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"23706 results found.
- GRB050911: Swift UVOT followup observations
- GRB 050911: Swift-BAT refined analysis
- GRB050911: Swift-BAT detection of a long burst
- GRB050908: detection of Swift/UVOT optical counterpart
- RBO GRB 050908 observations
- WIRO observations in I of GRB 050908
- GRB 050906: Possible X-ray Counterpart
- GRB050908: Swift/UVOT Early upper limits
- GRB 050908: Swift-BAT refined analysis
- GRB 050908: Prompt PROMPT Observations
- GRB050904: CrAO optical observations
- GRB 050906: Swift-BAT refined analysis
- GRB050906: P60 Observations
- GRB 050904: BOOTES early R-band observation
- GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
- GRB 050904: More SOAR
- GRB 050904: Swift/UVOT observations
- GRB 050904: early Swift XRT analysis results
- GRB 050904: SOAR YJ and PROMPT Ic Observations
- GRB 050904: SOAR/PROMPT Observations
- GRB050904: P60 Observations
- GRB050904: Swift-BAT detection of a probable burst
- Swift-BAT triggers 153461-153465 are not GRBs
- IBAS Alerts 2641 and 2642: not a real GRB
- GRB 050827: P200 NIR Observations
- GRB050827: Swift/UVOT upper limits
- GRB 050827: Swift-BAT refined analysis
- Subaru Observations of GRB050724
- GRB 050826: Optical Candidate
- GRB 050826: Swift XRT preliminary analysis results
- GRB050826: Swift/UVOT early upper limits
- GRB050824: First 2 hours of power low optical decay?
- GRB050824: MASTER final analysis of the OT observations
- Possible GRB050825:MASTER optical observations
- GRB050824: CORRECTION to UVOT observing times
- Swift-BAT trigger 152038 is probably not a GRB
- GRB050824: Swift/UVOT detection of fading afterglow
- GRB050824, I-band imaging
- GRB 050824: BAT refined analysis of a soft weak burst
- GRB050824: MASTER:OT decay
- GRB050824: MASTER observation OT
- GRB050805a: MASTER optical candidat
- GRB 050824: ROTSE-III Optical Limits
- GRB050820a: PROMPT RcIc Observations
- XRF050509c: Radio upper limits from GMRT
- GRB050822: Swift/UVOT upper limits
- GRB 050820A BAT observations of second, larger episode of emission
- GRB 050822: Swift-BAT refined analysis
- GRB 050820a - corrections to GCN 3846
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB 050820B: Swift XRT position
- Swift/UVOT photometry of GRB050820
- GRB050820: Optical afterglow from P60
- Swift-BAT trigger 150993 is not a GRB
- Swift Trigger 150823 is HETE J1900.1-2455
- GRB050817: Negative Optical Observations
- GRB050815: Optical afterglow detection by Swift UVOT
- GRB 050815: ROTSE-III Optical Limits
- GRB050815: Swift XRT afterglow localization
- GRB050814: SWIFT/UVOT observation
- GRB050813: Gemini Imaging
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050813: Swift-BAT refined analysis
- GRB050813: SWIFT/UVOT observation
- GRB 050813: Swift XRT afterglow localization
- RBO GRB 050714A and GRB 050716 observations
- GRB 050813: Possible Short Swift-BAT 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 050803: PROMPT BVRcIc Observations
- GRB050805a : Null detection report
- Swift-BAT trigger 149118 is very likely not a GRB
- GRB050805b: MASTER optical observations
- GRB050805a: MASTER optical candidat
- GRB050803: CrAO optical observations, possible OT candidate
- GRB 050803: Swift-BAT refined analysis
- GRB050803: MASTER further analys
- GRB050803: MASTER optical observations
- GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
- GRB050802: CrAO optical observations
- GRB 050802: Swift-BAT refined analysis
- GRB 050802: Swift Gamma-ray Burst
- GCN 050801: early Swift XRT analysis results
- GRB 050801: Swift-BAT refined analysis
- GRB 050801, SMARTS optical/IR afterglow observations
- GRB050801: Swift-BAT detection of a burst
- GRB 050801: ROTSE-III Detection of Possible Counterpart
- GRB 050730: XRT refined analysis
- GRB 050726: PROMPT Rc Observations
- Swift/UVOT photometry of GRB050730
- GRB 050730: Swift XRT afterglow observations
- GRB 050730: PROMPT VRcIc Observations
- GRB050730, afterglow observations
- GRB 050730, SMARTS optical/IR afterglow observations
- GRB 050730, optical candidate
- GRB 050709: PROMPT Rc Observations
- GRB050713b: Maidanak optical observations