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"
24603 results found.
- LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230922q: Updated Sky localization
- LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
- Title: LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
- GRB 230812B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
- LIGO/Virgo/KAGRA S230924an: Updated Sky localization
- LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
- LIGO/Virgo/KAGRA S230922g: Updated Sky localization
- LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230922q: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
- IPN triangulation of GRB 230919A (short)
- LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
- Fermi GBM Statement for Trigger 716527670/230916144
- GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
- LIGO/Virgo/KAGRA S230920al: Updated Sky localization
- LIGO/Virgo/KAGRA S230919bj: Updated Sky localization
- transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
- GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
- GRB 230919A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
- GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
- LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
- GRB 230918A (short): Glowbug gamma-ray detection
- GRB 230916B: Glowbug gamma-ray detection
- GRB 230915A: Fermi GBM observation
- GRB 230812B: Radio observations with the uGMRT
- LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
- GRB 230915B: Glowbug gamma-ray detection
- GRB 230916A: NuSTAR Discovery of Prompt Emission from a Potential GRB
- GRB 230911A: Fermi GBM Observation
- LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
- Fermi-LAT gamma-ray observations of IceCube-230914A
- GRB 230915A: Swift/BAT-GUANO detection of a burst
- LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
- Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
- IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230911A: Swift-XRT afterglow detection
- Swift Trigger 1192088 is not an astrophysical event
- GRB 230913A: Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S230914ak: Updated Sky localization
- LIGO/Virgo/KAGRA S230914ak: Identification of a GW compact binary merger candidate
- GRB 230913A: Fermi GBM Observation
- LIGO/Virgo/KAGRA S230904n: One ZTF candidate counterpart to coincident neutrino event
- Swift Trigger 1191903 is not an astrophysical event
- GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 230911A: GOTO optical counterpart candidate
- GRB 230911D: NuSTAR Detection of Prompt Emission
- GRB 230911C: Swift-XRT refined Analysis
- GRB 230911C: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S230911ae: Updated Sky localization
- GRB 230911D: Fermi GBM observation
- IPN triangulation of GRB 230911D (long)
- GRB230911C: LCOGT Optical Upper Limits
- LIGO/Virgo/KAGRA S230911ae: Identification of a GW compact binary merger candidate
- GRB 230911C: Swift/UVOT Upper Limits
- GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
- Fermi trigger No 716145795: Global MASTER-Net observations report
- GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
- GRB 230911C: Enhanced Swift-XRT position
- GRB 230911D: BALROG localization (Fermi Trigger 716111594/ GRB 230911329)
- GRB 230911C: Swift detection of a burst
- GRB 230906A: BlackGEM upper limits
- GRB 230903A: TESS observations of optical emission
- GRB 230906A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S230908b: one counterpart neutrino candidate from IceCube neutrino searches
- Glowbug gamma-ray detection GRB 230905B
- GRB 230906A: Swift/UVOT Upper Limits
- GRB 230818A: radio observation with the VLA
- GRB 230205A: LBT spectroscopy of two host galaxy candidates
- GRB 230906A: Swift-XRT observations
- GRB 230812B: Chandra late-time detection of the X-ray afterglow
- GRB 230905B: GECAM-C detection of a long burst
- LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S230819ax: Correction to PROB_BBH and PROB_TERRES probabilities
- GRB 230903A: Swift-XRT refined Analysis
- GRB 230903A: Enhanced Swift-XRT position
- GRB 230903A: VLT/X-shooter optical observations
- GRB 230903A: Swift-BAT refined analysis
- Fermi trigger No 715429986: Global MASTER-Net observations report
- GRB 230903A: Fermi GBM detection
- LIGO/Virgo/KAGRA S230904n: 1 counterpart neutrino candidate from IceCube neutrino searches
- GRB 230904B: BALROG localization (Fermi Trigger 715526984 / GRB 230904562)
- LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
- GRB 230903A: LCOGT Optical Upper Limits
- GRB 230903A: Swift detection of a burst
- LIGO/Virgo/KAGRA S230831e: Updated Sky localization
- LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
- GRB 230827B: Glowbug gamma-ray detection
- GRB 230827A: Glowbug gamma-ray detection
- GRB 230826A: Glowbug gamma-ray detection
- GRB 230827B: Swift-XRT afterglow detection
- LIGO/Virgo/KAGRA S230820bq: Updated Sky localization
- LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
- GRB 230827A: Fermi GBM Observation
- GRB 230826A: Swift-BAT refined analysis