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').
5468 results found.
- GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
- GRB 231020A: Fermi GBM Detection
- GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
- GRB231017A: GROWTH-India upper limits on the optical afterglow
- GRB 231018A: Fermi GBM Detection
- GRB 231017A: Fermi GBM Detection
- GRB 231017A: Swift-XRT observations
- Fermi-LAT gamma-ray observations of IceCube-231014A
- IceCube-231004A: No significant detection in HAWC
- Fermi-LAT gamma-ray observations of IceCube-231004A
- Fermi GBM Statement for Trigger 716527670/230916144
- AT 2023sva: NOT observations of the ZTF candidate afterglow
- GRB 230915A: Fermi GBM observation
- GRB 230911A: Fermi GBM Observation
- Fermi-LAT gamma-ray observations of IceCube-230914A
- GRB 230906A: optical counterpart
- GRB 230911A: Swift-XRT afterglow detection
- GRB 230913A: Fermi GBM Observation
- GRB 230911C: Swift-XRT refined Analysis
- GRB 230906A: Chandra detection of the X-ray afterglow
- GRB 230911D: Fermi GBM observation
- GRB 230911D: Fermi-LAT detection
- GRB 230906A: BlackGEM upper limits
- GRB 230906A: Swift/UVOT Upper Limits
- GRB 230906A: Swift-XRT observations
- GRB 230812B: Chandra late-time detection of the X-ray afterglow
- GRB 230903A: Swift-XRT refined Analysis
- GRB 230903A: Fermi GBM detection
- GRB 230827B: Swift-XRT afterglow detection
- GRB 230827A: Fermi GBM Observation
- GRB 230827B / GRB 230827256: Fermi GBM Observation
- GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
- GRB 230826A: Fermi GBM Observation
- GRB 230826A: Swift-XRT refined Analysis
- GRB 230822A: Fermi GBM Observation
- GRB 230812B: SAO RAS RC-500 and Zeiss-1000 observations
- GRB 20230818A: GIT optical upper limit
- Konus-Wind detection of GRB 230818A
- GRB 230818A: Fermi GBM Observation
- GRB 230812B: GIT Confirmation of SN rise
- GRB 230812B: SAO RAS Zeiss-1000 observations
- GRB 230818A: further SAO RAS Zeiss-1000 observations
- GRB 230818A: Swift-XRT refined Analysis
- GRB 230818A: SAO RAS Zeiss-1000 observations
- Fermi GRB 230818A: Global MASTER-Net observations report
- Fermi trigger No 713974668: Global MASTER-Net observations report
- GRB 230812B: SAO RAS observations, possible re-brightening
- GRB 230812B: SAO RAS optical observations
- GRB 230816A: Swift-XRT refined Analysis
- GRB 230812B: optical photometry from Konkoly
- GRB 230812B: SAO RAS optical observations
- GRB230816A: Possible host and GIT detection of optical counterpart
- GRB 230816A: SAO RAS optical observations
- GRB 230815A: Swift-XRT refined Analysis
- GRB 230812B: iTelescope optical upper limit
- GRB 230812B: continued SAO RAS optical observation
- GRB 230815A: Fermi GBM detection
- GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
- GRB 230812B: further SAO RAS optical observations
- GRB 230812B: Upper limits from a neutrino search with IceCube
- GRB 230812B: GIT optical follow-up
- GRB 230812B: rest-frame energetics from Konus-Wind observation
- GRB 230812B: SAO RAS optical observations
- GRB 230812B: Swift-XRT afterglow detection
- GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
- GRB 230812B: Improved Swift/XRT localization
- GRB 230812B: Fermi-LAT detection
- GRB 230808A: Fermi GBM Detection
- GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
- GRB 230805B: Fermi GBM observation
- GRB 230805B: Swift-XRT refined Analysis
- GRB 230805B: SAO RAS optical observations
- GRB 230802A: Fermi GBM observation
- GRB 230802A: Swift-XRT refined Analysis
- LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- Fermi-LAT gamma-ray observations of IceCube-230727A
- GRB 230728A: Fermi GBM Observation
- GRB 230728A: Swift-XRT refined Analysis
- Fermi-LAT gamma-ray observations of IceCube-230725A
- Fermi-LAT gamma-ray observations of IceCube-230724A
- GRB 230723B: Fermi GBM observation
- GRB 230723B: Swift-XRT refined Analysis
- Swift-XRT position for GRB 230723B
- GRB 230709C: Fermi GBM Detection
- GRB 230707B: Fermi GBM Observation
- IceCube-230707A: No candidates detected by Swift-XRT
- Fermi-LAT gamma-ray observations of IceCube-230708A
- Fermi-LAT gamma-ray observations of IceCube-230707B
- Fermi-LAT gamma-ray observations of IceCube-230707A
- GRB 230707A: Swift-XRT observations
- GRB 230707A: Fermi GBM Detection
- ZTF23aaoohpy/AT2023lcr : HCT follow-up observations
- LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
- GRB 230628E: Swift-XRT refined Analysis
- LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- GRB230626A: Fermi GBM Detection
- GRB 230623A: Swift-XRT observations
- INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
- ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
- GRB 230622A: Swift-XRT refined Analysis