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"
6096 results found.
- GRB071021 : CFHT Ks-band observation
- GRB 071025: I-detection, R-dropout?
- GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071020, Swift-BAT refined analysis
- GRB 071018: Swift-XRT observation
- GRB 071017 - Swift XRT observations
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071013: TLS 2nd epoch - Kornienko candidate constant
- GRB 071011: Swift-XRT refined analysis
- GRB 071011: NAYUTA Optical Observation, correction to GCN6886
- GRB 071011, Optical afterglow
- GRB 071010: Swift-XRT observation
- GRB071008: Swift-XRT observation
- GRB 071010: Keck Observations of the Afterglow
- GRB 071003: XRT refined analysis
- GRB070920A: MAGIC telescope GeV observation
- GRB 070810B: further XRT analysis
- GRB 071003: Possible rebrightening
- GRB 071003: Swift XRT position
- GRB 071003 Optical observations
- GRB 071001: Swift-XRT Team refined analysis
- GRB070925: Swift-XRT Position
- GRB 070920B: XRT observations
- GRB 070923: Galaxies within BAT localization
- INTEGRAL ToO observations of SGR1806-20
- GRB 070917: Confirmation of the X-ray afterglow
- GRB 070920, Swift-BAT refined analysis
- GRB 070917: Swift-XRT observations
- GRB 070917: R band observations
- GRB 070913: Swift-XRT detection of the possible X-ray afterglow
- GRB 070911: PAIRITEL IR Observations
- GRB 070911: Swift XRT refined analysis
- GRB 070731: Swift/UVOT Upper Limit
- IPN Localization of GRB 070821 (long, very bright)
- GRB 070810B: XRT refined analysis
- A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
- GRB 070810: Swift-XRT Team Refined Analysis
- GRB 070809: Swift-XRT refined analysis
- GRB 070805: Swift XRT initial analysis.
- GRB 070724B: Swift-XRT afterglow confirmation
- GRB 070802: Swift-XRT refined analysis
- GRB 070802: GROND J band candidate
- GRB 070729: Swift-XRT refined analysis
- GRB 070729: Magellan NIR Observations
- GRB 070724: P60 and Gemini Observations
- GRB 070724: Swift-XRT Team refined analysis
- GRB 070721A: Swift/XRT refined analysis
- GRB 070616: No Evidence for I Band Afterglow
- GRB 070714A: Swift XRT refined analysis
- GRB070714B: Swift-XRT refined analysis
- GRB 070707: Swift-XRT follow-up observations
- Swift XRT observation of GRB 070707
- GRB 070628: Swift XRT refined analysis
- GRB070621: Swift XRT refined analysis
- GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
- GRB 070616: Swift XRT refined circular
- SWIFT J195509.6+261406 (GRB 070610): further observations
- GRB 070612B: Swift-XRT refined analysis
- SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
- GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
- GRB 070610: Swift-XRT refined analysis
- GRB 070611: Swift-XRT refined analysis
- GRB 070611; Swift-XRT position
- GRB 070610; Swift-XRT position
- GRB 070529: Swift-XRT refined analysis
- GRB 070521: Swift-XRT refined analysis
- GRB 070521: Keck imaging
- GRB070521: Gemini Observations
- GROND upper limits of GRB 070521
- GRB 070520B: Swift-XRT refined analysis
- GRB 070520A: Swift-XRT refined analysis
- GRB 070518: Swift-XRT refined analysis
- RHESSI Spectrum of GRB070508
- GRB 070508: Swift-XRT refined analysis
- GRB070412: MAGIC telescope GeV observation
- GRB 070429A: Swift XRT further analysis
- GRB 070420: Swift XRT refined analysis
- GBR 070419A: Swift/XRT refined analysis
- GRB 070419B: Swift XRT refined analysis
- GRB 070419A: Optical and IR observations with KANATA
- GRB 070418: Optical and IR observations with KANATA
- GRB 070406: Swift XRT refined analysis
- GRB 070411: Swift-XRT refined analysis
- GRB 070406: Swift XRT team further analysis
- Suzaku ToO observation of SGR 1806-20
- GRB 070406: Astrometrically Refined XRT Position, Unfading Source
- GRB 070406: Gemini South Imaging and XRT analysis
- GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
- GRB 070406: SARA upper limit
- GRB 070330: Swift-XRT refined analysis
- Konus-Wind observation of GRB 070328
- GRB 070328: Swift/XRT Refined Analysis
- GRB070208: optical observations
- GRB 070318: Gemini + Magellan spectra
- GRB070318: Swift-XRT refined analysis
- GRB 070311: Swift-XRT refined analysis
- GRB 070125: Chandra X-ray Confirmation of Jet Break
- GRB 070125: X-ray light curve analysis
- GRB 070306: XRT Team Refined Analysis