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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"4253 results found.
- GRB050607: P60 Observations
- Konus-Wind observation of GRB 050603
- GRB 050603: Swift XRT Position
- GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
- GRB 050603: INTEGRAL shows it is not a short GRB
- Swift/BAT Detection of GRB050603
- GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
- GRB 050525a: SARA Observations
- XRF 050522: Swift XRT observation
- RBO Observations of GRB050520
- GRB 050509b: No Optical Variability in XRT Error Circle
- GRB050416: Afterglow detection at 188 nm with Swift UVOT
- GRB050509c (=H3751): An X-Ray Flash Localized By HETE
- Swift Detection of GRB050509b: A short duration burst
- GRB 050502a: Optical Observations
- Renewal of SGR 1806-20 activity
- GRB 050502A: WSRT Radio Observations
- GRB050502A: Optical Observations
- GRB 050502: Confirmed variability of the afterglow candidate +
- GRB050502 - Correction on the Optical Candidate from the Liverpool
- 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 050421: IR Observations
- Swift Detection of GRB050421
- GRB050408: optical observation
- GRB050408: Radio Observations
- GRB 050408,optical observation
- GRB 050408, optical observations
- GRB 050319 : Confirmation of optical afterglow decay
- GRB050318: Swift XRT position
- GRB050309: CONCAM pre-trigger and trigger coincident optical
- GRB 050306: further TAROT optical data
- Ongoing activity of SGR 1806-20 after the giant flare
- GRB050215A: ROTSE-III Optical Observations
- GRB 050129: a weak long GRB detected with INTEGRAL
- SGR 1806-20: GMRT results at 240 MHz band.
- SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
- GRB050117: Refined XRT position
- SGR 1806-20: RXTE/PCA pulse frequency during flare
- SGR 1806-20: Further VLA Observations
- SGR 1806-20: Further low frequency GMRT results
- SGR 1806-20: Further VLA Observations
- 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
- Detection of the SGR 1806-20 giant outburst back-scattered by the
- The giant outburst from SGR 1806-20
- Giant flare from SGR 1806-20 detected by INTEGRAL
- Very high activity of SGR 1806-20
- Summary of the recent bursts from SGR 1806-20
- IBAS GRB Alert # 2034
- Bright bursts from SGR1806-20
- GRB041006, submillimetre observations
- Konus-Wind observation of a series SGR 1806-20 bursts on 041005
- Bursts from SGR 1806-20: Preliminary INTEGRAL results
- Very strong outburst from SGR 1806-20 detected with INTEGRAL
- SGR 1806-20 still active
- GRB 040924: Second Epoch WSRT Radio Observations
- GRB040929,optical observation
- GRB040916: Optical observations
- ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
- An intense burst from SGR1806-20
- Very bright burst detected from SGR 1806-20
- GRB 040827 : Planned XMM-Newton observation
- GRB 040827 - A long GRB detected by INTEGRAL
- Increase of SGR 1806-20 activity
- Bursting activity from SGR 1806-20 detected with IBAS
- Ongoing activity of SGR 1806-20
- XRF040701: Second-Epoch Chandra Observations
- XRF040701: First-Epoch Chandra Observations
- GRB040709 J,H-band observations
- GRB040706:observation at University of Miyazaki
- IPN Summary of SGR1806-20 Activity in 2004
- SGR 1806-20: no IR variability of the proposed counterparts
- SGR 1806-20, potential NIR counterpart
- MASTER: HETE Alert 3274 optical observation
- Activivty of SGR 1806-20
- IBAS GRB Alerts n.1785 to 1791
- GRB 040422: a long GRB detected with INTEGRAL
- Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
- IBAS GRB Alert 1694
- short hard GRB 040322
- IBAS GRB alerts 1679, 1680, 1681
- IBAS results on a burst from SGR1806-20