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"
3821 results found.
- GRB 060202: Gemini-N J, H, K_s observations
- GRB 051211A: MDM Observations
- GRB060130: REM infrared observations
- GRB 060116: MARGE optical observations
- GRB060121: SARA Observations
- GRB 060121: optical observations
- GRB 060114: Swift/UVOT Observations
- GRB 060111B: Refined analysis of the Swift-BAT burst
- GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
- GRB 051221: Swift/UVOT upper limits
- GRB 051211B: Swift XRT confirmation of the afterglow
- An extraordinary long burst on December 3 from SGR1806-20
- Possible resuming of the SGR 1806-20 activity
- GRB 051117A: Refined analysis of the Swift-BAT burst
- GRB050925: analysis of the XMM-Newton observation
- GRB/SGR 050925: XMM-Newton ToO observation
- GRB 051111a: IR photometry
- GRB 051008 Tautenburg Supernova Search
- GRB 051109: Rc and Ic observations
- GRB051103: MASTER: OT limit and host galaxy candidates
- IPN triangulation and Konus spectrum of the bright short/hard GRB051103
- GRB 051105b: ART optical limits
- GRB051028 SARA Observation
- SGR 1806-20: continued moderate activity seen with INTEGRAL
- GRB051021.63
- GRB 051016b: Optical limit
- GRB 051016B: Swift detection of a soft burst
- GRB050805A: Rc optical observations
- GRB/SGR 050925: IR Observations
- GRB050925: Swift-BAT detection of a short burst
- GRB 050915: Swift XRT refined analysis
- GRB 050915: ROTSE-III optical limits
- GRB050911: Upper limit on X-ray afterglow
- GRB 050906: Swift-BAT refined analysis
- GRB 050906: Bright galaxy in BAT error box
- GRB 050824: ROTSE-III Optical Limits
- GRB 050822: Swift detection of a long burst
- GRB050820: refined XRT analysis
- GRB 050820: P60 Temporal Decay Index
- GRB 050820: Swift detection of a GRB
- GRB050820: Optical afterglow from P60
- Ongoing activity of SGR 1806-20: an intermediate burst 050811
- Detection of an intermediate burst from SGR 1806-20 on August 8
- GRB050805a: MASTER optical candidat
- GCN 050801: early Swift XRT analysis results
- GRB 050730, corrected photometry and break?
- GRB050801: Swift-BAT detection of a burst
- GRB 050730: early TAROT optical observations
- GRB 050730, spectra and optical photometry
- GRB 050724: Secure Host Redshift from Keck
- GRB050713: analysis of the XMM-Newton observation
- GRB 050721A: Swift-BAT refined analysis
- GRB050721A: Swift-BAT detection of a weak burst
- GRB050716: Refined analysis of the Swift-BAT burst
- Konus-Wind observation of GRB 050713A
- GRB 050713A: RAPTOR detection of early optical emission
- Swift-BAT Trigger 145729 is not a GRB
- GRB 050713A: Swift/UVOT observation
- RBO RI observations of GRB 050713A
- GRB050713: Liverpool Telescope prompt observations
- GRB050713: possible I-band afterglow
- GRB 050713: Swift detection of Bright Burst
- GRB 050713A: ROTSE-III Optical Limits
- GRB050709: A Possible Short-Hard GRB Localized by HETE
- GRB 050626: Swift XRT observations
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- Konus-Wind observation of an intermediate burst from SGR 1806-20
- GRB 050525a, Mid-Infrared Observations
- GRB050607: P60 Observations
- Konus-Wind observation of GRB 050603
- GRB 050603: Swift XRT Position
- GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
- GRB 050603: INTEGRAL shows it is not a short GRB
- Swift/BAT Detection of GRB050603
- GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
- GRB 050525a: SARA Observations
- XRF 050522: Swift XRT observation
- RBO Observations of GRB050520
- GRB 050509b: No Optical Variability in XRT Error Circle
- GRB050416: Afterglow detection at 188 nm with Swift UVOT
- GRB050509c (=H3751): An X-Ray Flash Localized By HETE
- Swift Detection of GRB050509b: A short duration burst
- GRB 050502a: Optical Observations
- Renewal of SGR 1806-20 activity
- GRB 050502A: WSRT Radio Observations
- GRB050502A: Optical Observations
- GRB 050502: Confirmed variability of the afterglow candidate +
- GRB050502 - Correction on the Optical Candidate from the Liverpool
- GRB 050502: ROTSE-III Detection of Possible Counterpart
- Swift-BAT Trigger 115881 is not a real GRB
- Swift/BAT possible detection of a weak burst GRB050430
- GRB 050421: IR Observations
- Swift Detection of GRB050421
- GRB050408: optical observation
- GRB050408: Radio Observations
- GRB 050408,optical observation
- GRB 050408, optical observations
- GRB 050319 : Confirmation of optical afterglow decay
- GRB050318: Swift XRT position
- GRB050309: CONCAM pre-trigger and trigger coincident optical