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"23601 results found.
- GRB 090516C: Fermi GBM detection
- GRB 090520 Swift-BAT detection of a burst in ground analysis
- GRB 090516B: Fermi GBM detection
- GRB 090519: Swift-XRT refined analysis
- GRB 090519: GROND observation
- GRB 090519: Swift/UVOT Upper Limits
- GRB 090519, Swift-BAT refined analysis
- GRB 090519: TAROT Calern observatory optical observations
- GRB 090519: Swift detection of a burst
- GRB 090511: Fermi GBM Detection
- GRB 090514: Fermi GBM detection
- GRB 090518, Swift-BAT refined analysis
- GRB 090516, RIMOTS optical upper limits
- GRB090513: Fermi GBM detection
- GRB 090518: Swift detection of a burst
- GRB 090516: Swift-BAT refined analysis
- GRB 090516 - Zadko Telescope observations
- GRB 090516: Swift/UVOT Observations
- GRB 090516: Faulkes Telescope South optical afterglow
- GRB 090516: Swift detection of a burst
- GRB 090515: Lick Upper Limits
- GRB 090515: MMT/MMIRS NIR Upper Limit
- GRB 090515: Swift/UVOT Observations
- GRB 090515: Swift-BAT refined analysis
- GRB 090509 - Zadko Telescope observations
- GRB 090515: Gemini-N upper limit
- GRB 090515: Super-LOTIS Upper Limits
- GRB 090515: PAIRITEL Upper Limits
- GRB 090515: Swift detection of a short burst
- GRB 090510: Suzaku WAM observation of the prompt emission
- GRB 090510: GROND observations
- GRB 090510: Swift/UVOT host galaxy candidates
- GRB 090509, further Swift-BAT refined analysis
- Konus-Wind observation of GRB 090510
- AGILE detection of GRB 090510
- GRB 090510: UVOT refined analysis
- GRB 090510: NOT afterglow confirmation
- GRB 090510: Swift-BAT refined analysis
- GRB 090510: Fermi GBM detection
- GRB 090509: Swift-BAT refined analysis
- GRB 090510: Swift detection of a short hard burst
- GRB 090509: GROND afterglow candidate
- GRB 090509: Swift detection of a burst
- GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
- GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
- GRB 090428B: Suzaku WAM observation of the prompt emission
- GRB 090429D: Fermi GBM detection
- GRB 090429C: Fermi GBM detection
- GRB 090429B: Swift/UVOT Upper Limits
- GRB 090429A: Swift/UVOT Upper Limits
- GRB 090424: YNAO-GMG observations
- GRB 090429A: Swift-XRT refined analysis
- GRB 090427C: Fermi GBM detection
- GRB 090427B: Fermi GBM detection
- GRB 090426C: Fermi GBM detection
- GRB 090426B: Fermi GBM detection/observation
- Konus-Wind observation of very bright GRB 090427
- GRB 090429B: RIMOTS optical upper limits
- GRB 090429B: Swift-BAT refined analysis
- GRB 090429A: Swift-BAT refined analysis
- GRB 090426: YNAO-GMG observations
- GRB 090429B: GROND Observations
- GRB 090429B: Swift detection of a burst
- GRB 090429: Swift detection of a burst
- GRB 090424 : Multiband Optical observation from Nainital
- IPN triangulation of very bright GRB 090427
- GRB 090426: R-band limit
- GRB 090424: Continued R-band monitoring
- GRB 090423: millimeter detection
- GRB 090426: Swift/BAT spectral lag results
- GRB 090424: Suzaku WAM observation of the prompt emission
- GRB 090426: VLT spectroscopy
- GRB 090426: GROND Observations of the Optical/NIR Afterglow
- GRB 090426: Near infrared observation with ISLE at OAO
- GRB 090426: Okayama MITSuME optical observation
- GRB 090426 Keck LRIS redshift
- GRB 090426: Swift-BAT refined analysis
- GRB 090423: GROND second epoch imaging and refined SED
- GRB 090426: Swift detection of a burst with an optical counterpart
- GRB090424: R-band detection (37.5 hrs post-burst), jet break?
- GRB 090424: MASTER-Net prompt optical limit
- GRB090424: BVRI/R-band detection after 15 hrs burst
- GRB 090424: GROND Observations of the Optical/NIR Afterglow
- GRB090423: Y-band limit
- GRB 090423: Y-band field calibration update/correction
- GRB 090423: Swift/BAT spectral lag results
- GRB 090424: Liverpool Telescope observations
- GRB 090424: Optical observations from 1.23m CAHA
- GRB 090423: energetic, luminosity and jet break
- GRB 090424: MASTER-Net prompt optical observations
- GRB 090424: Swift-BAT refined analysis
- GRB 090424: Fermi GBM Observation
- GRB 090422: Fermi GBM observation
- GRB 090424: ROTSE-III Confimation of Optical Counterpart
- GRB 090424: Swift detection of a burst with an optical counterpart
- GRB 090423: Refined TNG analysis
- GRB090423: Y-band field calibration
- GRB 090423: Near infrared observation at Okayama Observatory
- GRB 090423: Deep z-band upper limit and confirmation of photo-z
- GRB 090423: TNG Amici spectrum