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"41197 results found.
- GRB 040511: Optical Observations
- GRB040511: Optical Observations
- GRB040511: Optical Observations
- GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
- Type Ic SN2001em (off-axis GRB jet?), optical spectrum
- GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
- IPN triangulation of GRB040425 (=H3183)
- On Line Availability of Archival HETE Fregate Data and Lightcurves
- GRB040422: optical observations at Xinglong Observatory
- GRB040422: optical observations at CrAO
- GRB 040423 (=H3175): A Long GRB Localized by HETE
- GRB040422, optical observations at Loiano
- GRB040422 : I-band follow-up observation at Lulin Observatory
- GRB 040422: ROTSE-IIIb Prompt Optical Limits
- GRB040422, BVRcIc field calibration
- GRB 040422,optical observation
- GRB040422: optical and NIR observations at the VLT
- GRB 040422: a long GRB detected with INTEGRAL
- GRB 040403, deep optical observations
- MASTER: HETE Alert 3163, 3167 technical optical observation
- INTEGRAL-SPI/ACS GRB data: timing correction
- HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
- GRB 040403: Optical Observations
- GRB 040403 Optical Observations
- GRB 040403: Optical observations
- GRB 040403: optical observations
- GRB 040403: Optical Observations
- GRB 040403: a long GRB detected with INTEGRAL
- Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
- GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
- IBAS GRB Alert 1694
- GRB040323: NIR Observations and Variable Object
- GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
- GRB 040323, a dark GRB ?
- GRB 040323: a long GRB detected with INTEGRAL
- IBAS GRB alerts 1679, 1680, 1681
- GRB040223: Deep NIR NTT data re-analysis
- GRB 040223: XMM-Newton results
- GRB040223, improved XMM position
- GRB 031203: spectoscopic evidence for a 1998bw-like SN
- GRB 031203, possible supernova
- MASTER: RXTE GRB040308 optical observation
- IBAS results on a burst from SGR1806-20
- INTEGRAL detection of activity from SGR1806-20
- RXTE GRB040229 optical observation: no candidate
- GRB 040228 Optical observations
- IPN triangulation of GRB040228 (H3066, H3067)
- GRB040228 : KISO optical follow-up observation
- GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
- GRB 040223: Deep NIR NTT observations
- GRB 040223 : Optical observation (non-detection)
- XMM-Newton Images of GRB 040223
- GRB 040223, VLA observations
- GRB 040223: REM IJK Observations
- GRB 040223 XMM-Newton observation ...
- GRB 031203 XMM-Newton observation
- GRB 040223 : Planned XMM-Newton observation
- GRB 040106 : Planned XMM-Newton observation
- GRB 040223: a long GRB detected with INTEGRAL
- GRB031111, optical observations
- GRB031220: 2nd Chandra observation and X-ray afterglow candidate
- GRB031203: Chandra Observations
- GRB040106, follow-up radio observations
- GRB040106: refined X-ray transient position
- IBAS GRB alert 1379
- SN 2003dh/GRB030329 late-time optical spectroscopy
- GRB040106, Radio Observations
- GRB040106, likely optical afterglow
- GRB040106: Second Epoch Optical Observations
- GRB 031220: Optical observations of Chandra X-ray sources
- GRB040106: optical observations with REM+ROSS
- GRB031220: observation at Univercity of Miyazaki
- GRB 040106: Optical observations
- GRB 040106 : Planned XMM-Newton observation
- GRB 040106 : a long GRB detected with INTEGRAL
- IPN triangulation of an intermediate burst from SGR1806-20
- GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
- GRB031220(=H2976): Observation with the Chandra X-ray Observatory
- IPN triangulation of GRB031219 (large error box)
- GRB031220: Palomar Observations
- GRB 031220 : Kyoto Optical Observation
- GRB 031220: Subaru observation
- GRB 031220: Optical observation at Tokyo Tech
- GRB031220: ROTSE-IIIb Optical Limits
- GRB031220 : Optical Observation of Lulin Observatory
- GRB 031203 I-band monitoring
- IPN triangulation of GRB031214 (short/hard; very intense; small error box)
- GRB 2974 follow-up observations
- GRB031203, improved XMM position
- GRB 031203: Discovery of a dust echo
- GRB 031203: SMARTS optical monitoring
- GRB 021203: A Normal GRB viewed far off axis?
- GRB 031203: Variable Radio Source
- GRB 031203: Magellan spectrum of possible GRB host
- GRB 031203: Optical/IR Astrometry
- IPN/HETE localization of GRB031203B (=H2949; large error box)
- GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
- XMM-Newton Observation of GRB031203
- GRB 031203: Deep NIR NTT & VLT observations
- GRB031203: K' Photometry of the likely GRB host