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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"- LIGO/Virgo/KAGRA S231118an: Updated Sky localization and EM Bright Classification
- GRB 231124A: CALET Gamma-Ray Burst Monitor detection
- GRB 231115A: XMM-Newton observation
- GRB 231124A: Fermi GBM Final Real-time Localization
- GRB 231123A: AstroSat CZTI detection
- GRB 231117A: Mondy optical observations
- GRB 231123C: Fermi GBM Final Real-time Localization
- GRB 231123B: Fermi GBM Final Real-time Localization
- Fermi trigger No 722400249: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231123cg: Identification of a GW compact binary merger candidate
- GRB 231118A: REM optical afterglow detection
- GRB 231122B: AstroSat CZTI detection
- GRB 231122B: CALET Gamma-Ray Burst Monitor detection
- GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
- GRB 231117A: Chandra afterglow detection
- GRB 231123A: Fermi GBM Final Real-time Localization
- GRB 231122B: Glowbug gamma-ray detection
- GRB 231117A: Continued GTC Observations
- Fermi trigger No 722349867: Global MASTER-Net observations report
- GRB 231122A: GECAM detection
- GRB 231122B: GECAM detection
- GRB 231122A: Fermi GBM Final Real-time Localization
- GRB 231118A: ATCA detection of radio counterpart
- GRB 231117A: Swift/UVOT late time observations
- GRB 231117A: GTC Near-Infrared Observations
- GRB 231117A: Swift-BAT refined analysis
- GRB 231118A: GRBAlpha detection
- LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
- GRB 231118A: VZLUSAT-2 detection
- GRB 231117A: AMI-LA radio observations
- GRB 231118A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 231020A
- GRB 231117A: LDT Confirmation of Optical Fading
- GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
- GRB 231118B: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A: CALET Gamma-Ray Burst Monitor detection
- 231118A: Swift-UVOT Detection
- GRB231117A: Swift-UVOT detection
- GRB 231117A : MITSuME Akeno optical afterglow candidate detection
- GRB 231118B: Fermi GBM observation
- GRB 231118A: Fermi GBM observation
- LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
- GRB 231120A: Fermi GBM Final Real-time Localization
- GRB 231117A: Swift-XRT refined Analysis
- GRB 231118A: Swift-XRT refined Analysis
- GRB 231118A: MeerLICHT afterglow detection
- LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
- GRB 231117A: OHP/T120 optical observations
- GRB 231118A: VLT/X-shooter redshift
- Fermi trigger No 722039659: Global MASTER-Net observations report
- GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
- LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
- GRB 231117A: MAAO 0.7-m telescope optical upper limit
- GRB 231117A: AKO Follow-Up Observation
- GRB 231117A: GECAM-C detection
- GRB 231118A: AstroSat CZTI detection
- GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
- GRB 231117A: 10 GHz VLA detection
- GRB 231118A: Las Cumbres optical detection
- GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
- GRB 231118B: Fermi GBM Final Real-time Localization
- GRB 231118A: LCOGT Optical Observations
- GRB 231118A: MASTER OT observation
- GRB 231118A: Continued Skynet Observations
- Swift GRB231118.72: Global MASTER-Net observations report
- GRB 231118A: Enhanced Swift-XRT position
- GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
- GRB 231118A: Swift-XRT position
- GRB 231118A: Skynet Optical Afterglow Discovery
- GRB 231117A: SOAR/Goodman imaging of the afterglow
- GRB 231118A: Swift detection of a burst
- GRB 231118A: Fermi GBM Final Real-time Localization
- GRB 231117A: Lowell Discovery Telescope Observations
- GRB 231117A: ePESSTO+ host galaxy redshift confirmation
- GRB 231117A: ATCA detection of a radio counterpart
- LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
- GRB 231117A: GRBAlpha detection
- LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
- GRB 231117A: Keck spectroscopy of afterglow candidate
- GRB 231115A: Wendelstein Optical/Infrared Observations
- GRB 231115A: JinShan optical upper limits
- LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
- GRB 231117A: GIT optical follow-up
- GRB 231117A: LT observations consistent with fading
- GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
- GRB 231117A: REM optical and NIR early-time observations
- GRB231117A: AGILE/MCAL analysis
- GRB 231117A: AKO Optical Upper Limit
- GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
- Swift GRB 231117A: Global MASTER-Net observations report
- GRB 231117A (short): Glowbug gamma-ray detection
- GRB 231117A: ATLAS non-detection of an optical counterpart
- Konus-Wind detection of GRB 231117A (short/hard)
- GRB 231115A : OHP/T120 optical upper limit