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"
2724 results found.
- Fermi GRB190425.09 Global MASTER-Net observations report
- LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190408an: Liverpool Telescope follow-up imaging observations
- Swift GRB190422.96 Global MASTER-Net observations report
- Fermi GRB190422.67 Global MASTER-Net observations report
- LIGO/Virgo S190421ar Global MASTER-Net observations report
- LIGO/VIRGO S190421ar: IceCube Neutrino Search
- LIGO/Virgo S190408an: INTEGRAL follow-up observations
- Fermi GRB190420.98 Global MASTER-Net observations report
- LIGO/Virgo S190412m: SVOM/GWAC observations of the initial skymap
- Fermi GRB190419.41 Global MASTER-Net observations report
- GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
- GRB 190404C: MITSuME Akeno and Okayama optical upper limits
- GRB190404C: GROWTH-India discovery of optical counterpart
- GRB 140404B: MAXI/GSC detection
- GRB 190330A: MITSuME Akeno and Okayama optical upper limits
- GRB 190331A: Fermi GBM detection
- MAGIC follow-up of the X-ray flares of LS I +61�303 dete
- GRB 190324A: Swift/UVOT Observations
- GRB 190326A: Swift detection of a short burst
- GRB 190324A: Swift/UVOT afterglow candidate
- Swift detection of LS I +61 303
- Trigger 890732: Swift detection of MAXI J1631-479
- IceCube-190221A: MASTER Global Robotic Net optical observation
- Trigger 888312: Swift detection of 4U 1901+03
- GRB 190204A: Swift detection of a burst with a possible optical counterpart
- GRB 190202A: SAO RAS optical observations
- GRB 190129A: MAXI/GSC detection
- Swift Trigger 886157: MASTER optical observation
- IPN Triangulation of GRB 190117A (long)
- GRB 190114C: UKIRT JHK observation (CORRECTIONS)
- GRB 190114C: Continued UKIRT JHK observation
- GRB 190114C: UKIRT JHK observation
- GRB 190114C: REM optical/NIR detection
- GRB 190114B: Liverpool Telescope near-IR observations
- CORRECTED TARGET NAME: GRB 190114C: Planned XMM-Newton observation
- GRB 190114C: MASTER afterglow Detection
- IceCube-190104A: Swift-XRT observations
- GRB 190106A: GMG photometry in the 2nd night
- GRB 190106A: Swift detection of a burst with an optical counterpart
- GRB 181228A: Global MASTER Net OT detection
- GRB 181225A: KAIT Follow-Up Observations with Upper Limit
- Trigger 878548: Swift detection of AX 1631.9-4752
- Konus-Wind observation of GRB 181212A
- IPN Triangulation of GRB 181212A (long)
- MASTER: OTs detection during Fermi alert trigger 565936249 early observations
- GRB 181126B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 564897175)
- GRB 181203A: Swift detection of a burst
- Konus-Wind observation of GRB 181121A
- GRB 181125A: Swift detection of a burst
- GRB 181030A: MASTER Net OT detection
- GRB 181030A: SAO RAS optical observations
- IPN Triangulation of GRB 181028A (long)
- GRB 180728B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 554505003)
- GRB 181022A: Swift-XRT refined Analysis
- GRB 181020A: Swift/UVOT Detection
- GRB 181020A: Global MASTER Net OT observations
- GRB 181020A: VLT/X-shooter spectroscopy and redshift
- GRB 181020A: Swift detection of a burst with an optical counterpart
- GRB 181011A: Global MASTER Net optical inspection
- GRB 181011A: MAXI/GSC detection
- GRB180913A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 558557292)
- GRB 181008B: Global MASTER Net optical inspection
- GRB 180930A: Swift-XRT refined Analysis
- GRB 180930A: Swift detection of a burst
- GRB 180914B: OAJ multi-color follow-up
- IPN Triangulation of GRB 180914A (long)
- GRB 180914B: MASTER OT automatic dtection
- GRB 180914B: KAIT Optical Afterglow Candidate
- GRB 180828A: RATIR Optical and NIR Observations
- GRB 180828A: Swift-BAT refined analysis
- GRB 180828A: Swift-XRT refined Analysis
- GRB 180828A / Swift J1754.9-2548: Enhanced Swift-XRT position
- GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
- GRB 180821A: BOOTES-3/YA optical observations
- GRB 180809A: Swift-XRT afterglow detection
- GRB 180701A/MAXI J2119-045: CALET Gamma-Ray Burst Monitor data search
- GRB 180720B: MASTER Global Net OT observations
- GRB 180715B: AstroSat CZTI detection
- FRB 180714: MASTER optical inspection of the Fast Rado Burst Transient
- GRB 180721A: Swift detection of a burst
- GRB 180720C: LT observations
- GRB 180718A: MASTER optical observation
- GRB180715B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 553369644)
- GRB 180718A short GRB detected by IPN and found in ground analysis of BAT data
- Swift Trigger 848621 is not an astrophysical event
- IceCube-171106A: MASTER optical observation
- GRB 180709A: Optical limits
- GRB 180703A: Swift/UVOT Upper Limits
- GRB 180701A: MAXI/GSC detection
- GRB 180626C: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 551697835)
- Konus-Wind observation of GRB 180626B
- IPN Triangulation of GRB 180626B (short)
- GRB 180624A: Swift-BAT refined analysis
- GRB 180624A: MITSuME Okayama optical upper limits
- Konus-Wind observation of GRB 180618A (a short GRB with extended emission)
- GRB 180614A: MASTER observation
- Konus-Wind observation of GRB 180611A
- GRB 180602A: MITSuME Okayama optical upper limits
- IPN Triangulation of GRB 180526A (long)