swift/UVOT Detection
- Swift follow-up results of the possible weak INTEGRAL GRB
- GRB 130903A: Swift/UVOT Upper Limits
- Swift follow-up of an INTEGRAL possible weak GRB
- GRB 130831A: RATIR Optical and NIR Upper Limits
- GRB 130903A: MASTER early optical limit
- GRB 130903A: Swift-XRT observations
- GRB 130903A: ISON-Kislovodsk optical Upper Limits
- GRB 130903A: GROND Upper Limits
- GRB 130831A: Swift/UVOT Observations
- GRB 130831A: VLA Observations
- GRB 130831B: Swift/UVOT Upper Limits
- GRB 130831A: CARMA mm upper limit
- GRB 130831B: GROND upper limits
- GRB 130831B: Swift detection of a burst
- GRB 130822A: optical upper limits
- GRB 130821A: Weihai optical upper limit
- GRB 130821A: Swift-XRT observation
- GRB 130822A: 5.8 GHz VLA upper limit
- GRB 130822A: Gemini Observations
- GRB 130822A: WHT ACAM observations
- GRB 130822A: Swift/UVOT Upper Limits
- GRB 130822A: Weihai optical upper limit
- GRB 130822A: Swift detection of a short burst
- GRB 130816A: Swift/UVOT Upper Limits
- GRB 130816B: Swift/UVOT Upper Limits
- GRB 130816B: Swift detection of a burst
- GRB 130816A: Swift detection of a burst
- GRB 130812A: Swift/UVOT Upper Limits
- GRB 130812A: GROND upper limits
- GRB 130812A: Swift detection of a burst
- GRB130807A: Swift/UVOT observations
- GRB 130806A: Swift/UVOT Upper Limits
- GRB 130807A: Swift detection of a GRB or Galactic transient
- GRB 130623A: GROND detection of the optical/NIR afterglow
- GRB 130806A: MITSuME Akeno Optical observation
- GRB 130806A: MITSuME Okayama upper limits
- GRB 130806A: Swift detection of a burst
- GRB 130803A: RATIR Optical and NIR Observations
- GRB 130803A: Swift/UVOT Upper Limits
- GRB 130803A: Faulkes Telescope South Observations
- GRB 130727A: Swift/UVOT Detection
- GRB 130725B: Swift/UVOT Observations
- GRB 130725A: Swift/UVOT Upper Limits
- GRB 130725A: MITSuME Ishigakijima Optical Observation
- Swift Trigger 563980 is GRB 130725A
- GRB 130702A in the Ep,i - Eiso plane
- GRB 130722A: Swift/UVOT Detection
- GRB 130722A: MITSuME Okayama upper limits
- GRB 130722A: Swift detection of a burst
- GRB 130716A: UVOT Upper Limits
- GRB 130626A: Retraction of possible X-ray afterglow