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"28059 results found.
- GRB 200830A: BALROG localization (Fermi Trigger 620474063 / GRB 200830413)
- GRB 200826A
- GRB 200829A: Swift-XRT refined Analysis
- GRB 200829A: Enhanced Swift-XRT position
- GRB 200826A: Lowell Discovery Telescope observations of ZTF20abwysqy
- GRB 200829A: Swift/UVOT Detection
- GRB 200829A: TSHAO optical observations
- GRB 200829A: Swift detection of a burst with an optical afterglow
- GRB 200826A: Kitab optical observations
- Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
- GRB 200826A: further analysis of the Konus-Wind data and classification
- GRB 200826A: Swift-XRT afterglow detection
- GRB 200824A: Insight-HXMT/HE detection
- GRB 200826A: BALROG localization (Fermi Trigger 620108997 / GRB 200826187)
- Swift Trigger 992444 is due to detector noise
- GRB 200819A: Swift/UVOT Upper Limits
- IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- Swift Trigger 992444: a possible GRB 200821A
- GRB 200819A: Swift-BAT refined analysis
- GRB 200815A: MASTER optical observations
- IPN triangulation of GRB 200815A (short)
- GRB 200819A: Optical Observations from HCT
- GRB 200819A: Swift-XRT refined Analysis
- GRB 200819A: MITSuME Ishigaki optical upper limits
- GRB 200729A: Lowell Discovery Telescope observations
- GRB 200819A: MITSuME Akeno optical upper limits
- GRB 200819A: Kitab, TSHAO optical upper limit
- GRB 200819A: Enhanced Swift-XRT position
- Swift GRB 200819A: Global MASTER-Net observations report
- GRB 200819A: Swift detection of a burst
- Swift trigger 990358 is not an astrophysical source
- Swift trigger 989458 is likely not an astrophysical source
- Alert from the HAWC Burst Monitor HAWC-200814A
- IceCube200806A: No significant detection in HAWC
- GRB 200811A: BALROG localization (Fermi Trigger 618851447 / GRB 200811632)
- GRB 200809B: Fermi GBM detection
- Fermi GRB 200809B: Global MASTER-Net observations report
- GRB 200809B: Swift-XRT afterglow detection
- GRB 200809B: MAXI/GSC detection
- GRB 200809B: AstroSat CZTI detection
- GRB 200806A: Nanshan/NEXT optical upper limit
- GRB 200806A: VIRT optical observations
- GRB 200806A: Swift-BAT refined analysis
- GRB 200806A: Swift/UVOT Possible Detection
- GRB 200806A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-200806A
- GRB 200806A: AbAO optical upper limit
- GRB 200806A: AstroSat CZTI detection
- GRB 200806A: MITSuME Akeno optical upper limits
- GRB 200806A: Enhanced Swift-XRT position
- GRB 200806A: Swift detection of a burst
- GRB 200803A: Fermi GBM detection
- GRB 200803A: Swift-XRT afterglow detection
- Fermi GRB 200801B: Global MASTER-Net observations report
- AX J1846.4-0258: Swift-BAT refined analysis
- Konus-Wind detection of GRB 200729A
- GRB 200802A: BALROG localization (Fermi Trigger 618061611 / GRB 200802491)
- GRB 200801C: BOOTES-1 and BOOTES-2 optical limits
- Swift GRB200801.84: Global MASTER-Net observations report
- GRB 200801B: BALROG localization (Fermi Trigger 617988951 / GRB 200801650)
- GRB 200801B: Fermi GBM Final Real-time Localization
- GRB 200801A: Fermi GBM Final Real-time Localization
- GRB 200729A: RT-22 observations at 36.8 GHz
- GRB 200729A: Nanshan/NEXT optical upper limit
- GRB 200729A: Swift-BAT refined analysis
- GRB 200729A: further analysis of the NOT data
- GRB 200729A: Swift/UVOT Upper Limits
- GRB 200729A: Swift-XRT refined Analysis
- Fermi-GBM Sub-Threshold candidate for GRB 200729A
- GRB 200729A: IceCube neutrino search
- GRB 200729A: Pan-STARRS pre-explosion source detection
- GRB 200729A: Spitzer archival source detection
- GRB 200729A: TNG NIR upper limits
- GRB 200729A: NOT optical upper limits
- GRB 200729A: Enhanced Swift-XRT position
- GRB200729A: BOOTES-1 optical upper limit
- GRB 200729A: Swift detection of a burst
- IceCube Alert 200728.35: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 200726.66: Global MASTER-Net observations report
- GRB 200723A: GOTO candidate afterglow and host galaxy
- GRB 200723A: BALROG localization (Fermi Trigger 617214929 / GRB 200723691)
- GRB 200722A: BALROG localization (Fermi Trigger 617076900 / GRB 200722094)
- GRB 200714E: Swift-XRT afterglow detection
- GRB 200716C: VIRT optical detection.
- GRB 200716C: Insight-HXMT/HE detection
- AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
- GRB 200716C: Optical observations from HCT
- GRB 200716B: Insight-HXMT/HE detection
- GRB 200716C: Swift-BAT refined analysis
- GRB 200716C: Fermi GBM detection
- GRB 200716C: AGILE/MCAL detection
- GRB 200716C: possible host galaxy from the SDSS
- GRB 200716C: Swift-XRT refined Analysis
- GRB 200716C: Enhanced Swift-XRT position
- GRB200716C: BOOTES-1 optical afterglow detection
- GRB 200716C: Swift detection of a burst with an optical counterpart
- IPN triangulation of GRB 200716A
- GRB 200716A: Fermi GBM detection
- GRB 200716B: AstroSat CZTI detection
- GRB 200716A: AstroSat CZTI detection