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"- GRB 171124A: Swift-XRT afterglow detection
- Pan-STARRS follow-up of IceCube-171106A
- LIGO/Virgo G299232: LOFAR follow-up
- GRB 171124A: Insight-HXMT/HE detection
- GRB 171126A: Fermi GBM detection
- GRB 171123A: TShAO optical upper limit
- GRB 171124A: AstroSat CZTI detection
- INTEGRAL pointed follow-up of IceCube-171106A
- GRB 171123A: OSN Upper Limit
- GRB 171124A: Swift-XRT observations
- GRB 171124A: Fermi GBM observation
- GRB 171119A: AstroSat CZTI detection
- GRB 171123A: Tautenburg observations
- GRB 171123A: Nanshan-1m optical upper limit
- GRB 171123A: RATIR Optical and NIR Observations
- GRB 171124A: MITSuME Akeno optical upper limits
- GRB 171123A: Swift/UVOT Upper Limits
- GRB 171123A: GMG observation limit
- GRB 171124A: Fermi-LAT detection
- GRB 171124A: Swift ToO observations
- GRB 171123A: MITSuME Akeno optical upper limits
- GRB 171123A: Swift-BAT refined analysis
- GRB 171123A: Swift-XRT refined Analysis
- GRB 171123A: Confirmation of the X-ray afterglow
- GRB 171123A: Enhanced Swift-XRT position
- GRB 171120A: Insight-HXMT detection
- GRB 171123A: Swift detection of a burst
- Konus-Wind observation of GRB 171119A
- IPN Triangulation of GRB 171119A (long)
- GRB 171120A: Xinglong-2.16m optical upper limit
- GRB 171120A: Swift/UVOT Upper Limits
- GRB 171120A: AstroSat CZTI detection
- Konus-Wind observation of GRB 171120A
- GRB171120A: GWAC-F60A upper limit
- GRB 171120A: MITSuME Akeno optical upper limits
- GRB 171120A: Swift-BAT refined analysis
- GRB 171120A: Fermi GBM Detection
- GRB 171120A: Swift-XRT refined Analysis
- GRB 171120A: Fermi-LAT detection
- GRB 171120A: Enhanced Swift-XRT position
- GRB 171115B: Insight-HXMT detection
- GRB 171120A: Swift detection of a burst
- Fermi-LAT Gamma-ray Observations of IceCube-171106A
- GRB 171108B: Insight-HXMT detection
- GRB 171115A: RATIR Optical and NIR Observations
- GRB 171115A: MITSuME Okayama optical upper limits
- GRB 171115A: MITSuME Akeno optical upper limits
- GRB 171115A: Swift-BAT refined analysis
- GRB 171115A: Swift-XRT refined Analysis
- GRB 171115A: Enhanced Swift-XRT position
- GRB 171115A: Swift detection of a burst
- GRB 171112A: Fermi GBM Detection
- LIGO/Virgo G288732/GW170608: updated localization from parameter estimation
- Konus-Wind observation of GRB 171112A
- FACT follow-up of IceCube20171106
- Konus-Wind observation of GRB 171108A
- GRB 171112A: MAXI/GSC detection
- IPN Triangulation of GRB 171108A (short)
- GRB 171103A: Insight-HXMT observation
- IceCube-171106A: Swift Observations
- HAWC follow-up of IceCube-171106A
- GRB 171010A: afterglow and SN 2017htp optical observations
- GRB 171108A: Fermi GBM detection
- GRB 171102A CALET Gamma-Ray Burst Monitor detection
- GRB 171101A CALET Gamma-Ray Burst Monitor detection
- INTEGRAL observation of IceCube-171106A
- GRB 171030A: MASTER OT J034412.48-263556.5 featureless continuum spectrum from Lijiang 2.4m (China) telescope and 2m the Himalayan Chandra
- GRB 171010A: possible SN component
- Fermi-GBM Trigger 531686417 / 171106778 is not related to ICECUBE-171106A
- IceCube-171106A - IceCube observation of a high-energy neutrino candidate
- AMON ICECUBE EHE 130214 (close by time to Fermi trigger): MASTER early follow-up observations
- GRB 171103A: AstroSat CZTI detection
- GRB 171030A: MASTER inspection of the IPN error box of the short GRB.
- Konus-Wind observation of GRB 171103A (short/hard)
- GRB 171103A: Fermi GBM observation
- GRB 171103A: Swift-BAT refined analysis of a short GRB
- LIGO/Virgo G298936: NOT spectroscopy of GWFUNC-17ure
- Fermi GBM detections of Swift J0243.6+6124 and modification of the GBM trigger configuration
- GRB 171010A: VLT spectroscopic identification of the associated SN 2017htp
- GRB 171103A: Swift detection of a short hard burst
- Konus-Wind observation of GRB 171102A
- GRB 171102B: AbAO optical upper limit
- GRB 171102B: TShAO optical upper limit
- IPN Triangulation of GRB 171102A
- GRB 171102B: Nanshan 0.36m and 0.60m optical upper limits
- GRB 171102B: RATIR Optical and NIR Observations
- GRB 171102B: Swift-BAT refined analysis
- GRB 171102B: MITSuME Akeno optical upper limits
- GRB 171102B: Swift/UVOT Upper Limits
- GRB 171102B: Swift-XRT refined Analysis
- GRB 171102B: Enhanced Swift-XRT position
- GRB 171102A: Fermi GBM detection
- GRB 171102B: Swift detection of a burst
- GRB 171102A: Fermi-LAT detection
- GRB 171030A: IPN error box through NSs probability merging rate map
- GRB 171030A: Fermi GBM detection
- GRB 171030A: Swift non-localization with BAT, XRT and UVOT
- GRB 171030A: Swift ToO observations
- IPN Triangulation of GRB 171030A (short)
- Fermi-GBM triggers due to Swift J0243.6+6124