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"
3050 results found.
- GRB 150626A: Swift-XRT refined Analysis
- GRB 150622A: Swift-XRT observations
- GRB 150616A: Swift-XRT refined Analysis
- GRB 150615A: Swift-XRT refined Analysis
- GRB 150608A: Swift-XRT follow-up observations
- GRB 150608A: Swift-XRT afterglow detection
- GRB 150607A: Swift-XRT refined Analysis
- Swift trigger 642453 is not an astrophysical source
- GRB 150530B: Swift-XRT observations
- GRB 150530A: Swift-XRT refined Analysis
- GRB 150513A: Swift-XRT observations
- GRB 150527A: Swift-XRT refined Analysis
- GRB 150523A Swift-XRT afterglow detection
- GRB 150518A: Swift-XRT follow-up observations
- GRB 150518A: Swift-XRT afterglow detection
- GRB 150514A: Further Swift observations
- GRB 150514A: Swift-XRT afterglow detection
- Confirmation that Swift Trigger 639636 is not astrophysical
- GRB 150430A: Swift-XRT refined Analysis
- GRB 150428B: IRSF NIR upper limits
- GRB 150428B: Swift/UVOT Upper Limits
- GRB 150428C: Swift-XRT observations
- GRB 150428B: Swift-XRT refined Analysis
- GRB 150428A: Swift-XRT refined Analysis
- GRB 150424A: Swift-XRT refined Analysis
- GRB 150423A: Swift-XRT refined Analysis
- GRB 150423A: GROND afterglow candidate
- GRB150418A: Swift/UVOT did not detect a new source
- Further Swift XRT observations of GRB 150418A
- GRB 150413A: Swift-XRT observations
- GRB 150418A: Swift-XRT observations
- Confirmation that Swift trigger 638217 is not an astrophysical source
- Swift GRB150402A: further XRT observations
- GRB 150407A: Swift-XRT observations
- GRB 150403A: Swift-XRT refined Analysis
- GRB 150402A: results of Swift observations
- GRB 150323B: Swift-XRT afterglow detection
- GRB 150323C: Nishi-Harima NIR Observations
- GRB 150323B: Swift-XRT observations
- GRB 150323C: Swift-XRT refined Analysis
- GRB 150323A: Swift-XRT refined Analysis
- GRB 150318A: Swift-XRT refined Analysis
- GRB 150317A: Swift-XRT refined Analysis
- GRB 150314A: Swift-XRT refined Analysis
- GRB 150309A: Swift-XRT refined Analysis
- Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
- Further UVOT Observations of Swift J0045.2+4151
- Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
- GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
- GRB 150302A: Swift-XRT refined Analysis
- GRB 150301B: Swift-XRT refined Analysis
- GRB 150301A: Swift-XRT refined Analysis
- GRB 150301C : (Swift trigger 633105) Swift observations
- GRB 150220A: Swift-XRT observations
- GRB 150222A: Swift-XRT refined Analysis
- GRB 150219A: Swift-XRT afterglow detection
- GRB 150213B: Swift-XRT refined Analysis
- GRB 150212A: Swift-XRT refined Analysis
- GRB 150210A: Swift-XRT observations
- GRB 150211A: Swift-XRT refined Analysis
- GRB 150101B/ Swift J123205.1-105602: Second epoch Chandra observations
- GRB 150202B: Swift/XRT afterglow confirmation
- GRB 150204A: Swift/XRT afterglow confirmation
- GRB 150206A: Swift-XRT refined Analysis
- GRB 150204A: Swift-XRT observations
- GRB 150202B: Swift XRT/UVOT observations
- Swift Trigger 629693 was a noise event
- GRB 150203A: Swift-XRT refined Analysis
- GRB 150202A: Swift-XRT refined Analysis
- GRB 150201A: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 150126A reveals its ultra-long nature
- GRB 150123A: Swift-XRT observations
- GRB 150120A: Swift-XRT refined Analysis
- GRB 150120B: Swift-XRT refined Analysis
- GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
- GRB 150110C: Swift-XRT observations
- GRB 150110B: Swift-XRT refined Analysis
- GRB 150101B/Swift J123205.1-105602: Chandra observations
- GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
- GRB 150103A: Swift-XRT refined Analysis
- GRB 150103A: Swift/UVOT Upper Limits
- Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
- GRB 150101A: Swift-XRT refined Analysis
- Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
- GRB 141229A: Swift-XRT observations
- GRB 141225A: Swift-XRT refined Analysis
- Swift XRT and UVOT observations of GRB141222A
- GRB 141215A: further Swift-XRT observations and afterglow detection
- GRB 141221A: Swift-XRT refined Analysis
- GRB 141220A: Swift-XRT refined Analysis
- GRB 141215A: Swift-XRT observations
- GRB 141212B: Swift-XRT refined Analysis
- GRB 141212A: Swift-XRT refined Analysis
- GRB 141207A: Swift-XRT afterglow candidate detection
- GRB 141207A: Swift-XRT observations
- GRB 141205A: XRT observations
- GRB 141202A: Swift/UVOT Detection of a Variable Source Near the IPN Error Box
- GRB 141202A: Swift XRT observations
- GRB 141130A: Swift-XRT refined Analysis
- GRB 141121A: Swift-XRT refined Analysis