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"19551 results found.
- GRB 180325A: VLT/X-shooter spectroscopic observations
- GRB 180325A: Swift/UVOT Detection
- GRB 180325A: GROND observations
- GRB 180325A: TAROT Calern observatory optical observations
- GRB 180325A: D50 early optical follow-up
- GRB 180325A: Enhanced Swift-XRT position
- GRB 180325A: Optical Photometry with SLKT
- GRB 180325A: RATIR Optical Observations
- GRB 180325A: prompt REM optical/NIR detection
- GRB 180325A: NOT redshift
- GRB 180325A: Swift detection of a burst with an optical counterpart
- GRB 180324A: Swift/UVOT Upper Limits
- GRB 180324A: Enhanced Swift-XRT position
- GRB 180324A: RATIR Optical Observations and Possible Afterglow Detection
- GRB 180324A: Swift detection of a burst
- IPN Triangulation of GRB 180317A (short/hard)
- GRB 180316A: RATIR Optical Observations
- GRB 180316A: TSHAO optical observations
- GRB 180316A: RATIR Optical Observations, Possible Re-brightening
- GRB 180316A: Swift/UVOT Detection
- GRB 180316A: RATIR Optical Observations
- GRB 180316A: Enhanced Swift-XRT position
- GRB 180316A: LCO Cerro Tololo observations
- GROND observations of GRB 180316A
- GRB 180316A: Swift detection of a burst
- GRB 180314B: RATIR Optical Observations
- GRB 180314B: Zeiss-1000/CrAO optical upper limit
- GRB 180314B: Swift/UVOT Upper Limits
- GRB 180314B: Enhanced Swift-XRT position
- GRB 180314B: Swift detection of a burst
- Swift Trigger on MAXI J1820+070
- GRB 180314A: TAROT La Silla observatory optical observations
- GRB 180314A: LCO Siding Springs observations
- GRB 180314A: Swift/UVOT Detection
- GRB 180314A: REM optical/NIR observations
- GRB 180314A: MASTER-Net OT dtetction
- GRB 180314A: Enhanced Swift-XRT position
- GRB180314A: GROND detection of the afterglow
- GRB 180314A: Swift detection of a burst with an optical counterpart
- GRB 180311A: Swift/UVOT Upper Limits
- MAXI J1820+070: Swift/UVOT counterpart correction
- Swift detection of MAXI J1820+070
- GRB 180311A: Enhanced Swift-XRT position
- GRB 180311A: Swift detection of a burst
- GRB 180305A CALET Gamma-Ray Burst Monitor detection
- GRB 180305A: RATIR Optical Observations
- GRB 180305A: Swift/UVOT Upper Limits
- GRB 180305A: Mondy optical observations
- GRB 180305A: Swift-XRT afterglow detection
- GRB 180305A: RATIR Optical Afterglow Candidate
- GRB 180305A: Swift ToO observations
- GRB 180305A: Fermi-LAT detection
- GRB 180224A: Swift/UVOT Detection
- GRB 180224A: OASDG optical observations
- IPN Triangulation of GRB 180223A (long)
- GRB 180210A: Insight-HXMT/HE observation
- Swift Trigger 811686 is probably not an astrophysical source.
- GRB 180224A: AbAO optical observations
- GRB 180224A: RATIR Optical Observations
- GRB 180224A: Enhanced Swift-XRT position
- GRB 180224A: Swift detection of a burst with an optical counterpart
- MAXI J1813-095 source: AbAO optical observations
- GRB 180222A: Swift/UVOT Upper Limits
- GRB 180222A: Swift-BAT refined analysis
- GRB 180222A: Enhanced Swift-XRT position
- GRB 180222A: Swift detection of a burst
- Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
- Swift Trigger 811167: Detection of MAXI J1813-095
- GRB 180205A: Mondy optical observations
- IPN Triangulation of GRB 180218A (long/bright)
- GRB 180204A: 15 GHz upper limits from AMI
- Konus-Wind observation of GRB 180210A
- GRB 180205A: SEDM Observations
- GRB 180210A: Swift-XRT afterglow detection
- GRB 180210A: Tiled Swift observations
- GRB 180205A: BAO optical observations
- GRB 180210A: Swift ToO observations
- Trigger 809374: Swift detection of a possible non-burst faint source
- Trigger 809217: Swift trigger on RS CVn Star HD 8357
- GRB180205A: Optical observations with DOAO 1m telescope
- GRB 180205A: AbAO optical observations
- GRB 180205A: Swift/UVOT Detection
- GRB 180205A: Nanshan-1m optical observations
- GRB 180205A: Swift-XRT refined Analysis
- GRB 180205A: Further GROND Observations reveal Afterglow is still bright
- GRB 180205A: Nickel telescope optical observations
- Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
- GRB 180205A: Mondy optical observations
- GRB 180205A: GROND detection of the NIR/optical afterglow
- GRB 180205A: Swift detection of a burst with a bright optical counterpart
- GRB 180204A: Swift/UVOT Upper Limits
- GRB 180204A: Enhanced Swift-XRT position
- GRB 180204A: Swift-XRT refined Analysis
- GRB 180204A: Swift detection of a short burst
- GW170817/GRB170817A: Preliminary results of Chandra monitoring
- LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
- GRB 180115A: SEDM Observations
- GRB 180111A AROMA-N optical observation
- IPN Triangulation of GRB 180113C
- GRB 180115A: NOT detection of optical counterpart