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"20951 results found.
- Fermi GBM Observations of SGR 1935+2154
- GRB 150222A: GROND optical afterglow candidate
- GRB 150222A: TNG optical observations
- Fermi GBM trigger 150223068 is not a GRB
- GRB 150222A: Mondy optical observations
- GRB 150222A: Zadko observatory - Gingin optical observations
- GRB 150222A: MASTER early optical observations
- GRB 150219A: Swift-XRT afterglow detection
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150219A: Swift ToO observations
- GRB 150213B: P60 Observations
- GRB 150213B: Swift/UVOT Detection
- GRB 150213B: RATIR Optical and NIR Observations
- GRB 150213B: AAO optical observations
- GRB 150213B: optical detection from the NOT
- GRB 150212A: Swift/UVOT Observations
- GRB 150213B: Tautenburg Afterglow Detection
- GRB 150212A: RATIR Optical and NIR Observations
- GRB 150212A: Skynet DSO14/GORT observations
- GRB 150212A: MASTER optical observations
- GRB 150210A: Swift-XRT observations
- GRB150212A: P60 Afterglow Candidate
- GRB 150211A: Swift/UVOT Upper Limits
- GRB 150211A: KAIT Optical Upper Limit
- GRB 150210A: Tiled Swift observations
- GRB 150211A: RATIR Optical and NIR Observations
- GRB 150211A: Swift-XRT observations
- GRB 150211A: MASTER early optical observations
- GRB 150101B/ Swift J123205.1-105602: Second epoch Chandra observations
- GRB 150204A: GROND observations
- GRB 150202B: Swift/XRT afterglow confirmation
- GRB 150204A: Swift/XRT afterglow confirmation
- GRB 150206A: Swift/UVOT Detection
- GRB 140206B: Continued iPTF Observations
- GRB 150206A: GROND afterglow observations
- GRB 150206B: Fermi GBM detection
- Trigger 630047: Swift detection of 1RXS J180408.9-342058
- GRB 150206B: iPTF Optical Observations
- GRB 150204A: LCOGT-Sutherland and Siding Springs observations
- GRB 150204A: Swift/UVOT Upper Limits
- GRB 150204A: Swift-XRT observations
- GRB 150204A: Swift ToO observations
- GRB 150202B: Swift XRT/UVOT observations
- GRB 150203A: RAPTOR Limits Beginning at the Gamma-Ray Emitting Interval
- GRB 150203A: Swift/UVOT Upper Limits
- GRB 150202B: Tiled Swift observations
- GRB 150202A: Swift/UVOT Upper Limits
- GRB 150203A: REM optical and NIR observations
- GRB 150203A: TAROT La Silla observatory optical observations
- GRB 150203A: GROND Upper limits
- GRB 150203A: RATIR Optical and NIR Observations
- GRB 150202A: GROND Upper limits
- GRB 150203A: P60 observations
- GRB 150203A: KAIT Optical Upper Limit
- GRB 150201A: Swift/UVOT Upper Limits
- GRB 150201A: GROND upper limits
- GRB 150120B: Khureltogot optical observations
- GRB 150128A: MASTER OT detction during inspection
- GRB 150120A: 9.8 GHz VLA upper limit
- GRB 150120A: Gemini-N imaging and host redshift
- GRB 150120A: possible AMI 15 GHz detection
- GRB 150123A: Swift/UVOT observations
- GRB 150123A: Swift-XRT observations
- GRB 150120B: Mondy optical observations
- GRB 150123A Tiled Swift observations
- GRB 150120B: RATIR Optical and NIR Observations
- GRB 150120B: FTN early optical light curve
- GRB 150120B: Swift/UVOT Upper Limits
- GRB 150120B, Optical observations
- GRB 150120B: GROND Afterglow Detection
- GRB 150120B: Additional P60 observations
- GRB 150101B: Confirmation of a fading optical counterpart
- GRB 150120A: KAIT Optical Upper Limit
- GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
- GRB 150120A: Swift/UVOT Upper Limits
- GRB 150110B: AMI 15 GHz detection of possible radio counterpart
- GRB 150101B/Swift J123205.1-105602, deep VLT observations
- GRB 150120A: Gemini-North optical imaging
- GRB 150120A: P60 optical observations
- GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
- The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
- GRB 150110C: Swift/UVOT Upper Limits
- GRB 150110C: Swift-XRT observations
- GRB 150110C Tiled Swift observations
- GRB 150110B: Swift/UVOT Upper Limits
- GRB 150101B/Swift J123205.1-105602: Chandra observations
- GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
- GRB 150101B/Swift J123205.1-105602: WSRT radio observation
- GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
- Radio upper limit on the GRB 141121A with the GMRT
- GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
- Swift detection of 4U 1700+24 (= V* V934 Her)
- GRB 150103A: MASTER optical observations
- GRB 150101B: potential host galaxy redshift by GTC
- GRB 150103A: Swift/UVOT Upper Limits
- GRB 150103A: Zadko observatory - Gingin optical observations
- Swift J123205.1-105602: Magellan candidate afterglow
- Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
- GRB 150101A: Swift/UVOT Upper Limits
- Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)