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"25476 results found.
- GRB 090510: Swift detection of a short hard burst
- GRB 090509: Swift detection of a burst
- GRB 090323: optical observations
- 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 090427: GROND observations
- GRB 090429A: ROVOR magnitude limit
- Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
- GRB 090428B: Suzaku WAM observation of the prompt emission
- GRB 090426: optical observations
- GRB 090429D: Fermi GBM detection
- GRB 090429C: Fermi GBM detection
- GRB 090427: pseudo-z= 1.48 from prompt emission spectrum
- GRB 090429B: Gemini-N further nIR observations
- 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
- GRB 090429B: Swift XRT refined analysis
- GRB 090429A: Enhanced Swift-XRT position
- Konus-Wind observation of very bright GRB 090427
- GRB 090428B: Fermi GBM detection
- GRB 090428: Fermi GBM detection
- GRB 090418A BVRcIc field calibration
- GRB 090429B: Swift-BAT refined analysis
- GRB 090429A: Swift-BAT refined analysis
- GRB 090429B: Enhanced Swift-XRT position
- GRB090429B: Gemini-N infrared IR candidate
- GRB 090426: YNAO-GMG observations
- GRB 090429B: GROND Observations
- GRB 090429B: Swift detection of a burst
- GRB 090429: Swift detection of a burst
- GRB 090423: pseudo burst at z=1 and its relation to GRB 080913
- GRB 090426: R-band limit
- GRB 090424: Continued R-band monitoring
- GRB 090423: millimeter detection
- GRB 090425: Fermi GBM detection
- GRB 090424: Suzaku WAM observation of the prompt emission
- GRB 090426: VLT spectroscopy
- GRB090426 Swift/UVOT observations
- GRB 090426: Swift-BAT refined analysis
- GRB 090426: Swift-XRT refined analysis
- Detection of bright radio afterglow of GRB 090424 with the VLA
- GRB 090426: Enhanced Swift-XRT position
- GRB 090426: inspection of SDSS images
- 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
- GRB 090424: WHT ISIS spectroscopy
- VLA radio observation of high-z GRB 090423
- GRB090424: BVRI/R-band detection after 15 hrs burst
- GRB 090424 : Lulin 1m telescope optical observations
- GRB090423: Y-band limit
- GRB 090424 Gemini-South Redshift
- GRB 090423: Y-band field calibration update/correction
- GRB 090423: Swift/BAT spectral lag results
- GRB 090424 : TAOS optical detection
- GRB 090424 optical observations
- GRB 090424: Swift-XRT refined analysis
- GRB 090424: Optical observations from 1.23m CAHA
- GRB 090423: energetic, luminosity and jet break
- Swift/UVOT observations of GRB 090424
- GRB 090424: Enhanced Swift-XRT position
- GRB 090424: Swift-BAT refined analysis
- GRB 090424: Fermi GBM Observation
- GRB 090423: Fermi GBM observation
- GRB 090422: Fermi GBM observation
- GRB 090423: Ep,i - Eiso correlation
- GRB 090424: SDSS Galaxy at the Swift position
- GRB 090424: Swift detection of a burst with an optical counterpart
- GRB 090423: Refined TNG analysis
- GRB090423: Y-band field calibration
- GRB 090423 limiting magnitudes
- GRB 090423: Near infrared observation at Okayama Observatory
- GRB 090423: GROND detection and preliminary photo-z
- GRB 090423: Swift-XRT refined analysis
- GRB090418A Rc-band photometry
- GRB090423 - Swift/UVOT upper limits.
- GRB 090423: NIR photometry and evidence for spectral break
- GRB 090422: Swift-XRT refined analysis
- GRB 090423: UKIRT data further analysis
- GRB 090423: Enhanced Swift-XRT position
- GRB 090423: Swift-BAT refined analysis
- GRB 090422: Swift/UVOT Upper Limits
- GRB 090423: Swift detection of a burst
- GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090422: Swift-BAT refined analysis
- GRB 090422: Enhanced Swift-XRT position
- GRB 090418B: Suzaku WAM observation of the prompt emission
- GRB 090422: Swift detection of a burst
- GRB 090418C: Fermi GBM Detection
- GRB 090419: Swift-XRT refined analysis
- Konus-Wind observation of GRB 090418B
- GRB 090419: Swift-BAT refined analysis
- VLA radio detection of GRB 090418
- VLA radio upper limit on GRB 090417B
- GRB 090419: Enhanced Swift-XRT position
- GRB 090418: Swift XRT refined analysis