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"
18399 results found.
- GRB 050509B: Swift/XRT refined analysis
- GRB050509a: Swift UVOT observations
- GRB 050509b: Optical observations
- GRB 050509b: Possible Optical Counterpart
- GRB 050509A: Optical observations
- GRB 050509b: Swift-BAT refined analysis of the short hard burst
- GRB 050509b: optical observations
- GRB 050509b: Swift XRT Position
- GRB 050509B: ROTSE-III Optical Limits
- Swift Detection of GRB050509b: A short duration burst
- GRB 050509a: Swift XRT Position
- Swift Detection of the Burst GRB050509
- Swift-BAT detection of GRB 050507
- GRB 050505: early time observations
- GRB 050505 - Faulkes Telescope North observations
- GRB 050502a: Swift XRT Upper Limit
- GRB 050505, simultaneous optical observation
- GRB 050505: Further Swift UVOT observations.
- GRB050416A : 1 GHz limit from GMRT
- GRB 050505 UVOT
- GRB 050505: Swift XRT Position
- GRB050505 Swift-BAT refined analysis
- GRB 050416b:Swift XRT afterglow upper limits
- GRB 050416b:Swift XRT afterglow upper limits
- Swift-BAT detection of GRB050505
- GRB 050504: Swift XRT position
- Swift UVOT observation of GRB 050504
- GRB 050502b, V band Observations
- GRB050502B Swift-BAT refined analysis
- GRB050502B: I band source in XRT error circle
- Swift UVOT refined analysis
- Retraction of Swift-BAT trigger 116145
- GRB 050502b : optical observation at Lulin observatory
- GRB 050502b: Swift XRT Position
- GRB050502B: Optical Limits from ANU 1m
- Swift Detection of the Bright Burst GRB050502b
- GRB050502: ANU 1m optical Observations
- Swift-BAT Trigger 115881 is not a real GRB
- Swift/BAT possible detection of a weak burst GRB050430
- GRB 050401: Rc observation
- GRB050416a: Radio Detection
- GRB 050422: Swift-UVOT observation
- GRB 050422: Swift-BAT refined analysis
- GRB 050422: Swift XRT Position
- Swift Detection of GRB 050422
- GRB 050421: SLOTIS observations
- GRB050421: Radio Observations
- GRB050421: Radio Observations
- GRB 050421: Swift-UVOT observation
- GRB 050421: Swift-BAT refined analysis
- GRB 050421: ROTSE-III Optical Limits
- GRB 050421: early Swift XRT analysis results
- GRB 050421: BOOTES-2 simultaneous optical observations
- GRB 050421: Optical observations at the INT
- Swift Detection of GRB050421
- GRB 050416b: Tentative Swift XRT Position
- GRB050326: analysis of the XMM-Newton observation
- GRB 050418: Swift-BAT refined analysis
- Swift-BAT detection of the bright and long GRB 050418
- GRB 050416B: optical observations
- GRB 050416b: Swift-BAT refined analysis
- GRB 050416: Swift/UVOT refined analysis
- Swift-BAT detection of GRB 050416b
- GRB050412: Radio Observations
- GRB 050416: Swift/UVOT detection of afterglow emission
- GRB050416: Refined Swift-XRT analysis
- GRB050416: Maidanak optical observations
- GRB 050416: Swift-BAT refined analysis
- GRB 050416,optical observation
- GRB 050416: KAIT observations
- GRB 050416: Swift XRT Position
- GRB 050416: Radio observations
- Confirmation of OT for GRB050416
- GRB050416: P60 Afterglow Candidate
- Swift BAT/XRT Detection of GRB 050416
- GRB 050412: Subaru observations
- GRB 050412: optical limit
- GRB 050412: optical observations
- GRB 050408: refined XRT analysis, no jet break seen yet
- GRB 050412: early Swift XRT analysis results
- GRB 050412: Swift-BAT refined analysis
- GRB 050412: ANU 2.3m observations
- GRB 050412: Early Optical/Ultraviolet Observations with
- GRB 050412: retraction of UVOT transient report
- GRB 050412: UVOT transient not in XRT error circle
- GRB 050412: Swift XRT Position
- GRB050412: optical limit before and during GRB
- GRB050412: ROTSE-III Optical Limits
- Swift-BAT Detection of GRB 050412: A Bright, Long Burst
- GRB 050412: IR Observations
- GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
- GRB 050410, optical observations
- GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
- GRB 050410 R band Optical Observations
- GRB050410 : Null detection report
- GRB 050410, optical observations
- GRB050410: Radio Observations
- GRB 050408: Swift XRT measurement of possible jet break
- GRB050410: MASTER optical observations
- GRB 050410: Early observations with Swift-UVOT