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"19089 results found.
- 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
- GRB 180113A: Swift ToO observations
- GRB 180115A: Enhanced Swift-XRT position
- GRB 180115A: Swift detection of a burst with an optical counterpart.
- GRB 180111A: AbAO optical observations
- GRB 180113A: KAIT Optical Observations
- GRB 180111A: Swift/UVOT Detection
- GRB 180103A: Swift-XRT afterglow detection
- GRB 180111A: RATIR Optical and NIR Observations
- GRB 180111A: Enhanced Swift-XRT position
- GRB 180111A: Swift detection of a burst with an optical counterpart
- GRB 180103A: LCO Sutherland 1-m telescope observations
- GRB 180103A: Swift/UVOT Upper Limits
- GRB 180103A: Swift ToO observations
- GRB 180102A AROMA-N optical observation
- GRB 180102A: TSHAO optical upper limit
- GRB 180102A: Swift-BAT refined analysis
- GRB 180102A: Swift/UVOT Upper Limits
- GRB 180102A: NOT optical observations
- GRB 180102A: Enhanced Swift-XRT position
- GRB 180102A: Swift detection of a burst
- GRB 171222A: AROMA-N optical observation
- GRB 171222A: Nanshan-0.36m optical upper limit
- GRB 171222A: Swift/UVOT Upper Limits
- GRB 171222A: Nanshan-1m optical afterglow detection
- GRB 171205A: SMARTS optical/IR supernova monitoring
- GRB 171222A: Enhanced Swift-XRT position
- GRB 171222A: Swift detection of a burst
- GRB 171216A: Swift/UVOT Upper Limits
- GRB 171205A: RATAN observations
- GRB 171216A: Enhanced Swift-XRT position
- GRB 171216A: Swift detection of a burst
- Swift Trigger 797070 is probably not a GRB
- GRB 171212A: Swift-XRT refined Analysis
- GRB 171211A iTelescope observation
- GRB 171212A/Swift J1935.7+2036: Swift/UVOT Upper Limits
- GRB 171212A/Swift J1935.7+2036: TSHAO optical observations
- GRB 171212A: Enhanced Swift-XRT position
- GRB 171212A: Swift detection of a burst or a Galactic transient
- GRB 171211A: Swift-XRT refined Analysis
- GRB 171211A: Swift/UVOT Upper Limits
- GRB 171211A: Enhanced Swift-XRT position
- GRB 171210A: Swift-XRT and UVOT observations
- GRB 171211A: Swift detection of a possibly short burst
- GRB 171210A: Swift ToO observations
- GRB 171209A: Lulin 1m telescope observations
- GRB 171205A: iTelescope optical observations
- GRB 171205A: Mondy optical observations
- GRB 171205A: SAO-RAS optical observations
- GRB 171209A: Swift/UVOT Analysis of the burst
- GRB 171209A: Swift-XRT refined Analysis
- GRB 171209A: Enhanced Swift-XRT position
- Swift Trigger 796115 is probably not a GRB
- GRB 171205A: UKIRT near-IR observations
- GRB 171209A: Swift detection of a burst
- LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a
- GRB 171205A: TSHAO optical observations
- LIGO/Virgo GW170817: Chandra X-ray brightening of the counterpart 108 days since merger
- LIGO/Virgo G298048: Late-time detection of the X-ray afterglow with Chandra
- GRB 171205A: GROND observations of the optical/NIR transient
- GRB 171205A: GMG observations (2nd night)
- GRB 171205A: Host galaxy photometric properties
- GRB 171205A: CHILESCOPE optical observations