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"14247 results found.
- GRB050421: Radio Observations
- GRB050421: Radio Observations
- GRB050421
- GRB 050421: Optical observations at the INT
- Swift Detection of GRB050421
- Swift-BAT detection of the bright and long GRB 050418
- GRB 050416B: optical observations
- Swift-BAT detection of GRB 050416b
- GRB 050416: Swift/UVOT detection of afterglow emission
- GRB 050416: KAIT observations
- Swift BAT/XRT Detection of GRB 050416
- GRB 050412: Subaru observations
- GRB 050412: optical observations
- GRB 050408: refined XRT analysis, no jet break seen yet
- Swift-BAT Detection of GRB 050412: A Bright, Long Burst
- GRB 050412: IR Observations
- GRB 050408: PROMPT VRcIc Observations
- GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
- GRB050410 : Null detection report
- Swift-BAT detection of GRB 050410
- GRB 050408: Mercator Optical Observations
- GRB 050408 optical candidate
- GRB050401: Radio Detection
- Swift-UVOT Optical Counterpart Candidate to XRF 050406
- GRB 050406: Magellan optical observations
- Swift-BAT detection of GRB 050406
- Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
- GRB 050402A: IR Analysis
- GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
- Swift-BAT detection of GRB 050401
- Swift-BAT detection of GRB 050331b
- Swift-BAT detection of GRB 050331
- Swift-BAT detection of a bright GRB 050326
- Swift-BAT detection of a bright outburst from SGR1806-20
- Swift-BAT trigger 112060 is not a real GRB
- GRB 050319: ROTSE-III Refined Analysis
- GRB 050319: Swift-UVOT detection of the afterglow
- GRB 050319: NIR afterglow candidate
- GRB 050319:Near IR afterglow
- Swift Detection of GRB 050319
- GRB 050319: Detection of Possible Optical Counterpart
- GRB 050318: Swift/UVOT detection of afterglow emission
- Swift-BAT detection of GRB 050318
- GRB 050315, SMARTS optical afterglow decay
- GRB 050306: ROTSE-III early limits
- GRB 050315, SMARTS optical/IR afterglow observations
- Non-detection of GRB050315 in ATCA Radio Observations
- Swift-BAT detection of GRB 050315
- GRB050223: No XMM-Newton OM detection of afterglow emission
- GRB 050306: Radio Observations
- GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
- Swift-BAT trigger 107873: No Swift XRT counterpart
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- GRB 050306: Swift-BAT detection of a long burst
- GRB 050223: optical observations
- INTEGRAL detection of GRB 050223
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB 050223 Swift/BAT detection of a burst
- GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: Optical and near-IR observations from LCO
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: Swift-BAT detection of a burst
- GRB 050219a, optical observations
- GRB050219a: No Swift UVOT Detection of Afterglow Emission
- GRB 050219: Swift-BAT detection of a burst
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB 050215B: candidate afterglow
- GRB050215b: No Swift UVOT Detection of Afterglow Emission
- GRB050215a: No Swift UVOT Detection of Afterglow Emission
- short/hard GRB 050202, optical observations
- SGR1806-20: Swift-BAT detection of a large normal burst
- GRB050128: Faulkes Telescope South observations
- GRB 050128: near-infrared observations with REM
- SGR 1806-20: GMRT results at 240 MHz band.
- SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
- GRB050126: MASTER optical limit for KECK OT
- GRB 050126: Detection of NIR afterglow with Keck/NIRC
- GRB 050126: Prompt XRT detection and localization
- GRB050124: No Swift UVOT Detection of Afterglow Emission
- GRB 050124, SMARTS optical/IR observations
- GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
- CFHTLS optical transient unlikely to be a GRB
- GRB050117b: Swift-BAT detection of a weak burst
- GRB050117: Swift-BAT detection of a long multi-peaked burst
- SGR 1806-20: Further low frequency GMRT results
- SGR1806: Optical Transient Candidates in SOHO/LASCO Images
- SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
- Second-epoch VLA observations of SGR 1806-20
- SGR1806: Detection of a Sudden Ionospheric Disturbance
- DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
- SGR1806 VLA Observations
- Detection of the SGR 1806-20 giant outburst back-scattered by the
- GRB041228: Swift-BAT detection of a burst
- GRB041219; RXTE ASM Observations
- GRB041226: Swift-BAT detection of a burst
- GRB041224: Swift-BAT detection of a soft burst
- Swift-BAT Time History of GRB041219
- GRB 041223: Detection of Optical Transient with LCO40
- GRB041223: Swift XRT Detection of X-ray Afterglow Emission