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').
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"
32796 results found.
- GRB040912(=H3557): Chandra Candidate X-ray Afterglow
- XRF040916: continuing decay of OT
- TAROT Observations of GRB 040916 (HETE #3558)
- XRF040916, optical observations
- XRF040916: Optical Transient Candidate by Subaru
- GRB040916 optical limits 17 min after GRB
- XRF 040912 (=H3557): Spectral and Temporal Properties
- XRF040916, Ic observations
- XRF040912, BVRcIc field calibration
- XRF040916, BVRcIc field calibration
- GRB040916: Archival optical observations
- GRB040912(=H3557): Observations with the Chandra X-ray Observatory
- GRB040916: Optical observations
- ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
- GRB040912 (= H3557): Chandra Observations Scheduled
- GRB 040912: Optical Observations
- GRB/XRF040912,optical observations
- GRB 040912, BVRI observations
- Optical observations of GRB/XRF 040912 = HETE 3557
- An intense burst from SGR1806-20
- IBAS GRB Alerts 1978-1980
- Optical observations of field of GRB040912
- GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
- GRB 040827: XMM-Newton data
- GRB040903 - A XRF?
- GRB040827: analysis of the XMM-Newton observation
- GRB 040903 - INTEGRAL data analysis
- IBAS Alert 1974. Not a real GRB
- Very bright burst detected from SGR 1806-20
- ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
- Possible GRB 040903 - further analysis
- Possible GRB 040903 detected with INTEGRAL
- GRB 040827 - Radio Observations
- XMM-Newton Images of GRB 040827
- GRB 040827: optical and NIR observations at the VLT
- GRB 040827: UKIRT - 2nd epoch K-band imaging
- GRB 040827: 2nd epoch of Magellan K-band imaging
- GRB 040827: K imaging - no evidence of variability
- GRB 040827: Detection of NIR afterglow
- GRB 040827: Possible detection of optical afterglow
- GRB 040827: RTT150 optical observations
- GRB040825A: optical limit before GRB
- GRB 040825B: Optical observations
- GRB040827 optical observations
- GRB 040827 : Planned XMM-Newton observation
- GRB 040827 - Refined position
- GRB 040827 : peak flux
- GRB 040827 - A long GRB detected by INTEGRAL
- GRB040825B, BVRcIc field photometry
- GRB040825A, BVRcIc field photometry
- GCN GRB OBSERBATION REPORT
- GRB 040825A,optical observations
- Increase of SGR 1806-20 activity
- GRB 040825A: Optical observations.
- GRB040825B: Correction to GCN 2657
- GRB 040825: Optical observations
- GRB 040812: Second epoch CXO Observations
- GRB040823,optical observation
- Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
- XRF 040812: optical observation at VLT
- GRB 040812: Optical counterparts of CXO sources
- XRF040812: possible afterglow
- CXO observation of GRB 040812
- IPN/HETE localizations of GRB040810 (=H3489)
- GRB 040812: Keck and LCO optical observations
- GRB 040812: Keck and LCO observations
- GRB 040812: radio observations
- GRB040812, optical/IR observations
- Konus-Wind observation of GRB040810 (=H3489)
- GRB 040812: a long GRB detected by INTEGRAL
- GRB 040810: Optical observations of a limited region
- IPN/HETE triangulation of GRB040802 (=H3485)
- GRB 040730, infrared observations
- GRB 040730: Optical observations
- GRB 040730: a long GRB detected with INTEGRAL
- Ongoing activity of SGR 1806-20
- GRB040624: optical monitoring at TNG
- Cancellation of IBAS/INTEGRAL GRB alerts
- IBAS Alert 1836: NOT a real GRB
- GRB040709 J,H-band observations
- GRB 040624: optical observations
- GRB 040624: optical observations at TNG and VLT
- MASTER: GRB 040624 optical observation after 0,48d
- GRB 040624: R-band observations
- GRB 040624, optical observations
- GRB 040624 - A long GRB detected with INTEGRAL
- GRB 030329: Rebrightening of hyperluminal ejecta.
- IPN Summary of SGR1806-20 Activity in 2004
- GRB040511: Retraction of redshift identification
- MASTER:HETE Alert 3259 (SRG1806-20) optical observation
- GRB 040606: Optical observations
- MASTER: HETE Alert 3274 optical observation
- Activivty of SGR 1806-20
- IPN triangulation of an intense intermediate burst from SGR1806-20
- GRB 040511, very fast decay?
- GRB 030324: Detection and Color of Host Galaxy
- GRB 040511: NIR observations with REM
- GRB040511: Redshift identifcation
- GRB 040511: Optical limit
- IBAS GRB Alerts n.1785 to 1791