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"
32182 results found.
- GRB241113A: LCOGT (40-cm) optical counterpart detection
- GRB 241113B : detection of a long GRB by SVOM/ECLAIRs
- GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
- GRB 241113A: Swift detection of a burst with an optical counterpart
- GRB 241105A: ATCA Radio Upper Limits
- GRB 241112B: AbAO optical upper limit
- GRB 241107A: GROWTH-India telescope optical upper limit
- Fermi GRB 241112A: Global MASTER-Net observations report
- Fermi-GBM Sub-Threshold Detection of GRB 241112B
- GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
- GRB 241112B: Swift-XRT afterglow detection
- GRB 241112B: LCO optical detection of the SVOM/VT candidate
- GRB 241112B: SVOM/GRM observation
- GRB 241112B: SVOM/VT afterglow detection
- Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
- GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
- GRB 241112B: Mephisto optical upper limits
- GRB 241112B: GOTO optical upper limits
- GRB 241112B: Swift ToO observations
- GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
- GRB 241107A: INTEGRAL IBIS localization
- GRB 241112A: Fermi GBM Final Real-time Localization
- GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
- IPN triangulation of GRB 241107A (short/hard)
- GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
- GRB 241025C: VZLUSAT-2 detection
- GRB 241025A: VZLUSAT-2 detection
- GRB 241018A: cubesat Avion detection
- GRB 241111A: Fermi GBM Final Real-time Localization
- GRB 241030B: TESS detection of optical counterpart
- EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
- EP241107a: AbAO optical upper limit
- LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
- GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
- GRB 241108A: Swift-XRT observations
- EP241107A: MASTER optical observations of xray transient
- EP241107a: KAIT optical observations
- GRB 241108A: Swift ToO observations
- GRB 241030A: TESS observations
- GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
- GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
- GRB 241025A: radio detection with the VLA
- GRB 241104A: CALET Gamma-Ray Burst Monitor detection
- GRB 241107A: SVOM/GRM detection of a short burst
- GRB 241105A: EP-FXT follow-up observations
- GRB 241105A: SVOM/GRM observation
- GRB 241105a: PRIME near-infrared upper limits
- GRB 241105A: ePESSTO+ NTT optical afterglow detection
- GRB 241025A: LBT optical observations
- GRB241105A: Gemini-South Optical Afterglow Detection
- GRB 241105A: VLT/FORS2 optical afterglow rapid fading
- GRB 241105A: Swift/UVOT Detection
- EP241101a: CrAO ZTSH optical observations
- GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
- GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
- GRB 241105A: BOOTES-7 optical detection
- GRB 241030A: Mondy optical observations
- GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
- Konus-Wind detection of GRB 241105A (short with extended emission)
- Konus-Wind detection of GRB 241021A
- GRB 241105A: SVOM/VT optical afterglow observations
- GRB 241105A: Swift-XRT afterglow detection
- GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
- GRB 241104A: Swift-XRT observations
- GRB 240511A: LCO upper limits
- GRB 241104A: Fermi GBM Observation
- GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
- GRB 241105A: Swift ToO observations
- GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
- GRB 241104A: Swift ToO observations
- GRB 241104A: NOT optical non-detection
- GRB 241105A: GOTO tentative optical counterpart candidate
- Fermi GRB 241105A: Global MASTER-Net observations report
- GRB 241104A: SVOM/VT optical candidate
- GRB 241105A: Fermi GBM Final Real-time Localization
- GRB 241104A/EP241104a: Optical upper limits with Kinder observations
- GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
- GRB 241104A: SVOM/GRM observation
- EP241104a: EP detection of GRB 241104A X-ray emission
- GRB 241010A: host galaxy redshift z = 0.977
- GRB 241104A : Detection and localization by SVOM/ECLAIRs
- GRB 240821A: further radio observations with the VLA
- Fermi GRB 241104A: Global MASTER-Net observations report
- GRB 241104A: Fermi GBM Final Real-time Localization
- GRB 241030A: GRBAlpha detection
- GRB 241030A: Swift-UVOT observations of the optical prompt flare
- GRB 241030A: Rapid release of TESS data.
- GRB 241029A: GRBAlpha detection
- EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
- Swift GRB 241101A: Global MASTER-Net observations report
- GRB 241101A: FRAM-ORM optical limit
- GRB 241030A/EP241030a: TNOT observations of the optical counterpart
- EP241021a: Upper limit from Konus-Wind observations
- GRB 241101A: Swift-BAT refined analysis
- GRB 241030A: further SAO RAS optical observations
- GRB 241030A: Optical Observations via Virtual Telescope Project
- GRB 241030B: Swift-XRT refined Analysis
- GRB 241026A: SAO RAS optical observations
- GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
- EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow