GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"15271 results found.
- GRB 251130B: AstroSat CZTI detection
- EP251130a: SAO RAS optical observations
- EP251130a: refined analysis of the EP-WXT and EP-FXT observations
- EP251130a: JinShan optical observations
- GRB 251127A: SVOM/GRM observation
- IceCube-251130A - IceCube observation of a high-energy neutrino candidate track-like event
- EP251130a: Swift-XRT counterpart detection
- EP251129a/GRB 251129A: EP-FXT follow-up observations
- GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
- GRB 251129A / EP251129a: OSN and CAHA optical follow-up
- GRB 251128A: AstroSat CZTI detection
- GRB 251128A: GECAM-B detection
- GRB 251128A: SVOM/GRM observation of a long burst
- GRB 251128A: Insight-HXMT/HE detection
- GRB 251129A: Swift ToO observations
- GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data
- GRB 251129A: SVOM detection of a burst
- GRB 251129A: SVOM detection of a burst
- GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
- GRB 251126A: OHP/T193 optical observations and tentative spectroscopic redshift
- GRB 250702B: detection of the compact radio counterpart 139 days after the burst
- GRB 251126A NUTTelA-TAO Early Measurements
- EP251124a: Pan-STARRS ri-band imaging and photometry
- GRB 251126A : MITSuME Akeno optical afterglow candidate detection
- GRB 251126A: NOT optical observations
- GRB 251126A: COLIBRÍ photometric redshift z = 3.5
- GRB 251125B: GECAM-B detection
- GRB 251126A: Kilonova-Catcher optical afterglow detection
- GRB 251126A: Nanshan/HMT optical afterglow detection
- GRB 251126A: Swift detection of a burst
- EP251124a: NOT r- and z-band optical upper limits
- GRB 251124A: Fermi GBM Localization by automated pipeline
- LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
- EP251124a: Optical upper limit with Kinder observations
- LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
- LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
- EP251124a: Einstein Probe detection of an X-ray transient
- GRB 251116C: Swift-XRT confirmation of fading
- GRB 251122A / EP251122a: EP-FXT counterpart detection
- GRB 251122A / EP251122a: WFST optical observations
- GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
- GRB 251122A/EP251122a: Additional, deeper LCO optical r band upper limit
- GRB 251122A / EP251122a: LCO optical upper limits
- GRB 251122A / EP251122a: SVOM detection of a long burst
- LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
- LIGO/Virgo/KAGRA S251112cm: SOAR spectroscopy of three TROVE TNS candidates
- GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
- GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
- GRB 251118A: GECAM-B detection
- LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
- EP251118a / GRB 251118C: SVOM/VT optical observation
- The EP-WXT trigger 01709248403 is likely a flaring star
- GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
- GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
- GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
- Konus-Wind detection of GRB 251118C (EP251118a)
- GRB 251117A: Insight-HXMT/HE detection
- GRB 251116D: SVOM/GRM observation of a long GRB
- GRB 251119A: SVOM detection of a possible burst
- EP251118a: preliminary result of EP-FXT follow-up observation
- GRB 251118A: Fermi-LAT detection
- GRB 251118A: Swift ToO observations
- LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
- GRB 251116C: SVOM/ECLAIRs refined analysis
- GRB 251116B: SVOM/ECLAIRs refined analysis
- GRB 251117A: AstroSat CZTI detection
- GRB 251114B: Insight-HXMT/HE detection
- GRB 251114B: GECAM-B detection of a short burst
- GRB 251117A: Fermi GBM observation
- GRB 251116D: Insight-HXMT/HE detection
- GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
- GRB 251117A: SVOM/GRM observation of a short burst
- GRB 251117A: Tiled Swift observations
- GRB 251117A: Fermi-LAT detection
- LIGO/Virgo/KAGRA S251112cm: Classification of reported candidates with SOAR/Goodman
- GRB 251116B: SVOM/VT optical upper limit
- LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
- GRB 251116D: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
- GRB 251116C: SVOM detection of a burst
- GRB 251116B: SVOM detection of a burst
- IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
- LIGO/Virgo/KAGRA S251112cm: AT2025adht follow-up at Maidanak observatory by GRANDMA
- GRB 251115A: Tiled Swift observations
- GRB 251115A: Fermi-LAT detection
- GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
- LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
- GRB 251113A: AstroSat CZTI detection
- Konus-Wind detection of GRB 251108C
- Konus-Wind detection of GRB 251103A
- LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
- LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
- LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
- GRB 251111A: SVOM/ECLAIRs refined analysis
- GRB 251025B: SVOM/ECLAIRs refined analysis
- GRB 251108C: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
- GRB 251111A: Swift-XRT observations