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"3533 results found.
- GRB 161017A: MITSuME Akeno Optical Observation
- GRB 161014A: Swift-XRT refined Analysis
- GRB 161014A: Swift-BAT refined analysis
- GRB 161014A: Swift/UVOT Detection
- GRB 161014A: Swift-XRT and UVOT afterglow detection
- GRB 161014A : Xinglong TNT optical observation
- GRB161014A: optical afterglow candidate with the LCOGT-FTS
- GRB 161014A: MITSuME-Akeno optical observation
- GRB 161010A: Swift/UVOT Possible Detection
- GRB 161007A: MASTER-net early optical observations
- GRB 160927A: GTC observations
- GRB 161004B: Prompt enhanced Swift-XRT position
- GRB 161004A: Swift detection of a burst with a possible optical counterpart
- Fermi GBM trigger 496791348/160928900 is not a GRB
- GRB160925A / Fermi 496473540: MASTER optical transient confirmation by LCOGT-FTN
- GRB160821A: Astrosat CZTI (veto) detection
- IPN Triangulation of GRB 160820A (short/hard)
- GRB 160816A: TSHAO optical observations
- IPN Triangulation of GRB 160806A
- GRB 160804A: Swift-BAT refined analysis
- GRB 160801A: Swift detection of a burst
- HAWC follow up of IceCube 160731
- Trigger 706396: Swift detection of a short burst from PSR 1119-6127
- Konus-Wind observation of GRB 160720A
- GRB 160712A: Global MASTER-Net optical observation
- GRB 160628A CALET Gamma-Ray Burst Monitor detection
- GRB 160629A: AbAO optical observations
- GRB 160703A: Swift-BAT refined analysis
- GRB 160629A: AbAO optical observations
- GRB 160625B: TSHAO optical observations, correction GCN 19619
- IPN Triangulation of GRB 160620A (short/hard)
- GRB 160624A: Swift-XRT refined Analysis
- GRB 160624A: Swift detection of a short burst
- LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
- IPN Triangulation of GRB 160612A (short/hard)
- GRB160611.9 MASTER-Net OT detection
- GRB 160601A: AbAO optical observations
- FERMI GBM bursts from the magnetar SGR 1935+2154
- Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
- FACT follow-up of the IceCube event 160427A
- GRB 160501A: Swift-BAT refined analysis
- MASTER search for counterpart to the IceCube event 67093193 (run 127853)
- GRB 160425A MASTER notices: possible host galaxy in the optical error-box
- GRB 160425A : MASTER earlier optical observations
- LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
- GRB 160411A: Fermi GBM detection
- GRB 160411A: Swift detection of a short burst
- GRB 160410A: Swift/UVOT Detection
- GRB 160410A: Enhanced Swift-XRT position
- GRB 160410A: GROND optical detection
- GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
- GRB 160327A: Continued RATIR Optical and NIR Observations
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160327A: Swift-BAT refined analysis
- Swift detects GX 301-2 in very high state
- GRB 160321A: MASTER observations zero Galaxy latitude GRB
- Swift Trigger 678197 is a noise fluctuation
- LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
- GRB 160303A: BOAO R-band Detection
- GRB 160227A: LOAO 1.0m optical detection
- GRB 160227A: McDonald 0.8m Detection
- GRB 160228A: Mondy optcial observations
- GRB 160228A: MASTER-Amur prompt observations
- GRB 160227A: AROMA-N Optical Observation
- GRB 160228A: optical observations
- GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 detection
- GRB 160221A: Swift-XRT afterglow detection
- GRB 160221A: Swift-XRT observations
- GRB 160221A: MASTER-SAAO early observations
- GRB 160220A: MASTER-Amur observations
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160206A: MAXI/GSC detection
- GRB 160203A: TAROT La Silla - TAROT Calern - Zadko observations
- Fermi GBM trigger 475675010/160128498 is not a GRB
- GRB 160131A: Khureltogot optical observations
- GRB 160127A: LCOGT-Sutherland optical upper limit
- LIGO Virgo G211117: MWA Observations
- GRB160119A: BOOTES-2/TELMA Early Upper Limits
- GRB 160119A: Swift detection of a burst
- GRB 151228B: AbAO optical upper limit
- Konus-Wind observation of GRB 160113A
- IPN Triangulation of GRB 160113A
- LIGO/Virgo G211117: iPTF Observations of PS15dpn
- LIGO/Virgo G211117: VISTA imaging
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- GRB 160104A: MITSuME Okayama upper limits
- LIGO/Virgo G211117: Summary of Pan-STARRS transients
- LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
- LIGO/Virgo G211117: LOFAR follow-up
- LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
- LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
- GRB 160102A: MAXI/GSC detection
- LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28 - 30
- GRB 151231B: Fermi GBM observation
- LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
- LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
- LIGO/Virgo G211117: VLA follow-up
- Trigger 668877: Swift detection of V 404 Cyg
- LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
- V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations