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"37512 results found.
- GRB050815: Maidanak optical observation
- XRF050509c: Radio upper limits from GMRT
- VLT/UVES spectroscopy of GRB050820
- GRB 050820A BAT observations of second, larger episode of emission
- GRB050813: Maidanak I-band observations
- GRB 050822: Swift-BAT refined analysis
- GRB050525, GRB050607, GRB050802 BVRcIc field photometry
- GRB050820B at FRAM
- GRB050820A: RTT150 optical observations
- GRB 050820a - corrections to GCN 3846
- Swift/UVOT UV Photometry of GRB 050820B
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB 050822: Swift detection of a long burst
- Correction to Eiso calculation in GCN 3835 on GRB 050820A
- GRB050820A: Radio Observation
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB050820a BVRcIc field photometry
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820B: Refined analysis of the Swift-BAT burst
- GRB050820B: BAT-Swift detection of a bright GRB
- GRB050820: refined XRT analysis
- GRB 050820: Early RAPTOR detections
- GRB 050820 Swift-BAT refined analysis
- GRB 050820: P60 Temporal Decay Index
- GRB 050820: High Resolution Spectroscopy from Keck
- GRB050819: RTT150 optical observations
- GRB 050820: Swift detection of a GRB
- GRB 050819 Swift-BAT refined analysis
- GRB050819: Swift XRT position
- GRB050819: Swift-BAT detection of a weak burst
- Swift-BAT trigger 150993 is not a GRB
- Swift Trigger 150823 is HETE J1900.1-2455
- GRB 050817: Optical observations
- GRB 050815: Radio Observation
- GRB050814: Radio Observation
- GRB050817: Negative Optical Observations
- GRB 050814: continued fading
- GRB 050813: Radio Observations
- GRB050815: Refined analysis of the Swift-BAT burst
- GRB 050815: ROTSE-III Optical Limits
- GRB050815: Swift XRT afterglow localization
- GRB 050730: Third Epoch WSRT Radio Observations
- GRB050814: Fading red source
- GRB 050813: Gemini Spectra Revisited
- GRB 050813: Non-fading of afterglow candidate
- GRB 050814: XRT refined analysis
- 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
- GRB 050813: Swift XRT afterglow localization
- RBO GRB 050714A and GRB 050716 observations
- GRB 050813: Possible Short Swift-BAT GRB
- 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
- 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
- GRB 050803: RTT150 optical observations
- GRB050803: CrAO optical observations, possible OT candidate
- 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
- 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
- GRB 050730: OHP optical observations