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"32551 results found.
- 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
- EP251122a: Global MASTER-Net observations report
- GRB 251122A/EP251122a: SVOM/C-GFT upper limit
- GRB 251122A / EP251122a: SVOM detection of a long burst
- EP251118a: Continued Optical Detection with Kinder observations
- 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 251121A: Glowbug gamma-ray detection of a likely short burst
- EP251118a: Xinglong-2.16m optical observation
- GRB 251115A: Fermi GBM Observation
- EP251118A: 1.3m DFOT optical afterglow detection
- GRB 251118A: Swift/UVOT Detection
- EP251118a / GRB 251118C: SAO RAS optical observations
- GRB 251118A: Glowbug gamma-ray detection
- GRB 251118A: Fermi GBM Observation
- GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
- EP251118a: Optical detection with Kinder observations
- GRB 251118A: GECAM-B detection
- LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
- EP251118a / GRB 251118C: SVOM/VT optical observation
- GRB 251118A: NuSTAR detection of bright prompt emission
- 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
- EP251118A / GRB 251118C : MASTER optical counterpart observations
- GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
- Konus-Wind detection of GRB 251118C (EP251118a)
- EP251118a: FTW optical and NIR observations
- GRB 251117A: Insight-HXMT/HE detection
- GRB 251119A: SVOM trigger sb25111901 is not a GRB
- EP251118a: VLT near-infrared observation
- GRB 251116D: SVOM/GRM observation of a long GRB
- EP251118a: GOTO optical afterglow detection
- EP251118a: NOT spectroscopic redshift of z = 1.216
- EP251118a: Global MASTER-Net observations report
- EP251118a: preliminary result of EP-FXT follow-up observation
- GRB 251118A: Fermi-LAT detection
- EP251118a: NOT candidate optical counterpart
- GRB 251118A: Swift ToO observations
- EP251118a: Einstein Probe detected of a fast X-ray transient
- Fermi GRB 251118B: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
- GRB 251117A: FTW Observations of Swift candidate X-ray sources
- 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 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
- LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
- 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 S251117dq: Identification of a GW compact binary merger candidate
- GRB 251116C: Swift/BAT arcminute localization of a burst
- LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
- 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
- LIGO/Virgo/KAGRA S251116en: Updated Sky localization
- GRB 251116D: Glowbug gamma-ray detection
- EP251023a: Assy AZT-20 optical observations
- EP251023a: UAFO and AbAO optical observations
- LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
- The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
- GRB 251116C: SVOM/VT optical upper limit
- GRB 251025B: further Mondy optical observations
- GRB 251111A: Mondy optical upper limit
- GRB 251116B: EP-FXT follow-up observation
- LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
- GRB 251116B: LCO optical upper limits
- GRB 251116C: LCO optical upper limits
- 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
- Fermi GRB 251115A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
- LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
- GRB 251113A: Glowbug gamma-ray detection
- GRB 251113A: AstroSat CZTI detection
- GRB 251112A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 251108C
- Konus-Wind detection of GRB 251103A
- LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
- IPN triangulation of GRB 251108C
- Fermi GRB 251114A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S251112cm: Candidates from the Zwicky Transient Facility
- LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
- LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region