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').
- GRB050223 XMM-Newton observation
- INTEGRAL detection of GRB 050223
- GRB 050223 : Planned XMM-Newton observation
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB050223: ROTSE-III Optical Observations
- GRB 050223 Swift/BAT detection of a burst
- GRB 050223: Swift XRT Position
- HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: CORRECTION to refined XRT position
- GRB 050219a: Optical observations from LCO
- GRB 050219b: Optical and near-IR observations from LCO
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: Refined XRT position
- GRB 050219b: Swift-BAT detection of a burst
- GRB 050219b: CORRECTION: Swift XRT Position
- GRB 050219b: Swift XRT Position
- GRB 050219a, optical observations
- GRB 050219a: Refined XRT position
- GRB050219a: No Swift UVOT Detection of Afterglow Emission
- GRB 050219: Swift-BAT detection of a burst
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB 050219: Prompt X-ray position
- GRB 050215B: Radio Observations
- GRB 050215b: XRT confirmation of IR afterglow candidate
- GRB050215b: P60 Optical Observations
- GRB 050215b: Swift XRT Source Variability
- GRB 050215B: candidate afterglow
- GRB 050215b : Lulin follow-up observation
- GRB 050215b, BOOTES-2 simultaneous optical observations
- GRB 050215B: UKIRT K-band imaging
- GRB 050215b: Swift XRT Observations
- GRB050215b: No Swift UVOT Detection of Afterglow Emission
- GRB050215a: No Swift UVOT Detection of Afterglow Emission
- Swift-BAT detects two bursts: GRB050215a and GRB050215b
- GRB 050215b, BOOTES-1B optical limit
- GRB050215B: ROTSE-III optical observations
- GRB050215A: ROTSE-III Optical Observations
- GRB050209: TAROT optical observations
- GRB 050209(=U11568): Duration and spectrum
- short/hard GRB 050202, optical observations
- GRB050209: REM optical observations
- GRB 050209 I-band observation
- GRB 050209 Optical observations
- GRB050209: P60 Optical Observations
- GRB050209 (=U11568): A Long GRB Detected by HETE
- GRB 050209: Optical observation
- GRB 050128: Radio observations
- Further analysis of the short Swift-BAT GRB 050202
- GRB 050202: Second epoch radio observations
- GRB 050129: Optical observations
- GRB050202: Radio Observations
- GRB 050202: Optical observations with LCO40
- GRB 050202: Short burst detected by Swift-BAT
- GRB 050128 Optical observation with REM
- GRB 050129: a weak long GRB detected with INTEGRAL
- SGR1806-20: Swift-BAT detection of a large normal burst
- GRB050128: Faulkes Telescope South observations
- GRB 050124: Radio Observations
- GRB 050128: near-infrared observations with REM
- GRB050128,optical observations
- GRB 050126: A NIR afterglow candidate in the revised XRT error circle
- GRB050126: Updated Swift XRT Position
- SGR 1806-20: GMRT results at 240 MHz band.
- SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
- GRB 050126: Radio Observations
- GRB050128 Swift-BAT observations
- GRB 050128: Swift XRT prompt afterglow position
- HETE #3667: P60 Observations
- GRB 050124: K-band afterglow observations
- GRB050126: MASTER optical limit for KECK OT
- GRB050126: Burst Parameters Measured by BAT
- GRB050126: MASTER optical observations
- GRB 050126: Detection of NIR afterglow with Keck/NIRC
- GRB 050126: Prompt XRT detection and localization
- GRB 050124: NIR afterglow confirmed with Keck/NIRC
- GRB050124: No Swift UVOT Detection of Afterglow Emission
- GRB 050124, SMARTS optical/IR observations
- GRB 050117a: Radio Observations
- GRB 050124 I-band observation
- GRB 050124: NIR Candidates from Keck/NIRC
- GRB050124,optical observation
- GRB 050124 : Lulin R-band follow-up observation
- GRB050124: Updated Swift XRT Position and Fluxes
- GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
- GRB050124: Refined BAT position, spectral and fluence information
- GRB050124: Swift-BAT position of a double-peaked burst
- GRB 050123 : I-band follow-up observation
- GRB050123: optical limit 1.8h before GRB
- GRB050123,optical observation
- GRB 050123: KAIT observations
- GRB050123: P60 Observations
- GRB 050123(=H3666): A GRB Localized in Real Time by HETE
- CFHTLS optical transient unlikely to be a GRB
- Unusual optical transient (GRB ???)
- GRB050117a: Radio Observations
- GRB050117a: Refined analysis
- GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations