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"20955 results found.
- LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
- Trigger 657564 / GRB 151004A: Swift/UVOT Upper Limits
- Swift Trigger 657564: MASTER-NET early optical observations.
- LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
- GRB 151001A: RATIR Observations
- GRB 151001B: Swift/UVOT Upper Limits
- GRB 151001A: Swift/UVOT Detection
- GRB 151001B: MASTER-NET early optical observations.
- GRB 150925A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: LOFAR follow-up
- LIGO/Virgo G184098: ASKAP followup
- LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
- LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
- LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
- LIGO/Virgo G184098: transient search with VISTA
- ANTARES neutrino detection: Fermi GBM Observations
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: SkyMapper observations
- LIGO/Virgo G184098: TAROT network optical observations
- LIGO/Virgo G184098: La Silla - QUEST Followup
- LIGO/Virgo G184098: Swift follow-up observations
- LIGO/Virgo G184098: MWA Followup
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- LIGO/Virgo G184098: Observations from the TOROS collaboration
- LIGO/Virgo G184098: iPTF Optical Transient Candidates
- LIGO/Virgo G184098: VST-ESO PARANAL observations
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- Instructions for reporting follow-up observations related to LIGO/Virgo G184098
- LIGO/Virgo G184098: observations by MASTER
- LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
- LIGO/Virgo G184098: Swift follow-up observations
- GRB 150910A: AAO optical observations
- GRB150915A : IRSF NIR upper limits
- GRB 150915A: NOT observations of a brightening afterglow
- GRB 150915A: Swift UVOT upper limits
- GRB 150910A: Mt. Terskol observatory optical observations
- GRB 150910A: TSHAO optical observations
- GRB 150915A: GROND detection of an optical counterpart candidate
- GRB 150915A: MASTER-NET optical observations
- GRB 150910A: T100 observations
- GRB 150911A: GROND Upper Limits
- GRB 150910A: Continued RATIR Observations
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150912A: Swift-XRT and UVOT observations
- GRB 150910A: RATIR Observations
- GRB 150912A: MASTER-IAC optical observations
- GRB 150912A: Swift ToO observations
- GRB150910A: P60 Observations
- GRB150911A: P60 Observations
- GRB 150911A: Swift/UVOT Upper Limits
- GRB 150910A: AAO optical observations
- GRB 150910A: Chuguev observatory optical observations
- GRB 150910A: VLA Detection
- GRB 150910A: continued SAO RAS optical observations
- GRB150911A MITSuME Okayama Ks-band upper-limit
- GRB 150910A: TSHAO optical observations
- GRB 150910A: NOT observations of the afterglow
- GRB 150910A: MITSuME Okayama Ks-band Observation
- GRB 150910A: GROND observation of the afterglow
- GRB 150910A: SAO RAS optical photometry
- GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
- GRB 150910A: Nanshan optical observations
- GRB 150910A: LCOGT FTN afterglow observations
- GRB 150910A: KAIT Optical Afterglow Detection
- Short GRB 150906B: proximity to NGC 3313 galaxy group
- GRB150907A: Swift/UVOT observations
- GRB 150907B: MASTER-SAAO early optical observations
- GRB 150907B: GROND Upper Limits
- GRB 150907B: Swift-XRT observations
- GRB 150907A: Swift-XRT observations
- GRB 150907A: Tiled Swift observations
- GRB 150818A: TSHAO and SAO RAS optical observations
- GRB 150902A: Swift-XRT afterglow detection
- ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
- ANTARES neutrino detection: CAHA photometry & spectroscopy of the Swift source
- ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
- ANTARES neutrino detection and Swift/XRT counterpart: GMG observation
- GRB 150902A: Swift/UVOT Upper Limits
- GRB 150902A: Swift-XRT observations
- GRB 150831A: 9.8 GHz VLA upper limits
- GRB 150902A: MASTER-SAAO optical observations
- ANTARES neutrino detection and possible Swift X-ray counterpart
- GRB 150902A: Swift ToO observations
- GRB 150831B: Swift/UVOT Upper Limits
- GRB 150821A: Flattening in the UVOT light curve
- GRB 150831B: MASTER-IAC early optical observations
- GRB 150831A: GROND Upper Limits
- GRB 150831A: Swift/UVOT Upper Limits
- GRB 150831B: Swift-XRT observations
- GRB 150831B: Swift detection of a probable burst
- GRB 150818A: possible SN rise in light curve of Mondy observations
- GRB 150821A: LCOGT Siding Springs early observations
- GRB 150821A: LCOGT Sutherland observations
- GRB 150821A: GROND afterglow observations
- GRB 150821A: Swift/UVOT Detection
- GRB 150818A: continued Mondy optical observations
- GRB 150821A: VLT/X-shooter redshift
- Swift Trigger 652824: Is most likely a noise fluctuation in the direction of M31
- GRB 120729A: KAIT Optical Observations