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"22112 results found.
- XRF 040812: optical observation at VLT
- GRB 040812: Optical counterparts of CXO sources
- CXO observation of GRB 040812
- IPN/HETE localizations of GRB040810 (=H3489)
- GRB040812, optical/IR observations
- XRF040701: Optical Observations at ESO
- IPN/HETE triangulation of GRB040802 (=H3485)
- GRB 040730, infrared observations
- GRB 040730: Optical observations
- Ongoing activity of SGR 1806-20
- GRB040624: optical monitoring at TNG
- XRF 040701 - optical observations of the decaying Chandra source
- XRF040701: Second-Epoch Chandra Observations
- XRF040701: VLA Observations
- XRF040701: First-Epoch Chandra Observations
- GRB040624, optical observations
- GRB040706:observation at University of Miyazaki
- GRB 040624: optical observations
- Optical Observations of GRB040624
- GRB 040624: optical observations at TNG and VLT
- MASTER: GRB 040624 optical observation after 0,48d
- 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
- SGR 1806-20: no IR variability of the proposed counterparts
- MASTER:HETE Alert 3259 (SRG1806-20) optical observation
- GRB 040606: Optical observations
- MASTER: HETE Alert 3274 optical observation
- Activivty of SGR 1806-20
- GRB 040511, very fast decay?
- GRB 030324: Detection and Color of Host Galaxy
- GRB 040511: NIR observations with REM
- GRB040511: Candidate optical/NIR afterglow
- GRB 040511: ROTSE-III Rapid Optical Upper Limits
- GRB 040511: Second Epoch Optical Observations
- GRB 040511: Optical observations
- GRB 040511: Optical Observations
- GRB040511: Optical Observations
- GRB040511: Optical Observations
- GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
- IPN triangulation of GRB040425 (=H3183)
- GRB 040423 (=H3175): A Long GRB Localized by HETE
- GRB040422 : I-band follow-up observation at Lulin Observatory
- GRB 040422: ROTSE-IIIb Prompt Optical Limits
- GRB040422, BVRcIc field calibration
- GRB 040422,optical observation
- GRB 040403, deep optical observations
- MASTER: HETE Alert 3163, 3167 technical optical observation
- 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: 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
- 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 ?
- short hard GRB 040322
- GRB040223, improved XMM position
- GRB 031203, possible supernova
- MASTER: RXTE GRB040308 optical observation
- IBAS results on a burst from SGR1806-20
- RXTE GRB040229 optical observation: no candidate
- IPN triangulation of GRB040228 (H3066, H3067)
- GRB040228 : KISO optical follow-up observation
- 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: further offline analysis
- GRB031111, optical observations
- GRB031220: 2nd Chandra observation and X-ray afterglow candidate
- GRB040106: refined X-ray transient position
- GRB 031220: Optical observations of Chandra X-ray sources
- XMM-Newton Images of GRB 040106
- GRB031220: observation at Univercity of Miyazaki
- XMM-Newton observation of GRB040106
- 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
- GRB031225a triangulation (annulus)
- IPN triangulation of GRB031219 (large error box)
- GRB 031220 : Kyoto Optical Observation
- GRB 031220: Subaru observation
- GRB 031220: Optical observation at Tokyo Tech
- 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
- GRB031214 triangulation (annulus), [repost of GCN2487, subject corrected]
- GRB030921 triangulation (annulus)
- XMM-Newton Observations of GRB031203: Preliminary Images
- IPN/HETE localization of GRB031203B (=H2949; large error box)
- GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient