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').
- GRB 050502b : optical observation at Lulin observatory
- GRB 050502b: Swift XRT Position
- GRB 050502A: Redshift measurement based on Keck HIRES Observations
- GRB050502B: Optical Limits from ANU 1m
- Swift Detection of the Bright Burst GRB050502b
- GRB 050502: INTEGRAL results
- GRB050502: ANU 1m optical Observations
- GRB 050502: Confirmed variability of the afterglow candidate +
- GRB 050502: PAIRITEL IR Observations
- GRB050502 - Correction on the Optical Candidate from the Liverpool
- GRB050502 - Optical Candidate from the Liverpool Telescope
- GRB 050502 - A long GRB detected with INTEGRAL
- 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 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: NIR observations
- GRB 050416: Optical/NIR observations
- GRB 050421: SLOTIS observations
- GRB 050421: Further Analysis of IR imaging
- GRB050421: Radio Observations
- GRB050421: Radio Observations
- GRB 050421: Swift-UVOT observation
- GRB 050421: IR Observations
- GRB 050421: Swift-BAT refined analysis
- GRB 050421: ROTSE-III Optical Limits
- GRB 050421: NIR observations re-examination
- GRB050421
- GRB 050421: early Swift XRT analysis results
- GRB 050421: NIR observations
- GRB050421: P60 Observations
- GRB 050421: BOOTES-2 simultaneous optical observations
- GRB 050421: Optical observations at the INT
- Swift Detection of GRB050421
- GRB 050416b: Tentative Swift XRT Position
- GRB 050315: potential host galaxy
- GRB050326: analysis of the XMM-Newton observation
- GRB050418: Null Optical Observations
- GRB 050412: Chandra observations
- GRB050416A, optical observations
- GRB 050418: Swift-BAT refined analysis
- Swift-BAT detection of the bright and long GRB 050418
- GRB 050416: Mitsume optical observation
- GRB 050416 : optical observation at Xinglong observatory
- GRB 050416B: optical observations
- GRB 050416b: Swift-BAT refined analysis
- GRB 050416b: LCO observations
- GRB 050416b: LCO observations
- GRB050416B: IR observations
- GRB 050416: Swift/UVOT refined analysis
- Swift-BAT detection of GRB 050416b
- IBAS GRB Alert # 2463: not a GRB
- 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: ART observations
- GRB 050416,optical observation
- GRB 050416: KAIT observations
- GRB050416: P200 NIR 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 050408: RTT150 optical observations
- GRB050408: optical observation
- GRB 050412: PROMPT VRcIc Observations
- GRB 050408: Kuiper 1.5m 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 : XingLong optical observation
- 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 050408: SDSS Field Calibration
- GRB 050412: Optical limit
- GRB 050412: LCO Optical Observations
- GRB 050412: Optical observations
- GRB050412: P60 Observations
- GRB 050412: Swift XRT Position
- GRB050412: optical limit before and during GRB
- GRB 050412: LCO optical observations
- GRB050412: ROTSE-III Optical Limits
- Swift-BAT Detection of GRB 050412: A Bright, Long Burst
- GRB 050412: IR and Optical observations
- GRB 050412: IR Observations
- GRB050408: Radio Observations
- GRB 050401: Optical limit