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').
- 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
- GRB050117: Palomar WIRC Ks-band observations
- GRB050117b: Swift-BAT detection of a weak burst
- GRB050117: optical observation
- GRB 050117, I-band observations
- GRB 050117: Optical observation
- GRB050117: Refined XRT position
- GRB050117: MASTER optical observations
- MASTER:GRB050117 SWIFT
- GRB050117: Swift-BAT detection of a long multi-peaked burst
- GRB050117: Swift XRT Position
- SGR 1806-20: RXTE/PCA pulse frequency during flare
- Triangulation of Short Hard GRB050112 (large error box)
- SGR 1806-20: Further VLA Observations
- SGR 1806-20: Further low frequency GMRT results
- SGR 1806-20: Further VLA Observations
- SGR1806-20: Swift-BAT observations of two additional bursts
- SGR1806: Optical Transient Candidates in SOHO/LASCO Images
- Further VLA observations of SGR 1806-20
- SGR 1806-20 and extragalactic short-duration GRBs
- Further ATCA observations of SGR 1806-20
- Fourth Epoch VLA observations of SGR 1806-20
- SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
- SGR 1806-20: Temporal and Spectral behavior of radio transient
- ATCA observations of SGR 1806-20
- SGR 1806-20, RHESSI observations of the 041227 giant flare
- Third epoch observations of SGR 1806-20 with VLA
- Second Epoch VLA observations of SGR 1806-20
- Second-epoch VLA observations of SGR 1806-20
- SGR1806: Detection of a Sudden Ionospheric Disturbance
- DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
- VLA observations of SGR 1806-20
- SGR1806 VLA Observations
- VLA observations of SGR 1806-20
- SGR1806-20: RXTE-PCA observation of the 041227 super-flare
- GRB 041217: Optical observations
- SGR1806-20: Swift-BAT observation of the 041227 super-flare
- GRB041219, early time observations
- Detection of the SGR 1806-20 giant outburst back-scattered by the
- The giant outburst from SGR 1806-20
- IPN localization of giant flare from SGR1806-20
- Giant flare from SGR 1806-20 detected by INTEGRAL
- GRB041228: ROTSE-III Optical Observations
- GRB041228: Swift-BAT detection of a burst
- GRB041219; RXTE ASM Observations
- NIR Observations of GRB 041219
- GRB041226: ROTSE-III Optical Observations
- GRB041226: Swift-BAT detection of a burst
- GRB041223: decay of the afterglow
- GRB041224: ROTSE-III Optical Observations
- GRB 041224: near-infrared observations with REM