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"
3046 results found.
- LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a
- LIGO/Virgo G298048: Late-time detection of the X-ray afterglow with Chandra
- GRB 171205A: Host galaxy photometric properties
- GRB 171205A: Swift-XRT refined Analysis
- GRB 171124A: Swift-XRT afterglow detection
- INTEGRAL pointed follow-up of IceCube-171106A
- GRB 171124A: Swift-XRT observations
- GRB 171123A: Swift-XRT refined Analysis
- GRB 171120A: Swift-XRT refined Analysis
- GRB 171120A: Fermi-LAT detection
- GRB 171115A: Swift-XRT refined Analysis
- IceCube-171106A: Swift Observations
- GRB 171102B: Swift-XRT refined Analysis
- GRB 171030A: Swift non-localization with BAT, XRT and UVOT
- GRB 171027A: Swift-XRT refined Analysis
- Swift Trigger 781740 is not a burst
- GRB 171020A: Swift-XRT refined Analysis
- GRB 171010B: Swift-XRT afterglow detection
- BAT trigger 778435 is not a GRB.
- GRB 171010B: Swift-XRT observations
- GRB 171010A: Swift-XRT afterglow detection
- GRB 171007A: Swift-XRT refined Analysis
- GRB 171004A: Swift-XRT refined Analysis
- GRB 171001A: Swift-XRT refined Analysis
- GRB 171001A: IRSF Observation
- Further Swift-XRT observations of IceCube 170922A
- IceCube-170922A: Swift-XRT observations
- GRB 170921A: Swift-XRT refined Analysis
- LIGO/Virgo G297595: NIR Observations following GW170814
- GRB 170912A: Swift-XRT refined Analysis
- GRB 170912B: Swift-XRT refined Analysis
- GRB 170906B: Swift/UVOT Upper Limits
- LIGO/Virgo G299232: Swift-XRT sources
- GRB 170906A: Swift-XRT refined Analysis
- GRB 170906C: Swift-XRT refined Analysis
- GRB 170903A: Swift-XRT refined Analysis
- LIGO/Virgo G298048: Chandra X-ray Update on GW170817
- LIGO/Virgo G298048: Chandra monitoring of the X-ray emission from SSS17a
- LIGO/Virgo G298048: Possible Plateau in Ks band revealed by continued Gemini-South observations
- LIGO/Virgo G298048: Continued Gemini South observations
- LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
- LIGO/Virgo G299232: Further Swift/UVOT Observations of Optical Transient SwiftJ014008.5+343403.6
- LIGO/Virgo G299232: Optical Transient Discovery by Swift/UVOT
- LIGO/Virgo G298936: HAWC follow-up
- GRB 170827A: Swift-XRT refined Analysis
- LIGO/Virgo G299232/PGWB170825.55: MASTER Global-Net OT inside NGC1343 discovery
- LIGO/Virgo G299232 : Fermi-LAT search for high-energy gamma-ray counterpart
- LIGO/Virgo G298389: HAWC follow-up
- LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
- LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
- LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 170822A: Swift-XRT refined Analysis
- LIGO/Virgo G298389 : Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G298048: Possible X-ray detection with Swift
- LIGO/Virgo G298048: optical spectral energy distribution of SSS17a
- LIGO/VIRGO G298048: Swift UVOT detection and XRT upper limits
- LIGO/Virgo G297595: Swift-XRT sources
- LIGO/Virgo G297595 : Fermi-LAT search for high-energy gamma-ray counterpart
- GRB 170813A: Swift/UVOT Upper Limits
- GRB 170813A: Swift-XRT refined Analysis
- GRB 170810A: Swift-XRT refined Analysis
- LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
- GRB 170804A: Swift-XRT refined Analysis
- Swift Trigger 766161 is not a GRB
- GRB 170803A: Swift-XRT refined Analysis
- GRB 170714A: Chandra observations
- GRB 170728A: Swift-XRT refined Analysis
- GRB 170728B: Swift-XRT refined Analysis
- GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
- GRB 170714A: Swift-XRT refined Analysis
- GRB 170711A: Swift-XRT refined Analysis
- GRB 170710B: Fermi GBM observation
- GRB 170710B: Swift-XRT and UVOT observations
- GRB 170710A: Swift-XRT refined Analysis
- GRB 170705A: Swift-XRT refined Analysis
- GRB 170629A: Swift-XRT refined Analysis
- GRB 170626A: Swift-XRT refined Analysis
- LIGO/Virgo G288732: Kiso/KWFC optical imaging of the possible Fermi/LAT counterpart
- LIGO/Virgo G288732: Swift/UVOT follow up of the possible LAT counterpart
- LIGO/Virgo G288732: Swift-XRT follow up of the putative LAT counterpart
- LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
- GRB 170607A: Swift-XRT refined Analysis
- Swift trigger 755873: Swift BAT and XRT refined analysis
- GRB 170522A: confirmation of the X-ray afterglow
- GRB 170604A: Swift-XRT refined Analysis
- GRB 170531B: Swift-XRT refined Analysis
- GRB 170531A: Swift-XRT refined Analysis
- GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
- GRB 170526A: Swift-XRT refined Analysis
- GRB 170524B: Swift-XRT observations
- GRB 170524A: Swift-XRT refined Analysis
- GRB 170522A: Swift-XRT observations
- GRB 170519A: KAIT Optical Observations
- GRB 170519A: Swift-XRT refined Analysis
- GRB 170510A: Swift-XRT afterglow detection
- GRB 170516A: Swift-XRT refined Analysis
- GRB 170510A: Swift-XRT observations
- Swift XRT observations of GRB 170424A
- LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 170428A: Swift-XRT refined Analysis