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"
3050 results found.
- GRB 170510A: Swift-XRT observations
- Swift XRT observations of GRB 170424A
- LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 170428A: Swift-XRT refined Analysis
- GRB 170419A: Swift-XRT refined Analysis
- Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
- GRB 170405A: Swift-XRT refined Analysis
- GRB 170405A: Fermi-LAT detection
- IceCube-170321A: Swift-XRT observations
- GRB 170330A: Swift-XRT refined Analysis
- GRB 170331A: Swift-XRT refined Analysis
- GRB 170329A: Fermi-LAT detection
- INTEGRAL pointed follow-up of IceCube-170321A
- LIGO/Virgo G277583: INTEGRAL search for an X-ray and gamma-ray counterpart
- GRB 170318B: Swift-XRT refined Analysis
- GRB 170318A: Swift-XRT refined Analysis
- GRB 170317A: MITSuME Okayama Ks-band upper-limit
- GRB 170317A: Swift-XRT refined Analysis
- IceCube-170312A: Swift-XRT observations
- LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 170311A: Swift-XRT refined Analysis
- LIGO/Virgo G275404 and AGL J1914+1043: INTEGRAL follow-up
- GRB 170306B: Swift-XRT observations
- GRB 170306A: Swift-XRT refined Analysis
- LIGO/Virgo G275697: Further Swift-XRT sources
- GRB170305A: Fermi GBM detection
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275697: Swift-XRT sources
- LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275404: Swift-XRT sources
- GRB 170222A: Swift-XRT observations
- LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 170214A: Swift-XRT afterglow detection
- GRB 170214A: Swift-XRT observations
- GRB 170208B: IRSF upper limits
- GRB 170208A: IRSF upper limits
- GRB 170209A: Swift-XRT observations
- GRB 170208A: Swift-XRT refined Analysis
- GRB 170208B: Swift-XRT refined Analysis
- GRB 170206B: Swift-XRT refined Analysis
- GRB 170205A: Swift-XRT refined Analysis
- GRB 170202A: Swift-XRT refined Analysis
- GRB 170202A: Kanata optical and infrared observations
- GRB 170131A: Swift-XRT observations
- GRB 170127C: Swift-XRT observations
- GRB 170127B: Swift-XRT refined Analysis
- GRB 170127A: Swift-XRT refined Analysis
- GRB 170126A: Swift-XRT refined Analysis
- GRB 170121B: Swift-XRT and UVOT observations
- LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G270580: Swift-XRT sources
- GRB 170117A: Swift-XRT observations
- GRB 170115B: Swift-XRT observations
- LIGO/Virgo G268556: Swift-XRT observations of iPTF17cw
- GRB 170115A: Swift-XRT refined Analysis
- GRB 170113A: Swift-XRT refined Analysis
- GRB 170112A: Swift-XRT observations
- GRB 170111A: Swift-XRT refined Analysis
- LIGO/Virgo G268556: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
- Swift Trigger 730874 is not astrophysical
- LIGO/Virgo G268556: Swift-XRT detection of ATLAS17aeu
- LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
- LIGO/Virgo G268556: Swift-XRT sources
- GRB 161224A: Swift-XRT refined Analysis
- GRB 161220A: Swift-XRT refined Analysis
- GRB 161219B: Swift-XRT refined Analysis
- GRB 161217A: Swift-XRT refined Analysis
- GRB 161214B: Swift-XRT refined Analysis
- GRB 161202A: Swift-XRT refined Analysis
- GRB 161129A: MITSuME Okayama Ks-band Observation
- GRB 161129A: Swift-XRT refined Analysis
- GRB 161123A: Swift-XRT observations
- GRB 161117B: Swift-XRT refined Analysis
- GRB 161117A: Swift-XRT refined Analysis
- GRB 161113A: Swift-XRT refined Analysis
- GRB 161109A: Swift/UVOT Upper Limits
- GRB 161104A: Chandra X-ray observations
- GRB 161109A: Swift-XRT observations
- GRB 161105A: Swift/UVOT Upper Limits
- GRB 161108A: Swift-XRT refined Analysis
- GRB 161105A: Swift-XRT refined Analysis
- GRB 161104A: Swift-XRT refined Analysis
- IceCube-161103: Swift-XRT observations
- GRB 161023A: Swift-XRT afterglow detection
- GRB 161022A: Swift-XRT refined Analysis
- GRB 161015A: further Swift-XRT follow-up observations
- GRB 161017A: Swift-XRT refined Analysis
- GRB 161015A: Swift/UVOT observations
- GRB 161015A: Swift-XRT observations
- GRB 161014A: Swift-XRT refined Analysis
- GRB 161014A: Swift/UVOT Detection
- GRB 161014A: Swift-XRT and UVOT afterglow detection
- GRB 161011A: Swift-XRT refined Analysis
- GRB 161010A: Swift-XRT afterglow detection
- GRB 161007A: Swift-XRT refined Analysis
- GRB 161001A: IRSF upper limits
- GRB 161004B: Swift-XRT refined Analysis