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"11519 results found.
- GRB 190605A: AstroSat CZTI detection
- Fermi trigger No 581645543 Global MASTER-Net observations report
- GRB 190608A: Fermi GBM Final Real-time Localization
- GRB 190606A: Insight-HXMT/HE detection
- IPN Triangulation of GRB 190606A (short)
- GRB 190606A: Fermi GBM detection
- GRB 190530A: Further OAJ/OSN photometry and analysis
- GRB 190606A: Fermi-LAT detection
- Fermi trigger No 581478912 / GRB 190606A: AGILE/MCAL observations
- GRB 190604A: Insight-HXMT/HE detection
- Fermi trigger No 581478912 Global MASTER-Net observations report
- Fermi trigger No 581469752 Global MASTER-Net observations report
- GRB 190605A: Fermi GBM Final Real-time Localization
- GRB 190604A: AstroSat CZTI detection
- GRB 190530A: optical follow-up observations at Konkoly
- GRB190530A: Photometric follow-up with GROWTH-India telescope
- Fermi trigger No 581337762 Global MASTER-Net observations report
- GRB190604A: BALROG localization (Fermi Trigger 581337762 / GRB 190604446)
- GRB 190604A: Fermi GBM Final Real-time Localization
- GRB 190531B: CALET Gamma-Ray Burst Monitor detection
- Fermi trigger No 581281470 Global MASTER-Net observations report
- GRB 190603A: Fermi GBM Final Real-time Localization
- Konus-Wind observation of GRB 190531B
- GRB 190530A: R-band observation from HCT
- LIGO/Virgo S190602aq: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190602aq: Upper limits from Fermi-GBM Observations
- Konus-Wind observation of extremely bright GRB 190530A
- GRB 190530A: Insight-HXMT/HE detection
- GRB 190531B: Insight-HXMT/HE detection
- GRB 190530A: Mondy and AbAO optical observations
- GRB 190531B: VLT optical upper limit
- Fermi trigger No 581068049 Global MASTER-Net observations report
- GRB 190530A: Konkoly optical observations of the afterglow
- GRB 190530A: SAO RAS optical observations
- GRB 190531B: MASTER optical observation
- GRB 190531B: Swift-XRT afterglow detection
- GRB 190531B: Fermi GBM observations
- Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
- GRB 190531B: Swift ToO observations
- GRB 190531B: Fermi-LAT detection
- GRB 190530A: Steep afterglow decay found by OSN
- GRB 190531B: name correction re. GCN 24696
- GRB 190530A: AbAO optical observations
- GRB 190530A: Xinglong 2.16m optical observation
- Fermi Trigger 581026217 / GRB 190531840 / GRB190531A: BALROG localization
- GRB 190531B: Fermi GBM Final Real-time Localization
- GRB 190530A: AstroSat CZTI detection
- GRB 190530A: optical afterglow detection by 5 MASTER telescopes
- GRB 190530A: Fermi GBM observation
- GRB 190531A: Fermi GBM Final Real-time Localization
- GRB 190530A: COATLI Optical Detection of the Fading Afterglow
- GRB 190530A: Swift-XRT afterglow detection
- GRB 190530A: GWAC-F30 optical detection
- GRB 190530A: OAJ optical detection
- GRB 190530A: NOT photometry and spectroscopy
- Fermi GRB190530.43 Global MASTER-Net observations report
- GRB 190530A: Bright afterglow confirmed by OSN
- GRB 190530A: AGILE/GRID analysis
- GRB 190530A: Swift ToO observations
- GRB 190530A: MASTER OT detection
- GRB 190530A: Fermi-LAT detection
- GRB 190530A: AGILE-MCAL detection
- Fermi Trigger 580904353 / GRB 190530430 / GRB190530A: BALROG localization
- GRB 190530A: Fermi GBM Final Real-time Localization
- GRB 190525A: AstroSat CZTI detection
- GRB 190525A: Insight-HXMT/HE detection
- Fermi GRB190525.67 Global MASTER-Net observations report
- Fermi GRB190525.03 Global MASTER-Net observations report
- GRB 190525A: Fermi GBM Final Real-time Localization
- Konus-Wind observation of GRB 190519A
- LIGO/Virgo S190521r: Coverage and upper limits from Fermi-LAT observations
- LIGO/Virgo S190521r: Upper limits from Fermi-GBM observations
- LIGO/Virgo S190521g : Upper limits from Fermi-GBM observations
- LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
- LIGO/Virgo S190519bj: Fermi-LAT search for a high-energy gamma-ray counterpart
- Fermi GRB190520.6 Global MASTER-Net observations report
- GRB 190519A: AstroSat CZTI detection
- GRB 190519A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo S190519bj: Fermi GBM Observations
- GRB 190519A: Fermi GBM observation
- GRB 190519A: Fermi GBM Final Real-time Localization
- Fermi GRB190517.81 Global MASTER-Net observations report
- Fermi Trigger 579814215 / GRB 190517813 / GRB190517A: BALROG localization
- GRB 190517A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190517h: Fermi GBM Observations
- GRB 190515A: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB190517.1 Global MASTER-Net observations report
- Fermi GRB190515.49 Global MASTER-Net observations report
- GRB 190515A: Insight-HXMT/HE detection
- GRB 190515A: Fermi GBM detection
- GRB 190515A: Fermi-LAT detection
- Fermi GRB190515.43 Global MASTER-Net observations report
- GRB 190510A: CALET Gamma-Ray Burst Monitor detection
- GRB 190515A: Fermi GBM Final Real-time Localization
- Fermi GRB190514.67 Global MASTER-Net observations report
- LIGO/Virgo S190513bm: Fermi GBM Observations
- Konus-Wind observation of GRB 190511A
- LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart