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"2409 results found.
- EP251122a: refined analysis of the EP-WXT and EP-FXT observations
- 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
- EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
- GRB 251122A/EP251122a: SVOM/C-GFT upper limit
- 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
- GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
- EP-WXT trigger 01709248403: confirmation of a stellar flare by SVOM/VT
- LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
- EP251118a / GRB 251118C: SVOM/VT optical observation
- EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
- GRB 251116C: NOT optical observations
- 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
- GRB 251117A: Insight-HXMT/HE detection
- GRB 251119A: SVOM trigger sb25111901 is not a GRB
- GRB 251116D: SVOM/GRM observation of a long GRB
- GRB 251119A: SVOM detection of a possible burst
- GRB 251116C: SVOM/ECLAIRs refined analysis
- GRB 251116B: SVOM/ECLAIRs refined analysis
- GRB 251117A: AstroSat CZTI detection
- 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 251116C: Swift/BAT arcminute localization of a burst
- GRB 251116B: SVOM/VT optical upper limit
- GRB 251116C: Swift-XRT observations
- GRB 251116C: SVOM/VT optical upper limit
- GRB 251116B: EP-FXT follow-up observation
- GRB 251116B: LCO optical upper limits
- GRB 251116C: LCO optical upper limits
- SVOM GRB251116C: Global MASTER-Net observations report
- GRB 251116C: SVOM detection of a burst
- GRB 251116B: SVOM detection of a burst
- GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
- Konus-Wind detection of GRB 251103A
- GRB 251111A: SVOM/ECLAIRs refined analysis
- GRB 251025B: SVOM/ECLAIRs refined analysis
- GRB251111A: 1.3m DFOT optical upper limit
- GRB 251106B: Glowbug gamma-ray detection of a likely short burst
- GRB 251111A: Swift-XRT afterglow detection
- GRB 251111A: SVOM/VT optical observations with X-band data
- SVOM GRB251111.42: Global MASTER-Net observations report
- GRB 251111A: Swift-XRT observations
- SVOM GRB251111.22: Global MASTER-Net observations report
- GRB 251111A: EP-FXT counterpart detection
- GRB 251111A: SVOM/VT optical observations with VHF data
- GRB 251111A: KAIT optical upper limit
- GRB 251111A: LCO optical observation
- GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
- GRB 251111A: SVOM detection of a soft burst
- GRB 251106A: Swift/UVOT Upper Limits
- GRB 251105B: Insight-HXMT/HE detection
- GRB 251106B: Insight-HXMT detection
- SVOM GRB251108.54: Global MASTER-Net observations report
- GRB 251102B: SVOM/GRM observation
- SVOM GRB251106.83: Global MASTER-Net observations report
- IPN triangulation of GRB 251105B (possible sGRB with EE)
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
- GRB 251106B: SVOM/GRM observation of a short burst
- GRB 251106A: Swift-XRT afterglow detection
- GRB 251106A: Kilonova-Catcher optical upper limit
- Fermi GBM Sub-Threshold Detection of GRB 251106A
- GRB 251106A: Swift/BAT arcminute localization of a burst
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
- GRB 251106A: MASTER optical observations
- GRB 251106A: SVOM detection of a burst
- GRB 251016A: TERI Gamma-ray detection of a short burst
- GRB 250920C: TERI Gamma-ray detection
- GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
- GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
- Fermi GBM Sub-Threshold Detection of GRB 251105B
- GRB 251105B: SVOM/GRM observation of a possible short burst with extended emission
- GRB 251104A: SVOM detection of a burst
- GRB 251028A: Insight-HXMT/HE detection
- GRB 251103A: WFST optical observations
- GRB 251103A: Xinglong 2.16m optical detection
- GRB 251103A: Insight-HXMT detection
- GRB 251013C: 7DT detection and Medium-band SED of Afterglow
- GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 251103A: Kilonova-Catcher optical afterglow detection
- GRB 251103A: Swift/UVOT Detection
- GRB 251103A: Fermi GBM Observation
- GRB 251103A: SVOM/GRM observation
- GRB 251103A: Swift-XRT afterglow detection
- GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
- GRB 251103A: LCO optical observation
- GRB 251026A: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical counterpart
- GRB 251103A: BOOTES-2/TELMA optical afterglow
- GRB 251103A: LCO optical afterglow detection
- GRB 251103A: SVOM detection of a bright burst
- Konus-Wind detection of GRB 251028A
- GRB 251025C: SVOM/GRM observation
- GRB 251028A: GECAM-B detection