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').
- GRB040924: MASTER: OT decay
- GRB040924: MASTER Optical observations
- IPN triangulation of GRB040924 (H3564)
- GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
- GRB040924 (H3564): Optical afterglow candidate
- XRF 040912: Radio Observations
- XRF 040916: Radio Observations
- GRB040912(=H3557): Chandra Candidate X-ray Afterglow
- XRF040916: continuing decay of OT
- TAROT Observations of GRB 040916 (HETE #3558)
- GRB040912(=H3557): Candidate Optical Afterglow
- XRF040916, optical observations
- XRF040916: Optical Transient Candidate by Subaru
- GRB040916 optical limits 17 min after GRB
- XRF 040912, identification of CXO sources
- XRF 040912 (=H3557): Spectral and Temporal Properties
- XRF040916, Ic observations
- XRF040916: optical follow-up observations
- XRF040912, BVRcIc field calibration
- XRF040916, BVRcIc field calibration
- GRB040916: Archival optical observations
- XRF 040916, optical follow-up
- GRB040912(=H3557): Observations with the Chandra X-ray Observatory
- GRB040916: Optical observations
- ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
- GRB040916 (= H3558): Improved Localization from HETE WXM
- GRB040916 (= H3558): A Long XRF Localized by HETE
- 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
- GRB040912 : Kiso Optical follow-up observation
- IBAS GRB Alerts 1978-1980
- Optical observations of field of GRB040912
- HETE 3557: Optical observations
- 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
- GRB040903, REM near-IR 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
- GRB040825A: Optical observations
- GRB040825A: Optical observations
- 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
- GRB040827 XMM-Newton observation
- GRB040825A: optical limit before GRB
- MASTER: GRB040827 possible OT
- 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
- GRB040825A: optical observations
- GRB040825B: optical observations
- GRB040825B (=H3510): An XRF Localized in Real Time by HETE
- GRB 040825A: Optical observations.
- MASTER: GRB040825a optical observation
- MASTER: GRB040825b optical observation
- GRB040825B: Correction to GCN 2657
- GRB 040825: Optical observations
- XRF040812: possible afterglow second Chandra observation
- GRB 040812: Second epoch CXO Observations
- GRB040823,optical observation
- XRF040812: GMRT observations
- 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
- Bursting activity from SGR 1806-20 detected with IBAS
- 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
- XRF040701: Optical Observations at ESO