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').
17989 results found.
- GRB 241030B: Montarrenti Observatory optical upper limit
- EP241026b: Liverpool Telescope optical follow-up
- GRB 241030A: SAO RAS optical observations
- EP241021a: AMI-LA radio detection
- GRB 241030B : GIT optical upper limits
- GRB 241030B: LCOGT Optical Upper Limits
- GRB 241030A: Swift-BAT refined analysis
- GRB 241029A: COLIBRI Detection of the Optical Counterpart
- GRB 241030B: Swift/UVOT Detection
- GRB 241029A: LCO optical detection
- GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
- GRB 241030B : MITSuME Akeno optical upper limits
- GRB 241030A: COLIBRI Continuing Detection of the Afterglow
- GRB 241030B: SVOM/VT optical afterglow observations
- GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
- EP241030a: EP detection of GRB 241030A X-ray Afterglow
- GRB 241030B: BTA observations
- GRB 241029A: SVOM/VT optical afterglow observations
- GRB 241030B: Enhanced Swift-XRT position
- GRB241030B: GRANDMA/TAROT Upper Limit
- GRB 241030B: SAO RAS optical observations
- GRB 241030B: AKO Optical Afterglow Detection
- GRB 241030B: Nanshan/HMT optical afterglow detection
- Konus-Wind detection of GRB 241030A
- GRB 241030B: Swift detection of a burst
- GRB 240912A: radio detection with the VLA
- GRB 241030A: AKO Optical Afterglow Detection
- GRB 241030A: Swift/UVOT Detection
- GRB 241030A: SVOM/C-GFT optical observations
- GRB 241026A: LBT optical observations
- EP241021a: Optical rebrightening observations with Mephisto
- GRB 241030A: Multiband optical detection with Mephisto
- GRB 241030A: SVOM/VT optical afterglow observations
- GRB 241030A : MITSuME Akeno optical afterglow detection
- GRB 241030A: Enhanced Swift-XRT position
- GRB 241029A: GROWTH-India Telescope optical follow up
- GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
- GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
- GRB 241030A: Swift detection of a burst with a bright optical counterpart
- GRB 241029A: SAO RAS optical observations
- GRB 241026A: SAO RAS optical observations
- EP241021a: SAO RAS observations of rebrightening
- GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
- MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
- GRB 241026A: Swift/UVOT Upper Limits
- GRB 241029A: AKO Optical Afterglow Detection
- EP241021a: continued SOAR observations confirm optical rebrightening
- GRB 241029A: Xinglong-2.16m optical afterglow confirmation
- GRB 241029A: Mephisto observations
- EP 241026b: LBT possible optical counterpart (brightening source)
- GRB 241029A: TRT optical afterglow candidate detection
- GRB 241026A: the 100th GRB detected by GRBAlpha
- GRB 241026A: TNOT optical counterpart detection
- Konus-Wind detection of GRB 241025A
- GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
- GRB 241025A: further SAO RAS optical observations
- GRB 241026A: BTA and Zeiss-1000 optical observations
- GRB 241026A: SVOM/GRM observation
- EP241026B: GROWTH-India Telescope optical upper limit
- GRB 241025A: Swift/UVOT Detection
- GRB 241026A: GROWTH-India Telescope optical observations
- GRB 241026A: J-band observations with WINTER
- GRB 241025A: SAO RAS optical observations
- GRB 241026A: Las Cumbres optical detection
- GRB 241025A: Mondy optical observations
- EP241021a: SOAR observations of the optical counterpart
- EP241021a: further SAO RAS optical observations
- EP 241026b: LBT optical observations
- EP241021a: e-MERLIN radio observation
- GRB 241026A: Enhanced Swift-XRT position
- EP241026b: EP detection of a fast X-ray transient
- GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
- GRB 241026A: SAO RAS observations of possible optical afterglow
- GRB 241026A: Swift detection of a burst
- GRB241025A: 1.3m DFOT optical afterglow detection
- EP241021a: optical follow-up observations with Xinglong Observatory
- GRB 241025A: GROWTH-India Telescope optical observations
- GRB 241025A: COLIBRÍ Detection of the Afterglow
- GRB 241025C: Fermi GBM Detection
- IPN triangulation of GRB 241022A (short/hard)
- LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
- GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
- GRB 241025A : SVOM/VT optical afterglow observations
- EP241021a: Liverpool Telescope optical follow-up observations
- GRB 241025A: Enhanced Swift-XRT position
- GRB 241025A: DDOTI Afterglow detection
- GRB 241025A: TRT optical afterglow observation
- GRB 241025A: Swift detection of a burst with an optical counterpart
- EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
- GRB 241001A: ATCA radio observations
- GRB 241010A: VIRT Optical Upper Limit
- EP241021a: SAO RAS optical observations
- EP241021a: KAIT optical observations
- EP241021a: EP-FXT follow-up observation update
- EP241021a: 1.3m DFOT Optical observations
- EP241021a: Optical upper limits with Kinder observations
- EP241021a: TRT optical observations
- GRB 241018A: SVOM/C-GFT optical observations
- EP241021a: NOT likely optical counterpart
- GRB241017A: 1.3m DFOT optical upper limit