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"
3040 results found.
- GRB 180823A: Swift-XRT refined Analysis
- GRB 180821A: Swift-XRT refined Analysis
- GRB180806A: confirmation of the X-ray afterglow
- GRB 180818B: Swift-XRT refined Analysis
- GRB 180818A: Swift-XRT refined Analysis
- Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
- GRB 180812A: Swift-XRT refined Analysis
- GRB 180809B: Swift-XRT refined Analysis
- Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
- GRB 180809B: Swift/UVOT Detection
- GRB 180809A: Swift-XRT afterglow detection
- GRB 180806A: Swift-XRT afterglow detection
- GRB 180805A: Swift-XRT refined Analysis
- GRB 180805B: Swift-XRT refined Analysis
- GRB 180728A: Swift-XRT refined Analysis
- GRB 180727A: Swift-XRT refined Analysis
- GRB 180722A: Swift-XRT observations
- GRB 180718B: Swift-XRT observations
- GRB 180718A: Swift-XRT observations
- GRB 180720C: Swift-XRT refined Analysis
- GRB 180721A: Swift-XRT refined Analysis
- GRB 180720B: Swift-XRT refined Analysis
- GRB 180715A: Swift-XRT observations
- GRB 180715A: Swift-XRT observations
- GRB 180709A: Swift-XRT refined Analysis
- GRB 180703A: Swift-XRT afterglow detection
- GRB 180705A: Swift-XRT refined Analysis
- GRB 180706A: Swift-XRT refined Analysis
- GRB 180704A: Swift-XRT refined Analysis
- GRB 180703A: Swift-XRT observations
- GRB 180630A: Swift-XRT refined Analysis
- GRB 180626A: Swift-XRT refined Analysis
- GRB 180624A: Swift-XRT refined Analysis
- GRB 180623A: Swift-XRT refined Analysis
- GRB 180613A: Afterglow confirmation and added photometry
- GRB 180620B: Swift-XRT refined Analysis
- GRB 180620A: Swift-XRT refined Analysis
- GRB 180618A: Swift-XRT refined Analysis
- GRB 180614A: Swift-XRT refined Analysis
- GRB 180613A: Possible IR afterglow
- GRB 180613A: Swift-XRT refined Analysis
- GRB 180602A: Swift-XRT refined Analysis
- GRB 180514A: Swift-XRT refined Analysis
- GRB 180512A: Swift-XRT refined Analysis
- GRB 180510B: Swift-XRT refined Analysis
- GRB 180510A: Swift-XRT refined Analysis
- Chandra observations of GW170817 reveal a fading afterglow
- Chandra observations of GW170817 260 days since merger: first statistically significant evidence for an X-ray decay
- GRB 180504A: Swift-XRT refined Analysis
- GRB 180425A: Swift-XRT refined Analysis
- GRB 180418A: Swift-XRT refined Analysis
- GRB 180409A: Swift-XRT afterglow detection
- GRB 180411A: Swift-XRT refined Analysis
- GRB 180410A: Swift-XRT refined Analysis
- GRB 180409A: Swift-XRT observations
- Chandra observations of GRB161219B 400 days after the explosion
- GRB 180404A: Swift-XRT refined Analysis
- GRB 180404B: Swift-XRT refined Analysis
- GRB 180402A: Swift-XRT refined Analysis
- GRB 180331B: Swift-XRT refined Analysis
- GRB 180331A: Swift-XRT refined Analysis
- GRB 180329B: Swift-XRT refined Analysis
- GRB 180325A: Swift-XRT refined Analysis
- GRB 180324A: Swift-XRT refined Analysis
- GRB 180316A: Swift-XRT refined Analysis
- GRB 180314B: Swift-XRT refined Analysis
- GRB 180314A: Swift-XRT refined Analysis
- GRB 180311A: Swift-XRT refined Analysis
- GRB 180305A: Swift-XRT afterglow detection
- GRB 180224A: Swift-XRT refined Analysis
- GRB 180222A: Swift-XRT refined Analysis
- Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
- Swift J1658.2-4242: Swift BAT and XRT refined analysis
- Swift J1658.2-4242 (trigger 810300): Swift-XRT position
- GRB 180210A: Swift-XRT afterglow detection
- GRB 180205A: Swift-XRT refined Analysis
- GRB 180204A: Swift-XRT refined Analysis
- GW170817/GRB170817A: Updated results from the full Chandra dataset
- LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
- Konus-Wind observation of GRB 180113A
- GRB 180115A: Swift-XRT refined Analysis
- GRB 180103A: Swift-XRT afterglow detection
- GRB 180111A: Swift-XRT refined Analysis
- GRB 180103A: Swift/UVOT Upper Limits
- GRB 180103A: Swift-XRT observations
- GRB 180102A: Swift-XRT refined Analysis
- GRB 171222A: Swift-XRT refined Analysis
- GRB 171210A: Further Swift-XRT observations
- GRB 171216A: Swift-XRT refined Analysis
- GRB 171212A: Swift-XRT refined Analysis
- GRB 171211A: Swift-XRT refined Analysis
- GRB 171210A: Swift-XRT and UVOT observations
- Swift trigger 796115 is not astrophysical
- GRB 171209A: Swift-XRT refined Analysis
- LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a
- LIGO/Virgo G298048: Late-time detection of the X-ray afterglow with Chandra
- GRB 171205A: Host galaxy photometric properties
- GRB 171205A: Swift-XRT refined Analysis
- GRB 171124A: Swift-XRT afterglow detection
- INTEGRAL pointed follow-up of IceCube-171106A