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"
3821 results found.
- Short RXTE/ASM transient 020406; may be a GRB
- XRF/GRB 011030: Detection of the Probable Host Galaxy
- IPN detection and localization of Cygnus X-1 flares
- RXTE Observations of SGR 1900+14
- SGR1900+14 activity
- IPN/HETE Detection of Bursts from SGR1900+14
- IPN Upper Limits to a GRB Associated With SN2002ap
- IPN detection of further activity from SGR1806-20
- Optical observation of SGR 1806-20 at the 6-m SAO telescope
- GRB010923 as seen by BeppoSAX GRBM
- HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
- Probable SGR or Short Duration GRB Detected by HETE
- Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
- GRB 010629 Optical Observations
- GRB010629: A Burst Localized by HETE
- Possible burst from SGR1806-20
- IPN detection of SGR1900+14
- X-ray precursors to the large flare from SGR 1900+14
- SGR 1900+14: No evidence of extended X-ray emission
- SGR 1900+14 : RXTE observations
- BeppoSAX/NFI Follow-up Observation of SGR 1900+14
- SGR1900+14
- SGR 1900+14: Correction to GCN 1049
- Millimeter observation of SGR 1900+14
- SGR 1900+14: Detection of extended X-ray emission
- Chandra Observations of SGR 1900+14
- SGR 1900+14, Chandra observations
- Chandra Observations of SGR 1900+14
- SGR1900+14, I-band observations
- GRB 980326: Late-time HST/STIS observations
- GRB 010214, I-band data
- GRB010214 Optical Observation
- GRB010126 optical observations
- Optical Observations of GRB 001018 at Keck
- IPN triangulation of GRB001219
- GRB 001109: deep JHK upper limits
- IPN TRIANGULATION OF GRB001105
- IPN TRIANGULATION OF GRB001020
- GRB 000926 Chandra Observation
- GRB000926 K'-band Observation
- HST/STIS observations of the host galaxy of GRB 980329
- SGR 1806-20 burst activity
- IPN localization of GRB000730B
- IPN localization of GRB000730B
- GRB 990510: Possible detection of a host galaxy
- GRB 990510 Host Galaxy Discovery
- GRB 990712: Late time HST/STIS Observations
- GRB 000630: Detection of the Optical Afterglow
- GRB000616 [IPN Position]
- GRB 000418: Detection of the Host Galaxy
- GRB000529: BeppoSAX NFI follow-up preliminary analysis
- GRB000529: BeppoSAX WFC position
- GRB000528: BeppoSAX GRBM observations
- GRB000419 [IPN Position]
- RE: Budget cuts in BeppoSAX operations: impact on GRB observation
- GRB 000326: Optical Observations
- GRB 000301C, Optical Observation
- GRB000301C
- GRB 000301C : Optical Candidate
- GRB000226 [IPN Position]
- HST Observations of GRB 990712
- IPN annulus for GRB000214
- GRB000126, optical observations
- IPN localization of GRB000126
- GRB991216 late optical observation
- BEPPOSAX GRBM Localization of GRB991226
- IPN error boxes for GRB991229
- IPN localization of GRB991226
- IPN localization of GRB991208
- IPN localization of GRB991014 - CORRECTION
- IPN localization of GRB991014
- BATSE GRB trigger criteria
- GRB 990712 Late Optical Decay and Host Galaxy
- GRB 990712, Optical Observation
- GRB 990712
- IPN localization of GRB990705
- BeppoSAX NFI Observation of GRB990627 X-ray afterglow
- X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
- GRB 990510: optical observations
- GRB 990510: optical observations
- GRB990510: X-ray afterglow
- GRB 990510: optical observation
- GRB 990510: Broad Band Break
- GRB990510: optical observation
- GRB 990510 Optical Observations
- GRB 990510 optical observations
- GRB990510 optical observations
- GRB990510
- GRB 990510 optical observations
- GRB 990510 optical observations
- GRB 990510 optical observations
- IPN localization of GRB990510
- New IPN/RXTE error box for GRB990506
- GRB990308 not a new SGR
- GRB990308, Possible new SGR~0209+70
- GRB 990123: Discovery of the Probable Host Galaxy
- Possible identification of SN1999E with GRB980910
- GRB 981226: radio variable
- GRB 981226 Optical Observations
- GRB981226, sub-millimeter observations