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"3106 results found.
- GRB 160203A: Enhanced Swift-XRT position
- GRB 160203A: GROND Afterglow Candidate
- GRB 160203A: Swift detection of a burst
- GRB 160123A: Swift-BAT refined analysis
- IPN Triangulation of GRB 151231A
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- GRB 160107A: MAXI/GSC detection
- IPN Triangulation of GRB 151225A (short/hard)
- LIGO/Virgo G211117: Summary of Pan-STARRS transients
- GRB 160104B: MAXI/GSC detection
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160101A: MAXI/GSC detection
- LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
- LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
- IPN Triangulation of GRB 151227B
- V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
- LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
- LIGO/Virgo G211117: iPTF Optical Transient Candidates
- GRB 151228B: Fermi GBM observation
- LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
- LIGO/Virgo G211117: Optical follow-up with Kanata telescope
- GRB 151228B: Swift detection of a burst with an optical detection
- GRB 151215A: TSHAO optical observations
- Swift detection of 4U 1850-03
- GRB 130831A: MASTER early OT detection and LC
- GRB 151205B: MASTER-NET early optical observations
- GRB 151205A: Swift detection of a burst
- GRB 151127A iTelescope observation
- GRB GRB 151118A: MASTER-NET optical observations
- GRB 151111A: GROND marginal detection of a afterglow candidate
- GRB 151111A: LCOGT-FTS afterglow observations
- GRB 151027A: Mondy optical observations
- GRB 150910A: CrAO optical observations
- LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
- GRB 151022A: MASTER-Ural observations
- GRB 151006A: Mondy optical upper limit
- Swift Trigger 658045 is not a GRB
- LIGO/Virgo G184098: Further VST-ESO PARANAL observations
- LIGO/Virgo G184098: VST-ESO PARANAL observations
- LIGO/Virgo G184098: Swift follow-up observations
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150907B: Swift-BAT refined analysis
- GRB 150907B: Enhanced Swift-XRT position
- GRB 150907B: GROND Upper Limits
- GRB 150907B: Swift-XRT observations
- GRB 150907A: Swift-XRT observations
- GRB 150907A: MAXI/GSC detection
- ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
- GRB 150902A: MASTER-SAAO optical observations
- Konus-Wind observation of GRB 150902A
- GRB 150831B: MASTER-IAC early optical observations
- IPN Triangulation of GRB 150824A
- Konus-Wind observation of GRB 150818A
- GRB 150821A: Swift detection of a burst with an optical afterglow
- GRB 150819A: Swift-BAT refined analysis
- GRB 150819A: Swift detection of a burst
- Fermi GBM trigger 150806450 is not a GRB
- Trigger 649113: Swift detection of SGR 1E 1841-045
- Fermi Gamma-ray Burst Monitor triggers that are not GRBs
- GRB 150710B refined analysis
- GRB 150710B detected in ground analysis of BAT data
- GRB 150626B, Swift-BAT refined analysis
- V404 Cyg: MASTER Swift, Integral alert observations
- GRB 150622A: MAXI/GSC detection
- GRB 150527A: Swift-XRT refined Analysis
- GRB 150527A: Fermi GBM observation
- GRB 150518A: Mondy optical observations
- GRB 150430A: MAXI/GSC detection
- GRB 150413A: CrAO optical observations
- GRB 150424B: MAXI/GSC detection
- GRB 150424A: Swift detection of a short burst
- IPN Triangulation of GRB 150330A (long/very intense)
- GRB 150323A: AAO optical observations
- GRB 150309A: CrAO optic upper limit
- GRB 150301A: Fermi GBM observation
- Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
- Fermi GBM Observations of Magnetar 4U 0142+61
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150212A: Swift-XRT refined Analysis
- GRB 150212A: MASTER optical observations
- GRB150212A: P60 Afterglow Candidate
- GRB 150210A: MASTER SN detection during LAT error box inspection
- GRB 150204A: GROND observations
- GRB 150203A iTelescope observation
- GRB 150204A: LCOGT-Sutherland and Siding Springs observations
- GRB 150202B: Swift XRT/UVOT observations
- GRB 150201A: GROND upper limits
- Konus-Wind observation of GRB 150127B
- GRB 150123A: MASTER inspection
- Swift Trigger 628458 likely not astrophysical
- Konus-Wind observation of GRB 150118B
- GRB 150120B: P60 optical afterglow
- Swift detection of 4U 1700+24 (= V* V934 Her)
- GRB 141229A: MAXI/GSC detection
- GRB 141225A: MASTER-SAAO first OT detection
- GRB 141225A: Enhanced Swift-XRT position
- GRB 141225A: UVOT detection
- GRB 141225A: Optical aftergow confirmation
- GRB 141225A: LT optical candidate