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"19549 results found.
- LIGO/Virgo G275697: Further Swift-XRT sources
- LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
- LIGO/Virgo G275404: A near-infrared transient in the error circle of AGL J1914+1043
- LIGO/Virgo G275697: CALET Observations
- LIGO/Virgo G275697: MASTER automatic follow up detection
- LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
- LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275697: Swift/BAT data search
- LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/VIRGO G275697: Fermi GBM Observations
- LIGO/Virgo G275697 ANTARES search
- LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
- LIGO/Virgo G275404 ANTARES search
- LIGO/Virgo G275404: Swift/BAT data search
- LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
- LIGO/Virgo G274296: Swift/BAT data search
- LIGO/Virgo G275404: Fermi GBM Observations
- LIGO/Virgo G274296: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G274296: MASTER new OT
- LIGO/Virgo G274296: CALET Observations
- LIGO/Virgo G274296: HAWC follow-up
- GRB 170222A: Tiled Swift observations
- GRB 170222A: Swift ToO observations
- LIGO/Virgo G274296: PIRATE Observations
- IPN Triangulation of GRB 170222A (short/hard)
- LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
- Swift Trigger 739517 is probably not a GRB
- LIGO/Virgo G274296: Asiago 1.82m Optical Observations
- LIGO/Virgo G274296: MASTER new bright possible SN detection and inspection dinamic
- LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
- LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G274296 ANTARES search
- LIGO/Virgo G274296: Optical Observation
- LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
- LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
- LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/VIRGO G274296: Fermi GBM Observations
- GRB 170214A: Swift-XRT afterglow detection
- Trigger 738728: Swift triggered on noise near NGC 4096
- GRB 170214A: Mondy optical upper limit
- GRB170214A: RATIR Optical and NIR Afterglow Confirmation
- GRB 170214A: GROND detection in all bands
- GRB 170214A: Swift/UVOT Upper Limits
- GRB170214A: RATIR Optical and NIR Observations
- GRB 170209A: GROND confirmation of MASTER afterglow
- GRB 170214A: Swift ToO observations
- GRB 170208B: IRSF upper limits
- GRB 170208A: IRSF upper limits
- GRB 170209A: Swift-XRT observations
- IPN Triangulation of GRB 170210A
- GRB 170209A: Swift ToO observations
- GRB 170208B: Swift/UVOT Upper Limits
- GRB 170208B: RATIR Optical and NIR Observations
- GRB 170208A: Swift-BAT refined analysis
- Fermi Trigger 508295323: MASTER-OAFA possible OT detection
- GRB 170208A: Swift-XRT refined Analysis
- GRB 170208B WHT nIR candidate afterglow
- GRB 170208A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 170208B
- Konus-Wind observation of GRB 170208A
- GRB 170208B: GROND observations
- GRB 170208B: NOT upper limits
- GRB 170208B: Etelman observatory optical observations
- GRB 170208B: Enhanced Swift-XRT position
- GRB 170208A: Enhanced Swift-XRT position
- GRB 170208B: Swift detection of a burst
- GRB 170208A: Swift detection of a burst
- IPN Triangulation of GRB 170207A (long/very bright)
- GRB 170206B: Swift/UVOT Upper Limits
- GRB 170206B: Swift-XRT refined Analysis
- GRB 170206B: Enhanced Swift-XRT position
- GRB 170206B: Swift detection of a burst
- GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
- GRB 170205A: NOT afterglow observations
- GRB 170205A: Enhanced Swift-XRT position
- GRB 170205A: RATIR Optical and NIR Observations
- GRB 170202A: SMARTS optical/IR afterglow observations
- GRB 170205A: Swift detection of a burst with an optical counterpart
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: Etelman Observatory optical observations
- GRB 170202A: RATIR Optical and NIR Observations
- GRB 170202A: SQUEAN Observation
- GRB 170202A: T100 observations
- GRB 170202A: Swift/UVOT Detection
- GRB 170202A: Enhanced Swift-XRT position
- GRB 170202A: NOT afterglow observations
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
- GRB 170202A: Mini-MegaTORTORA upper limits
- GRB 170202A: Swift detection of a burst with an optical afterglow
- GRB 170131A: Swift/UVOT Upper Limits
- GRB 170131A: Swift ToO observations
- GRB 170127B: Swift-BAT refined analysis
- GRB 170127C: Swift-XRT observations
- GRB 170127A: GROND Upper limits
- GRB 170124A: CALET Gamma-Ray Burst Monitor detection
- GRB 170127B: Swift/UVOT Upper Limits
- GRB 170127A: Swift/UVOT Upper Limits