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"45463 results found.
- GRB050815: Refined analysis of the Swift-BAT burst
- GRB 050815: ROTSE-III Optical Limits
- GRB050815: Swift XRT afterglow localization
- GRB050815: Swift-BAT detection of a burst
- GRB 050730: Third Epoch WSRT Radio Observations
- GRB050814: Fading red source
- GRB 050813: Gemini Spectra Revisited
- GRB050814: P60 Optical Afterglow Candidate
- GRB 050813: Non-fading of afterglow candidate
- GRB 050814: XRT refined analysis
- GRB050814: SWIFT/UVOT observation
- GRB050814: Refined analysis of the Swift-BAT burst
- GRB050813: Gemini Imaging
- GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050814: Swift detection of a burst
- GRB 050813: Magellan detection of a high redshift galaxy cluster
- GRB050813: RTT150 optical observations
- GRB 050813: I-band observations
- GRB050813, SDSS pre-burst observations
- GRB 050813: KAIT optical limit
- GRB 050813: Swift-BAT refined analysis
- GRB 050813: Photometry of object in XRT error circle
- GRB050813: SWIFT/UVOT observation
- GRB 050813: Swift XRT afterglow localization
- RBO GRB 050714A and GRB 050716 observations
- GRB 050813: Possible Short Swift-BAT GRB
- GRB050813 (Swift 150139): P60 Observations
- Swift-BAT trigger 150131 is not a GRB
- GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
- Ongoing activity of SGR 1806-20: an intermediate burst 050811
- GRB050803: CrAO optical observations, no OT candidate
- Detection of an intermediate burst from SGR 1806-20 on August 8
- GRB 050730: WSRT Radio Observations
- GRB 050803: PROMPT BVRcIc Observations
- GRB 050807: ROTSE-III Optical Limits
- GRB 050730, optical observation
- GRB050805b: CrAO optical limit
- GRB050805a : Null detection report
- GRB050730, optical observations
- GRB050803, optical observations
- Swift-BAT trigger 149118 is very likely not a GRB
- Retraction of Swift Trigger 149131 (GRB 050805B)
- GRB 050805b: OHP optical limits
- GRB 050805b: TAROT optical limits
- GRB050805b: MASTER optical observations
- Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
- GRB050805a: MASTER optical candidat
- Swift-BAT trigger 149118 is probably not a GRB
- GRB050802: TNG optical observations
- GRB050803: Radio Observation
- GRB 050803: RTT150 optical observations
- GRB050801: Radio Observation
- GRB050730: Radio Detection
- GRB050803: CrAO optical observations, possible OT candidate
- GRB050803: Optical/UV Upper Limits from Swift-UVOT
- GRB 050803: Keck Observations
- GRB 050803: Swift-BAT refined analysis
- GRB 050802.422: Fading of the afterglow and detection of the host
- GRB050803: MASTER further analys
- GRB 050803, optical observations
- GRB 050803: Magellan Observations
- GRB 050803: early Swift XRT analysis results
- GRB 050803: TAROT optical limits
- GRB050803: MASTER optical observations
- GRB050802: Tentative absorption redshift
- GRB050803: Swift-BAT detection of a very long burst
- GCN GRB observation 050713A
- GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
- GRB 050802: Swift/UVOT optical and UV detections
- GRB050802: CrAO optical observations
- GRB050801: Unchanged decay slope
- GRB050802 radio non-detection
- GRB 050730: OHP optical observations
- GRB 050802: early Swift XRT analysis results
- GRB 050802: Swift/UVOT observations
- GRB 050802 : Lulin Optical follow-up observation
- GRB 050802: Swift-BAT refined analysis
- GRB050801: Optical photometry and decay index
- GRB 050802: XRT position
- GRB 050802: Swift Gamma-ray Burst
- GRB050801: Swift/UVOT Optical and UV detections
- GRB 050730: Preliminary Analysis of MIKE Spectrum
- GCN 050801: early Swift XRT analysis results
- GRB 050801: Swift-BAT refined analysis
- GRB 050801, SMARTS optical/IR afterglow observations
- GRB 050801, afterglow observations
- GRB 050730, corrected photometry and break?
- GRB 050801: ROTSE-III Early Afterglow Break
- GRB050801: Swift-BAT detection of a burst
- GRB 050801: ROTSE-III Detection of Possible Counterpart
- GRB 050730: XRT refined analysis
- Correction to GCN Circ 3476 on GRB050525A
- GRB 050730: early TAROT optical observations
- GRB 050726: PROMPT Rc Observations
- GRB 050730: RTT150 optical observations
- Swift/UVOT photometry of GRB050730
- GRB 050730, spectra and optical photometry
- GRB050730: Refined BAT analysis of the Swift-BAT burst
- GRB 050730: Swift XRT afterglow observations