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"32689 results found.
- LIGO/Virgo/KAGRA S230518h: Updated Sky localization
- LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
- Fermi-LAT gamma-ray observations of IceCube-230524A
- LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
- GRB 230510A: Swift-BAT refined analysis
- GRB 230525A: Fermi GBM Detection
- LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
- GRB 230523B: GRBAlpha detection
- GRB 230524A: Fermi GBM Observation
- GRB 230524A: AstroSat CZTI detection
- GRB 230524A: AGILE detection
- LIGO/Virgo/KAGRA S230521k: MASTER new OT discovery
- GRB 230523B: Name correction from GCN Circular 33859
- LIGO/Virgo/KAGRA S230521k: Additional candidates from Zwicky Transient Facility
- LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for MeerLICHT candidates: AT2023ixg and AT2023iyb
- GRB 230518B: VZLUSAT-2 detection
- Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
- IPN triangulation of GRB 230518A (short)
- GRB 230520A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
- GRB 230520B is not a GRB
- LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
- LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
- LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for Swope candidates: SSS23a, SSS23b and SSS23c
- LIGO/Virgo/KAGRA S230518h: ATLAS observations of the skymap
- LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
- GRB 230518A: Fermi GBM Observation
- LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
- GRB 230518A: Swift/BAT-GUANO detection
- LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S230518h: AstroSat CZTI non-detection and upper limits
- LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S230518h: Updated Sky localization and EM Bright Classification
- LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo/KAGRA S230518h: Identification of a GW compact binary merger candidate
- GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
- GRB 230510B: GRBAlpha detection
- Improved IPN triangulation of GRB 230512A
- GRB 230510B: Fermi GBM detection
- IPN triangulation of GRB 230511D (short)
- IPN triangulation of GRB 230512A
- GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
- GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
- GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate
- GRB 230512A: Liverpool Telescope observations
- GRB 230512A: GIT non detection of afterglow candidate
- GRB 230512A: Kitab possible afterglow candidate
- GRB 230512A: GRBAlpha detection
- GRB 230510A: GRBAlpha detection
- Fermi-LAT gamma-ray observations of IceCube-230511A
- GRB 230510A: OHP/T193 and OHP/T120 optical observations
- IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230512A: GIT optical follow-up ZTF candidates
- GRB 230512A: Fermi GBM detection
- GRB 230512A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705565670)
- GRB 230430A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 704533643)
- GRB 230512A: Tiled Swift observations
- GRB 230512A: Fermi-LAT detection
- GRB 230512A: AstroSat CZTI detection
- GRB 230510A: GIT optical upper limits
- GRB 230510A: LCOGT Optical Upper Limit
- GRB 230510A: Swift/UVOT Observations
- GRB 230510B: AstroSat CZTI detection
- GRB 230510A: Fermi GBM detection
- GRB 230510A: Gaoyazi/GOT optical upper limit
- GRB 230510B: CALET Gamma-Ray Burst Monitor detection
- GRB 230510A: CALET Gamma-Ray Burst Monitor detection
- GRB 230510A: Nanshan/NEXT optical afterglow detection
- GRB 230510B: MAXI/GSC detection
- GRB 230506B: Fermi GBM detection
- GRB 230506C: Fermi GBM detection
- GRB 230506C: T193-OHP MISTRAL tentative redshift
- GRB 230506C: SAO RAS optical observations
- GRB 230307A: JWST second-epoch observations
- IceCube-230506A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-230506A
- GRB 230506C: Swift-BAT refined analysis
- GRB 230506B: Swift-BAT refined analysis
- GRB 230506C: spectro-imaging observations of the optical afterglow with T193-OHP
- GRB 230506B: LCOGT Optical Upper Limits
- GRB 230506C: Swift/UVOT Upper Limits
- GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
- GRB 230506C: TSHAO possible afterglow candidate
- GRB 230506B: Swift/UVOT Detection
- GRB 230506B: Swift detection of a burst
- GRB 230506B: MASTER optical observations
- GRB 230506B: Swift detection of a burst
- GRB 230420A: Mondy optical afterglow detection, TSHAO, CrAO optical upper limit
- GRB 230427A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 230430A
- IPN triangulation of GRB 230430A (short)
- GRB 230420A: AROMA-N Optical Upper Limit
- GRB 230430A: Fermi GBM observation
- GRB 230430A: AstroSat CZTI detection
- GRB 230427A: NOT optical upper limit
- GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit
- GRB 230427A: Swift/UVOT Detection
- Duplicate of GCN 33369
- GRB 230427A: Gaoyazi/GOT optical upper limit
- GRB 230427A: OHP/T193 spectroscopy observations of WISEA J101316.01+481158.7