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"8293 results found.
- LIGO/Virgo G268556: iPTF Optical Transient Candidates
- Swift Trigger 730874 is not astrophysical
- LIGO/Virgo G268556/GW170104: Asiago Observations
- LIGO/Virgo G268556: Updated sky map from gravitational-wave data
- Swift Trigger 730513 is not an astrophysical event
- LIGO/Virgo G268556: ANTARES search
- LIGO/Virgo G268556: Fermi GBM Observations
- LIGO/Virgo G268556: Identification of a GW CBC Candidate
- Konus-Wind observation of GRB 170101A
- GRB 170101A: Swift-BAT refined analysis
- GRB161219B - Anticipated hyperluminal evidence
- GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
- GRB 161220A: Swift detection of a burst
- GRB 161219B: Swift detection of a burst with an optical afterglow
- GRB 161218A: CALET Gamma-Ray Burst Monitor detection
- GRB 161218A: Swift-BAT refined analysis
- Swift Trigger 727422 is not an astrophysical event.
- GRB 161217A: Swift detection of a burst
- IceCube-161210: Konus-Wind upper limits
- IceCube-161210: CALET Gamma-Ray Burst Monitor upper limits
- GRB 161214A: fading optical afterglow candidate with the LT
- HAWC follow-up on IceCube-161210
- INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161210
- IceCube-161210: IceCube observation of a high-energy neutrino candidate event
- GRB 161129A: NOT optical observations and candidate host galaxy
- GRB 161202A: Swift detection of a burst
- GRB 161129A: Swift detection of a burst
- GRB 161123A: Tiled Swift observations
- Swift Trigger 723124 is probably not a GRB
- Swift Trigger 722681 is probably not a GRB
- GRB 161117B: Swift detection of a burst
- GRB 161117A: Swift detection of a burst with an optical counterpart
- GRB 161113A: Swift detection of a burst
- IceCube-161103: CALET Gamma-Ray Burst Monitor upper limits
- GRB 161106A: CALET Gamma-Ray Burst Monitor detection
- GRB 161109A: Tiled Swift observations
- GRB 161108A: TAROT Calern observatory optical observations
- GRB 161105A: TAROT La Silla observatory optical observations
- GRB 161108A: RATIR Afterglow Confirmation
- GRB 161108A: NOT candidate afterglow
- GRB 161108A: Swift detection of a burst
- GRB 161103A: an ultra-long GRB detected by Konus-Wind
- IceCube-161103: Konus-Wind upper limits
- GRB 161104A: Gemini South optical observations
- Search for counterpart to IceCube-161103A with ANTARES
- GRB 161105A: Swift detection of a burst
- GRB 161104A: Swift detection of a short burst
- INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161103
- HAWC follow up of IceCube-161103
- IceCube-161103: IceCube observation of a very-high-energy neutrino
- GRB 161023A: Zadko observatory - Gingin optical observations
- GRB 161023A: Swift ToO observations
- Swift Trigger 718919 is not an astrophysical event.
- GRB 161022A: Fermi GBM observation
- GRB 161015A: further Swift-XRT follow-up observations
- GRB 161017A: Swift detection of a burst with a bright optical afterglow
- GRB 161015A: Tiled Swift observations
- GRB161014A: optical afterglow candidate with the LCOGT-FTS
- GRB 161014A: MITSuME-Akeno optical observation
- GRB 161011A: TSHAO afterglow candidate
- GRB 161011A: Swift detection of a burst
- GRB 161010A: Swift ToO observations
- GRB 161007A: AbAO optical observations
- GRB 161007A: Swift detection of a burst
- GRB 150302A: late-time imaging and optical afterglow confirmation
- GRB 161004B: Swift detection of a burst
- GRB 161004A: TSHAO optical observations
- GRB 161004A: Swift detection of a burst with a possible optical counterpart
- GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
- GRB 161001A: GROND afterglow candidate
- GRB 161001A: X-shooter spectroscopy, candidate host galaxy and redshift
- GRB 161001A: Swift detection of a burst
- GRB 160927A: RTT150 optical afterglow candidate
- GRB 160927A: Swift detection of a short hard burst
- GRB 160925A / Fermi 496473540: MASTER OT observations
- GRB 160925A: Swift ToO observations
- GRB 160917A: Mondy afterglow confirmation
- GRB 160917A: Swift/UVOT Detection
- GRB 160917A: Swift detection of a burst
- GRB 160912A, Swift-BAT refined analysis
- GRB 160912A: Swift detection of a burst
- GRB 160910A: Tiled Swift observations
- GRB 160905A: Swift detection of a burst with an optical counterpart
- Search for counterpart to IceCube-160814A with ANTARES
- GRB 160829A: Swift ToO observations
- Swift Trigger 710022 is very likely noise
- GRB 160826A: Swift-BAT refined analysis
- GRB 160826A: Swift detection of a burst
- GRB 160825A: Swift ToO observations
- GRB 160824A: Swift detection of a burst
- GRB 160821B: GTC follow-up observation
- GRB 160821B: WHT afterglow confirmation and redshift of candidate host
- GRB 160821B: Swift-BAT refined analysis
- GRB 160821B: NOT optical afterglow candidate
- GRB 160821B: Swift detection of a short burst
- INTEGRAL/SPI-ACS observation of IceCube HESE 128340 58537957
- GRB 160816A: RATIR Optical and NIR Afterglow Confirmation
- GRB 160816A: confirmed fading with the LT
- Fermi GBM Observations of IceCube-160806A
- GRB 160816A: RATIR Optical and NIR Observations