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 050904: more VLT NIR observations
- GRB 050904: BOOTES early R-band observation
- GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
- GRB 050906: Bright galaxy in BAT error box
- GRB 050906: Swift/BAT Detection of a possible burst
- GRB 050904: More SOAR
- GRB 050904: photometric redshift
- GRB 050904: Swift/UVOT observations
- GRB 050904: Afterglow Astrometry
- GRB 050904: NIR object inside the XRT error box
- GRB 050904: early Swift XRT analysis results
- GRB 050904: SOAR YJ and PROMPT Ic Observations
- GRB 050904: BAT refined analysis of partial data set
- GRB 050904: TAROT optical measurements
- GRB050904: Optical Observations
- GRB 050904: Environmental Constraints
- GRB 050904: Possible High-Redshift GRB
- GRB 050904: SOAR/PROMPT Observations
- GRB050904: P60 Observations
- GRB 050904: TAROT optical limits
- GRB050904: Swift-BAT detection of a probable burst
- Swift-BAT triggers 153461-153465 are not GRBs
- Retraction of Swift-BAT trigger #153355
- GRB 050824: MDM Observations
- GRB 050827: Swift XRT preliminary analysis results
- IBAS Alerts 2641 and 2642: not a real GRB
- Swift Trigger #152652 is not a GRB
- GRB 050827 : OSN 1.5m optical observations
- GRB 050827: P200 NIR Observations
- GRB050827: Swift/UVOT upper limits
- GRB 050827: Optical Limit
- GRB 050827: XRT possible afterglow detection
- GRB 050826 : Lulin R band observation
- GRB050824: Maidanak optical limits
- GRB050820A: RTT150 optical observations
- GRB050827: RTT150 optical observations
- GRB 050827: Swift-BAT refined analysis
- GRB050827: Swift-BAT detection of a burst
- Subaru Observations of GRB050724
- GRB 050826: Optical Candidate
- GRB050824, HETE-2 Observation
- GRB 050826: Swift XRT preliminary analysis results
- GRB 050826: BAT refined analysis
- GRB050826: Swift/UVOT early upper limits
- GRB050824: First 2 hours of power low optical decay?
- GRB 050826: Swift XRT position
- GRB050826: Swift-BAT detection of a long burst
- GRB050824: MASTER final analysis of the OT observations
- Possible GRB050825:MASTER optical observations
- Swift-BAT trigger 152038 is definitely not a GRB
- GRB050824: CORRECTION to UVOT observing times
- Swift-BAT trigger 152038 is probably not a GRB
- GRB050824: Swift/UVOT detection of fading afterglow
- GRB050824: decay of the XRT light curve and updated X-ray spectrum
- GRB050824, I-band imaging
- GRB050824: Radio Observations
- GRB 050824: Spectroscopic redshift from the VLT
- GRB 050822: refined XRT analysis
- GRB 050824: XRT refined analysis and possible afterglow detection
- 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
- GRB050824: Swift-BAT detection of a burst
- GRB 050824 optical candidate
- GRB050820A: RTT150 optical observations
- GRB050820a: PROMPT RcIc Observations
- GRB050815: Maidanak optical observation
- XRF050509c: Radio upper limits from GMRT
- VLT/UVES spectroscopy of GRB050820
- GRB050822: Swift/UVOT upper limits
- 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
- GRB050820B XMM-Newton observation
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820B: Planned XMM-Newton observation
- SUBJECT: GRB050820B: Refined analysis of the Swift-BAT burst
- GRB050820B: BAT-Swift detection of a bright GRB
- Swift/UVOT photometry of GRB050820
- 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: refined XRT analysis
- GRB050819: RTT150 optical observations