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"
2724 results found.
- LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
- LIGO/Virgo G277583: TAROT Calern (TCA) observations
- LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
- LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
- IPN Triangulation of GRB 170305A (short)
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
- LIGO/Virgo G275697: iPTF Optical Transient Candidates
- LIGO/Virgo G275404: iPTF Optical Transient Candidates
- LIGO/Virgo G275404: CNEOST optical observations
- GRB 170220A: POLAR Observation
- LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
- LIGO/Virgo G274296: Asiago 1.82m Optical Observations
- LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
- Konus-Wind observation of GRB 170219A (short/hard)
- LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
- GRB 170210A: POLAR observation
- IPN Triangulation of GRB 170210A
- GRB 170210A: Fermi GBM observation
- Konus-Wind observation of GRB 170209A
- GRB 170208A: Swift-BAT refined analysis
- GRB 170202A: SQUEAN Observation
- LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
- GRB 170115B: AGILE/SuperAGILE localisation
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
- GRB 170121B: MASTER early optical observations of the Swift possible XT
- LIGO/Virgo G268556/GW170104: MAXI/GSC observations
- GRB 170121B/Fermi trigger 506702667 MASTER-Amur OT detection
- LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
- GRB 170112A : AbAO optical observations
- GRB 170113A: Fermi GBM observations
- GRB 170112A: MASTER-OAFA (Argentina) early optical observations
- LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
- LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
- LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
- LIGO/Virgo G268556: SWASP optical imaging
- LIGO/Virgo G211117 / GW151226: LOFAR follow-up
- LIGO/Virgo G268556: Swift-XRT sources
- GRB 170101B: POLAR observation
- GRB 170101B: Lomonosov BDRG gamma ray discovery
- GRB 170101B: Astrosat CZTI detection
- GRB 170101B: Fermi GBM detection
- GRB 161214A: MASTER-IAC early optical observations
- GRB161219.78 MASTER-Net OT detection
- GRB 161219B: Rapid ALMA Observations & Detection
- GRB 161220A: Swift-XRT refined Analysis
- GRB 161219B: VLA Detection
- GRB 161219B: Swift/UVOT Detection
- GRB 161219B: LCO Sutherland observations
- GRB 161219B: Enhanced Swift-XRT position
- GRB 161219B: Swift detection of a burst with an optical afterglow
- GRB 161218A: CALET Gamma-Ray Burst Monitor detection
- Konus-Wind observation of GRB 161218A
- GRB 161218A: POLAR observation
- GRB 161218A: Swift detection of a burst
- GRB 161129A: ISON/UAFO optical observations
- GRB 161117A: SMARTS optical/IR afterglow observations
- GRB 161119A: MASTER-SAAO possible OT detection during Fermi Alert
- Konus-Wind observation of GRB 161117A
- GRB 161108A: NOT redshift
- IceCube-161103: MASTER follow-up observations
- GRB 161023A: LCOGT-FTS optical observations
- GRB 161023A (Integral trigger 7613) MASTER-Net bright OT detection
- Swift Trigger 718766 is not an astrophysical event.
- GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
- GRB 161014A: AROMA-N Optical Observation
- GRB 161014A : Xinglong TNT optical observation
- GRB 161010A: Swift/UVOT Possible Detection
- GRB 161010A: Swift-XRT afterglow detection
- GRB 160927A: 15 GHz upper limits from AMI
- GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
- GRB 161001A: GROND afterglow candidate
- GRB 161001A: X-shooter spectroscopy, candidate host galaxy and redshift
- GRB 161001A: Prompt enhanced Swift-XRT position
- GRB 160917A: Fermi GBM observation
- GRB 160910A: Swift-XRT afterglow detection
- GRB 160910A: Fermi GBM observation
- GRB 160905A: Swift detection of a burst with an optical counterpart
- Konus-Wind observation of GRB 160821A
- GRB 160816A: TSHAO optical observations
- BAT detection and localization of GRB 160819A
- GRB 160816A: ISON/UAFO optical observations
- IceCube 160806A: Lomonosov BDRG gamma ray prompt observations
- IPN Triangulation of GRB 160806A
- Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
- Swift Trigger 707517 is probably not a GRB
- IPN Triangulation of GRB 160802A
- GRB 160804A: Swift detection of a burst
- GRB 160714A: MASTER early optical observations
- GRB 160714A: Swift-XRT observations
- GRB 160712A: Swift-XRT observations
- GRB 160625B: Global MASTER-Crimea prompt optical emission detection (fwd)
- GRB 160705A/MAXI J0748-149: MAXI/GSC detection
- GRB 160629A: AbAO optical observations
- GRB 160525B: Mondy optical upper limit
- Swift detection of SGR 1935+2154
- GRB 160521B: Fermi-LAT detection
- GRB 160521B: Fermi GBM detection
- GRB 160509A: VLA Detection