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').
14273 results found.
- X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
- X-ray transient EP240315a: Nanshan/HMT optical upper limit
- Einstein Probe detected of a fast X-ray transient EP240315a
- GRB240204A: VIRT optical upper limit
- GRB 240312A: Glowbug gamma-ray detection
- GRB 240310B: Glowbug gamma-ray detection
- GRB 240309A: MAXI/GSC detection
- GRB 231215A: further radio observations with the VLA
- GRB 240306A: Fermi GBM observation
- GRB 240229A: Glowbug gamma-ray detection
- GRB 240227A (short): Glowbug gamma-ray detection
- GRB 240229A: GRBAlpha detection
- GRB 240306A: AstroSat CZTI detection
- Fermi-LAT gamma-ray observations of IceCube-240229A
- GRB 240305C: AstroSat CZTI detection of a short burst
- GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
- Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
- GRB240218A: ATCA observation of the radio counterpart
- GRB 240225B: Swift-XRT afterglow detection
- Swift detection of Swift J151857.0-572147
- GRB 240303A: Swift detection of a burst
- GRB 240225B: Glowbug gamma-ray detection
- GRB 240225C: Glowbug gamma-ray detection
- GRB 240225A (short): Glowbug gamma-ray detection
- GRB 240229A: DDOTI Upper Limits on the Afterglow
- GRB 240218A: NOEMA upper limit
- GRB 240225B: further SAO RAS optical observations
- GRB 240225B: VLT/X-shooter redshift
- GRB 240225B : MITSuME Akeno optical afterglow candidate detection
- GRB 240225B: 3.6m DOT observation
- GRB 240225B: WINTER near-IR observations and upper limits
- GRB 240225B: SAO RAS optical observations
- GRB 240225B: Mondy afterglow observations
- GRB 240218A: CMO SAI NIR upper limit
- GRB 240225B: Nanshan/HMT optical afterglow detection
- GRB 240225B: Swift-XRT observations
- Transient EPW20240219aa: Kp-band imaging observations with NIRES
- Transient EPW20240219aa: REM optical/NIR upper limits
- GRB 240222A: ATCA radio observations
- Transient EPW20240219aa: Xinglong-2.16m optical upper limit
- Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
- Transient EPW20240219aa: 7DT Optical Upper Limits
- Transient EPW20240219aa: Mondy optical observations
- Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
- GRB 240222A: Swift-XRT refined Analysis
- GRB 240222A: Swift/UVOT Upper Limits
- GRB 240222A: REM optical and NIR early-time observations
- GRB 240222A: Swift detection of a burst
- GRB 240218A: MeerLICHT upper limits
- GRB 240216A: Glowbug gamma-ray detection
- GRB 240218A: LBT H-band detection
- GRB 240218A: VLT/X-shooter redshift of z = 6.782
- GRB 240218A: Enhanced Swift-XRT position
- GRB 240218A: REM detection of a NIR afterglow candidate
- GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
- GRB240218A: VLT/X-shooter upper limits
- GRB 240218A: Swift detection of a burst
- GRB 240213A: Glowbug gamma-ray detection
- GRB 240128A: Further Swift-XRT observations
- GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
- IPN triangulation of GRB 240205A (short)
- Fermi-LAT gamma-ray observations of IceCube-240204A
- GRB 240205B: PRIME near infrared detection
- GRB 240205A (short): Glowbug gamma-ray detection
- GRB240204A: Swift/UVOT Upper Limits
- GRB 240205B: VLT/X-shooter redshift
- GRB 240205B: ATCA detection of radio counterpart
- GRB 240205B: REM detection of the optical/NIR afterglow
- GRB 240204A : OHP/T193/T120 optical afterglow fading detection
- GRB 240204A: Swift-BAT refined analysis
- GRB 240205B: Skynet Optical Afterglow Observations
- Fermi trigger No 728749569: Global MASTER-Net observations report
- GRB 240204a: Liverpool Telescope optical afterglow detection
- GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
- GRB 240204A: Montarrenti Observatory optical observations
- GRB 240204A: Enhanced Swift-XRT position
- GRB 240204A: Mondy optical afterglow candidate
- GRB 240204A: Swift detection of a burst
- IPN triangulation of GRB 240124B
- GRB 240128A: Glowbug gamma-ray detection
- GRB 240122A: ATCA detection of radio counterpart
- GRB240122A: PRIME near infrared detection
- GRB 240123A: Glowbug gamma-ray detection
- GRB 240125A (short): Glowbug gamma-ray detection
- IPN triangulation of GRB 240123C (short)
- Fermi-LAT gamma-ray observations of IceCube-240123A
- GRB 240123A: further SAO RAS optical observations
- GRB 240123A: SAO RAS optical observations
- GRB 240123A : MITSuME Akeno optical afterglow candidate detection
- GRB 240123A: Enhanced Swift-XRT position
- GRB 240122A: Swift/UVOT Upper Limits
- GRB 240118A: Swift/UVOT Upper Limits
- GRB 240122B: Glowbug gamma-ray detection
- GRB 240123A: Mondy optical afterglow observations
- GRB 240123A: Swift detection of a burst with a possible optical counterpart
- GRB 240122A: Swift-XRT afterglow detection
- IPN triangulation of GRB 240119A (short)
- GRB 240118A: Mondy optical observations
- GRB 240118A: Swift-XRT afterglow detection