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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"8296 results found.
- GRB 140818B: Swift detection of a burst
- Swift detection of SAX J1712.6-3739
- GRB 140818A Tiled Swift observations
- GRB 140817A: Swift detection of a burst
- GRB 140808A / PTFeag: VLA K-band observations
- GRB 140815A: GROND afterglow candidate
- Swift Trigger 609694 is probably not an astrophysical source
- Swift trigger 609139 is probably 4U 1850-03
- Swift observations of possible GRB 140809A candidate
- GRB 140808A: Swift/UVOT Upper Limits
- GRB 140808A: Redshift from the 10.4m GTC telescope
- GRB 140808A: Swift-XRT observations
- GRB 140808A: optical afterglow candidate iPTF14eag
- GRB 140801A: Swift/UVOT Upper Limits
- GRB 140730A: Swift detection of a burst
- Swift Trigger 607506 is probably noise
- GRB 140729A Tiled Swift observations
- Trigger 607399: Swift detection of SGR1806-20
- GRB 140723A: LCO-Sutherland optical candidate retraction
- Konus-Wind observation of GRB 140723A
- GRB 140723A: LCO-Sutherland optical candidate
- GRB 140723A Tiled Swift observations
- GRB 140716A: Confirmation of the Swift-XRT afterglow
- GRB 140716A: GROND confirmation of the afterglow
- GRB 140719A: FTS observations
- GRB 140719A: GROND Afterglow candidate
- GRB 140719A: Swift detection of a burst
- GRB 140716A: Swift/UVOT Upper Limits
- GRB 140716A: GROND afterglow candidate
- GRB 140716A: Swift-XRT detection of an afterglow candidate
- GRB 140716A: A Fermi GBM Detection
- GRB 140713A: Swift detection of a burst
- GRB 140709A: Continued RATIR Optical and NIR Observations
- GRB 140710A: P60 Confirmation of Afterglow
- GRB 140710A: GROND Detection of NIR Afterglow Candidate
- GRB 140709A: 10.4m GTC optical decay
- GRB 140710A: Swift detection of a burst
- GRB 140709A: BOOTES-2 and OSN optical observations
- GRB 140709B: Swift detection of a burst
- GRB 140709A: Swift detection of a burst
- GRB 140706A: Swift detection of a burst with an optical counterpart
- GRB 140705A: Swift detection of a short burst
- GRB 140703A: Fermi GBM detection
- GRB 140703A: Swift detection of a burst
- Fermi 425667201: optical counterpart search
- GRB 140629A: Swift detection of a burst with an optical counterpart
- GRB 140628A: Swift detection of a burst
- Swift Trigger 602668 is probably not an astrophysical source
- GRB 140626A: GROND Afterglow Candidate
- GRB 140626A: Swift detection of a burst
- GRB 140623A: Swift-XRT and UVOT observations
- Fermi 425193729 / iPTF14cyb: Discovery of optical afterglow
- GRB 140622A: Swift detection of a short burst
- Fermi 424934131 / iPTF14cva: Discovery and Redshift of Optical Afterglow
- GRB 140614C: 1.23m CAHA (+EDIPO) observations
- GRB 140614B: Swift detection of a burst
- GRB 140614A: GROND afterglow candidate
- GRB 140614A: Swift detection of a burst
- GRB 140606B: Swift XRT refined analysis
- Fermi 423717114: Additional P48 and P60 observations
- Fermi423717114: iPTF optical transient candidates
- GRB 140606A: Swift detection of a short hard burst
- GRB 140523A: further Swift-XRT observations
- GRB 140408A: Withdrawal of afterglow candidate
- GRB 140523A: NOT observation
- IPN Triangulation of GRB 140523A
- Swift trigger 599860 probably not real
- GRB 140523A: possible X-ray afterglow candidate from tiled Swift/XRT observations
- GRB 140523A Tiled Swift observations
- GRB 140518A: Skynet GORT Detections of the Optical Afterglow
- GRB 140518A: KAIT optical candidate
- GRB 140518A: Swift detection of a burst
- GRB 140516A: Swift detection of a short burst
- GRB 140515A: Swift detection of a burst
- GRB 140508A: VLA detection
- GRB 140512A: Swift detection of a burst with an optical counterpart
- GRB 140508A: HCT spectroscopy
- VHE gamma-ray observations by MAGIC of SWIFT Trigger 596958
- GRB 140508A: Swift-XRT observations
- GRB 140508A: WHT spectroscopy
- GRB 140509A: Swift detection of a burst with an optical counterpart
- GRB 140508A: NOT photometry and spectroscopy
- GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
- GRB 140508A: iPTF optical transient candidate
- GRB 140502A: ISON-NM early optical limit
- GRB 140506A: Swift detection of a burst with an optical counterpart
- Swift Trigger 597860 is probably not a GRB
- GRB 140502A: Swift detection of a burst
- GRB140430A: Swift detection of a burst with an optical counterpart
- GRB 140428A: Keck redshift estimate
- GRB 140428A: Keck detection of a red optical afterglow candidate
- GRB 140423A: RATIR Optical and NIR Observations
- GRB 140423A: Swift/UVOT detection of a possible counterpart
- GRB 140423A optical observations with pODI/WIYN at KPNO
- GRB 140423A: optical afterglow candidate
- GRB 140419A: Refined NOT photometry
- GRB 140419A: Continued RATIR Optical and NIR Observations
- Swift Trigger 596641 is not a GRB
- GRB 140419A: ROTSE-III Detection of Optical Counterpart
- GRB 140419A (Swift trigger 596426) : KAIT optical candidate