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"44622 results found.
- Faulkes Telescope South observations of GRB 071001
- GRB 071001: Swift detection of a burst
- VLA observation of GRB 070923
- Disregard the Swift-XRT Notices today
- GRB 070911, SMARTS optical/IR afterglow observations
- GRB070925: Swift-XRT Afterglow confirmation
- GRB 070925: Gemini South Imaging
- GRB070925: Swift-XRT Position
- Update on Swift Status
- GRB 070920B: ROTSE-III Early Optical Limits
- GRB 070925: a long GRB detected by INTEGRAL
- Recent SGR1806-20 Activity
- GRB 070923, Swift-BAT refined analysis
- GRB 070920B: XRT observations
- GRB 070923: Galaxies within BAT localization
- GRB 070923: Swift detection of a short hard burst
- GRB 070917: Suzaku/WAM observation of the prompt emission
- GRB 070920B: TAROT La Silla observatory optical observations
- INTEGRAL ToO observations of SGR1806-20
- GRB 070920b, SMARTS optical observation
- GRB 070917: Confirmation of the X-ray afterglow
- GRB 070920b: LCO optical observations
- GRB 070920B, Swift-BAT refined analysis
- GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
- GRB 070920B: NOT optical observations
- GRB 070920B: Swift detection of a burst
- GRB 070920, Swift-BAT refined analysis
- GRB 070920: TAROT Calern observatory optical observations
- GRB 070920: Swift detection of a burst
- SGR1806-20: Swift-BAT detection of enhanced activity
- GRB070917: Confirmation of optical afterglow
- GRB920925C: search for host galaxy
- GRB070917: optical observations
- GRB 070917: P60 Observations
- GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
- Konus-Wind observation of GRB 070917
- Swift Status and XRT Calibration Uncertainties
- GRB 070917: Swift-XRT observations
- GRB 070917: KAIT optical limits
- GRB 070917: MITSuME Akeno Ic upper limit
- GRB 070917: R band observations
- GRB 070917, Swift-BAT refined analysis
- GRB 070917: Swift detection of a bright burst
- GRB 070911: Suzaku WAM observation of the prompt emission
- GRB 070913: Swift-XRT detection of the possible X-ray afterglow
- GRB 070809: The Swift evidence for the SHB nature of this burst
- GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
- GRB 070913: Swift-BAT refined analysis
- GRB 070913: Corrected BAT position
- GRB 070913: SMARTS optical/IR observations
- GRB 070913: TAROT La Silla observatory optical observations
- GRB 070913: Swift detection of a burst
- Swift-BAT Notices back to autonomous real-time distribution
- GRB 070911: PAIRITEL IR Observations
- GRB 070911: Swift XRT refined analysis
- GRB 070911, Swift-BAT refined analysis
- GRB 070911: Swift detection of a burst
- IPN search for a GRB associated with TAROT transient on August 31
- Intense burst from SGR 1806-20 detected on September 7
- GRB 070809: Confirmation of optical transient
- Observations of possible TAROT GRB transient near IC 4779
- Candidate Orphan GRB Optical Transient in IC 4779
- GRB 070810b: Image Subtraction of Multiple Keck Observations
- Las Campanas observations of possible TAROT GRB transient near IC
- Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
- Konus-Wind observation of GRB 070824
- GRB 070824 - Combined SuperAGILE/IPN Localization
- Konus-Wind observation of very bright GRB 070821
- GRB 070731: Swift/UVOT Upper Limit
- IPN Localization of GRB 070821 (long, very bright)
- GRB 070805: UVOT afterglow candidate retraction
- GRB070810b: optical candidate
- GRB 070810A: ROTSE-III Refined Analysis
- Swift observatory off line
- GRB 061110A: redshift confirmed
- GRB 070810B : Faulkes Telescope South Observations
- 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 070810: MASTER optical observation
- GRB 070809: Swift/UVOT Corrected Photometry
- Swift Alert 070810.8: MASTER optical observation
- 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