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"45463 results found.
- GRB 070810A: Continued Keck Imaging
- GRB 070810B: Keck spectroscopy of possible host galaxies
- GRB070810B: Swift/UVOT Upper Limits
- GRB 070810B: XRT refined analysis
- GRB 070810B, Swift-BAT refined analysis
- GRB 070809: Swift/UVOT Corrected Photometry
- Swift Trigger 287421: False trigger due to star tracker loss
- GRB 070810A: Swift-BAT refined analysis
- GRB 070810B: Xinglong TNT optical Upper Limit
- GRB070810B: Optical observations with KANATA
- A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
- GRB 070809: Swift/UVOT Upper Limits
- GRB 070810B: Swift detection of a short burst
- VLA upper limit on the short hard burst GRB 070729
- GRB 070810: Keck redshift and photometry
- No radio detection in superAGILE burst 070724B
- GRB 070809: Keck Imaging
- GRB 070810: Swift-XRT Team Refined Analysis
- GRB 070809: Swift-XRT refined analysis
- GRB 070810: enhanced Swift-XRT position
- GRB 070810: Swift/UVOT Optical Counterpart
- GRB 070810: ROTSE-III Detection of Optical Counterpart
- GRB 070810: Swift detection of a burst
- GRB 070809, Swift-BAT refined analysis
- GRB 070809: Optical Pre-imaging from Palomar
- GRB 070808: Swift/UVOT upper limits
- GRB 070809: ROTSE-III Optical Limits
- GRB 070809: Swift detection of a short burst
- GRB 070808 : Faulkes Telescope South Observations
- GCN Swift XRT update position notices and enhanced position circulars
- GRB 070808: Swift XRT refined analysis
- GRB 070808, Swift-BAT refined analysis
- GRB 070808: OPTIMA-Burst optical upper limit
- GRB 070808: Xinglong TNT optical Upper Limit
- GRB070808: Optical observations with KANATA
- GRB070808 - SDSS Pre-Burst Observations
- GRB 070808: ROTSE-III Optical Limits
- GRB 070808: Swift detection of a burst
- GRB061121A: PROMPT Observations
- GRB070805 XRT and UVOT afterglow candidate
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- GRB070612A: Radio upper limit from GMRT
- GRB 070721B: correct afterglow position
- Swift/UVOT observations of GRB070805
- GRB 070805, Swift-BAT refined analysis
- GRB 070805: Swift XRT initial analysis.
- GRB 070805: Swift/UVOT initial analysis
- GRB 070805: Swift detection of a burst
- UVOT observations of SAXJ1810.8-2609
- Swift detection of a outburst from SAX J1810.8-2609
- VLA non-detection of GRB 070721B
- GRB 070802: REM optical observations
- GRB 070724B: Swift-XRT afterglow confirmation
- GRB 070802: Swift-XRT refined analysis
- GRB070802: Swift/UVOT upper limits
- GRB 070802: Confirmation of the optical afterglow
- GRB 070802, Swift-BAT refined analysis
- GRB 070802: VLT redshift
- GRB 070802: refined Swift XRT position
- GRB 070802: V-band detection of the candidate afterglow
- GRB 070802: LCO I-band candidate
- GRB 070802: GROND J band candidate
- GRB 070802: LCO optical observations
- GRB 070802: Swift detection of a burst
- GRB 070731, Swift-BAT refined analysis
- Konus-A observation of GRB 070729
- Swift/UVOT detection of GRB070714B
- AGILE-ACS position for the SGR 1806-20 July 27 burst
- GRB 070724B: pseudo-z ~ 1.10 from prompt emission spectrum
- GRB 070729: LCO optical imaging
- VLA upper limit on short hard burst GRB 070714B
- Intense burst from SGR 1806-20 detected on July 27
- GRB070729: Swift/UVOT upper limits
- GRB 070729: Swift-XRT refined analysis
- GRB 070729, Swift-BAT refined analysis
- GRB 070729: Magellan NIR Observations
- GRB 070724B: P60 Observations
- GRB 070729: Swift detection of a short hard burst
- GRB 070724B: Swift/UVOT Upper limits
- GRB070721A: Swift/UVOT Detection of a Weak Afterglow
- GRB 070724B: Swift-XRT afterglow likely candidate
- GRB 070721A: optical observations
- GRB 070724A: further VLT observations
- GRB 070724B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 070724B
- GRB 070724B: Analysis of AGILE gamma-ray data
- GRB 070724B: Swift-XRT afterglow candidates
- GRB 070724b: First Gamma Ray Burst Localization by SuperAGILE onboard
- Four radio sources in Swift-XRT error box of GRB 070724
- GRB 070724: optical observations
- GRB070724: Host galaxy redshift
- GRB 070724: P60 and Gemini Observations
- GRB 060814 - Keck host detection and redshift
- GRB 070724: IR observations
- GRB 070724: Closer association with DSS source
- Swift/UVOT refined analysis of GRB070724
- GRB 070724: Swift-XRT Team refined analysis
- GRB 070724: Pre-Imaging Shows a Source in the XRT Error Circle
- Short-Hard GRB070714B: PROMPT Observations
- GRB 070724, Swift-BAT refined analysis of a short burst