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"35158 results found.
- GRB 170428A: MASTER-OAFA early optical observations
- GRB 170428A: Swift detection of a short burst
- GRB 170424A: LCO Observations
- Konus-Wind observation of GRB 170424A
- GRB 170419A: Swift/UVOT Upper Limits
- GRB 170424A: Tiled Swift observations
- GRB 170424A: Fermi GBM detection
- GRB 170424A: Fermi-LAT detection
- GRB 170419A: LCO Observations
- GRB 170423A: Fermi GBM detection
- Swift Trigger 748858: AbAO and TSHAO optical observations
- Fermi GBM trigger 514436208/170421123 is not a GRB
- Swift Trigger 748858: TAROT La Silla observatory optical observations
- Swift Trigger 748858: RATIR Optical and NIR Observations
- GRB 170419B, Swift-BAT refined analysis
- GRB 170419B: Zadko observatory - Gingin optical observations
- GRB 170419A: Zadko observatory - Gingin optical observations
- Fermi GBM trigger 514379207/170420463 is not a GRB
- GRB 170419A: Swift-XRT refined Analysis
- GRB 170412A CALET Gamma-Ray Burst Monitor detection
- GRB 170419B: Fermi GBM observation
- GRB 170419A: Swift-BAT refined analysis
- Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
- GRB 170419B: Swift detection of a burst
- GRB 170419A: Enhanced Swift-XRT position
- GRB 170419A: Swift detection of a burst
- Swift Trigger 748858: Zadko observatory - Gingin optical observations
- Swift Trigger 748858: a possible GRB
- GRB 170409A: TAROT Reunion observatory optical observations
- Konus-Wind observation of GRB 170409A
- GRB 170402A: AstroSat CZTI detection
- GRB 170409A: Fermi GBM Observation
- GRB 170409A: Fermi-LAT detection
- GRB 170405A: SMARTS optical/IR afterglow observations
- GRB 170403B CALET Gamma-Ray Burst Monitor detection
- GRB 170317A: SAO RAS optical observations
- GRB170405A, Swift-UVOT Detection
- GRB 170405A, Swift-BAT refined analysis
- GRB 170405A: Etelman observatory optical observations
- GRB 170405A: Swift-XRT refined Analysis
- GRB 170405A: RATIR Optical and NIR Observations
- Konus-Wind observation of GRB 170405A
- GRB 170405A: LCO FTN observations
- GRB 170405A: ISON/Terskol optical observations
- GRB 170405A: Watcher optical detection
- GRB 170405A: Redshift from OSIRIS/GTC
- GRB 170405A: TAROT Reunion observatory optical observations
- GRB 170405A: NOT optical observations
- GRB 170405A: Fermi-LAT detection
- GRB 170405A: Fermi GBM observation
- GRB 170405A: Enhanced Swift-XRT position
- GRB 170405A: Swift detection of a burst with an optical counterpart
- GRB 170402A CALET Gamma-Ray Burst Monitor detection
- GRB 170330A CALET Gamma-Ray Burst Monitor detection
- GRB 170325A: optical observations, possible OT/host detection
- Konus-Wind observation of GRB 170403A (short/hard)
- IPN Triangulation of GRB 170403A (short)
- GRB 170403A: Fermi GBM observation
- Konus-Wind observation of GRB 170330A
- IceCube-170321A: Konus-Wind upper limits
- GRB 170330A: AstroSat CZTI detection
- GRB 170330A: Swift-BAT refined analysis
- GRB 170331A: Swift-BAT refined analysis
- DOAO 1m telescope V, R, I observation of GRB 170317A
- GRB 170331A: Swift/UVOT Upper Limits
- GRB 170330A: Swift-XRT refined Analysis
- GRB 170331A: Swift-XRT refined Analysis
- GRB 170330A: Enhanced Swift-XRT position
- GRB 170331A: Enhanced Swift-XRT position
- GRB 170330A: Swift/UVOT Detection of a Fading Afterglow
- GRB 170325A: 15 GHz upper limits from AMI
- GRB 170318B: 15 GHz upper limits from AMI
- GRB 170318A: 15 GHz upper limits from AMI
- GRB 170317A: 15 GHz upper limits from AMI
- GRB 170330A: LCO Cerro Tololo observations
- Konus-Wind observation of GRB 170329A
- GRB 170329A: AstroSat CZTI detection
- IBAS trigger 7789 is not a GRB
- GRB 170331A: LCO Sutherland observations
- GRB 170331A: Prompt enhanced Swift-XRT position
- Fermi trigger 512347439/GRB 170327A: MASTER-SAAO possible OT detection
- GRB 170331A: Swift detection of a burst
- GRB 170330A: Prompt enhanced Swift-XRT position
- GRB 170330A: Swift detection of a burst
- GRB 170329A: Fermi GBM detection
- GRB 170329A: Fermi-LAT detection
- GRB 170325B: POLAR Observation
- GRB 170325A: Fermi GBM observation
- LIGO/Virgo G277583: Konus-Wind observations
- GRB 170325A, Swift-BAT detection of a short GRB
- Konus-Wind observation of GRB 170320A
- GRB 170320A: POLAR Observation
- LIGO/Virgo G277583: INTEGRAL search for an X-ray and gamma-ray counterpart
- Fermi GBM trigger 511851891/170322212 is not a GRB
- INTEGRAL SPI-ACS observation of AMON IceCube EHE 80305071 129307
- IPN Triangulation of GRB 170320A (long/intense)
- GRB 170318A: KAIT Optical Upper Limit
- GRB 170317A: Mondy optical observations
- GRB 170318B: Swift-BAT refined analysis
- GRB 170317A: POLAR observation