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"14820 results found.
- IPN triangulation of GRB 240615A (short)
- X-ray transient EP240618a: Fermi/GBM non-detection
- GRB 240619A: GRBAlpha detection
- EP240618a: Swift/XRT upper limit
- EP240617a: tentative Swift/XRT detection of the afterglow
- GRB 240619A: Swift-XRT probable afterglow detection
- GRB 240619A: CALET Gamma-Ray Burst Monitor detection
- GRB 240619C: NuSTAR automated detection of the GRB
- Fermi GBM Sub-Threshold Detection of GRB 240619C
- GRB 240619A: GOTO candidate optical afterglow
- GRB 240615A: NOT optical observations
- GRB 240619C: AstroSat CZTI detection
- GRB 240615A: possible transient detection from Wendelstein observations
- EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
- EP240618a: BOOTES-6/DPRT optical upper limit
- GRB 240619B: Fermi GBM Final Real-time Localization
- GRB 240619A: Fermi GBM Final Real-time Localization
- EP240617a: BOOTES-6/DPRT optical upper limit
- EP240617a is likely a GRB event
- EP240617a: EP-WXT detection of a fast X-ray transient
- EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
- GRB 240615A: GECAM detection
- Konus-Wind detection of GRB 240615A (short/hard)
- GRB 240616A: Fermi GBM Final Real-time Localization
- GRB 240615A: Fermi GBM Final Real-time Localization
- GRB 240603A: VZLUSAT-2 detection
- GRB 240612A: GRBAlpha detection
- GRB 240613A: Fermi GBM Final Real-time Localization
- GRB 240612B: Fermi GBM Final Real-time Localization
- GRB 240612A: Fermi GBM Final Real-time Localization
- GRB 240607A: GECAM detection of a bright long burst
- Konus-Wind detection of GRB 240607A
- GRB 240611A: Fermi GBM Final Real-time Localization
- GRB240529A: 3.6m TNG NIR detection 8d after the burst
- GRB 240529A: LBT optical detection and late temporal decay
- GRB 240529A : MITSuME Akeno optical afterglow detection
- Trigger 1236151: Swift detection of EXO 0748-676
- GRB 240610A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 240607A
- Konus-Wind detection of GRB 240606B
- GRB 240608A: Fermi GBM Final Real-time Localization
- GRB 240529A: NOEMA detection
- GRB 240607A: AstroSat CZTI detection of bright long burst
- GRB 240607A: Fermi GBM detection of a very bright burst
- GRB 240529A: radio detection with AMI-LA
- GRB 240607A: Fermi GBM Final Real-time Localization
- GRB 240606B: GECAM-B detection a long burst
- GRB 240606B: Swift-XRT afterglow detection
- Konus-Wind detection of GRB 240603A
- IPN triangulation of GRB 240531A (short)
- GRB 240605C: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 240603A
- GRB 240605B: Fermi GBM Final Real-time Localization
- GRB 240604A: Fermi GBM Final Localization
- GRB 240605A: Fermi GBM Final Real-time Localization
- GRB 240604A: GECAM detection of a long burst
- Swift Trigger 1232755: likely consistent with noise and not astrophysical
- GRB 240603A: Fermi GBM Final Localization
- GRB 240603C: Fermi GBM Final Real-time Localization
- GRB 240603B: Swift detection of a possible burst
- GRB 240529A: MASTER prompt OT detection
- GRB 240603A: GECAM detection of a short burst
- GRB 240529A: OSN optical detection
- The EP-WXT source triggered on June 1st is likely a flaring star
- GRB 240602A: Fermi GBM Final Real-time Localization
- GRB 240529A: AKO Optical Afterglow Follow-Up Observations
- LXT 240528A: GSP optical upper limit
- GRB 240529A: 1.3m DFOT Optical observations
- GRB 240531A: AstroSat CZTI detection of a short burst
- Konus-Wind detection of GRB 240529A
- IPN triangulation of the initial episode of GRB 240529A
- GRB 240529A: MAAO 0.7m telescope optical afterglow detection
- GRB 240529A: Insight-HXMT/HE detection
- GRB 240529A: optical photometry from Konkoly
- GRB 240529A: GROWTH-India optical follow-up
- GRB 240529A: T193/MISTRAL observations
- GRB 240529A: AKO Optical Afterglow Detection
- LXT 240528A: LEIA detection of a fast X-ray transient
- GRB240529A: BOOTES-6/DPRT optical detection
- GRB 240529A: Swift/UVOT Detection
- GRB 240529A: AstroSat CZTI detection
- GRB 240529A: GOTO optical afterglow detection
- GRB 240527B: Swift-XRT afterglow detection
- GRB 240529A: Swift detection of a burst with an optical counterpart
- GRB 240527B: Fermi-LAT detection
- GRB 240527B: Fermi GBM Final Localization
- GRB 240527A: Fermi GBM Final Real-time Localization
- GRB 240523A: Swift detection of a burst
- Fermi GBM Sub-Threshold Detection of GRB 240516B
- GRB 240513A: Swift-XRT afterglow detection
- EP240518a: GSP optical upper limit
- GRB 240521A: GECAM-B detection of a long burst
- GRB 240516B: AstroSat CZTI detection
- GRB 240514B: VZLUSAT-2 detection
- GRB 240504A: VZLUSAT-2 detection
- GRB 240502A: VZLUSAT-2 detection
- GRB 240519A: GRBAlpha detection
- GRB 240519A: AstroSat CZTI detection
- EP240518a: possibly identified with a flare star by EP-FXT
- EP240518a: EP-WXT detection of a new X-ray transient