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"26170 results found.
- GRB 991105: BATSE Observations
- GRB991106, optical observation at SAO-RAS
- GRB 991106, LOTIS Optical Observations
- GRB991105: SAX-GRBM/-WFC detection
- BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
- GRB ALERT: GRB991105
- GRB 991014 - BeppoSAX NFI observations
- GRB991014 BATSE Observations
- Super-LOTIS optical observation of GRB991014
- BeppoSAX ALERT: GRB991014
- GRB 990915 optical observations
- BATSE GRB trigger criteria
- IPN error box for GRB990915 (=BATSE 7766)
- IPN localization of BATSE #7766 (GRB990915)
- GRB990806: BATSE Observations
- BeppoSAX ALERT GRB990806: Summer GRB
- BeppoSAX NFI Observation of GRB990705
- BeppoSAX NFI Observation of GRB990705
- GRB990704
- BeppoSAX NFI Observation of GRB990627 X-ray afterglow
- BeppoSAX: GRB990625
- GRB 990506 Radio Transient
- X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
- optical observation of the X-ray/GRB transient SAX J0835.9+5118
- BeppoSAX: A new fast X-ray transient
- GRB990510: X-ray afterglow
- GRB 990510: BATSE Observations
- GRB 990510: BeppoSAX/GRBM observations
- GRB 990506 Radio Observations
- GRB 990506: BATSE Observations
- GRB990323 PRECISE IPN POSITION
- GRB990316: simultaneous optical observation
- GRB990316 - Optical null results
- ASM/IPN error box for GRB 990308 (BATSE #7457)
- GRB 990308a and GRB 990308b
- GRB990308 (Trig. 7457), optical observations
- BATSE Resumes Normal Operations
- GRB990217: BeppoSAX/GRBM data
- Search for Potential Images of GRB 990123
- Search for Potential Images of GRB 990123
- GRB990123, OSSE observations
- GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
- GRB 990123: BATSE Observations
- GRB990123, early optical counterpart detection
- GRB990123, BeppoSAX-NFI X-ray afterglow detection
- GRB990123, BeppoSAX WFC detection and NFI planned follow-up
- Possible identification of SN1999E with GRB980910
- GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
- GRB 980923 BATSE Observations
- SGR1900+14, BeppoSAX-GRBM observations
- GRB980703 - BeppoSAX/GRBM detection
- GRB 980703: BATSE Observations
- RXTE Observation of GRB 980706
- GRB980703: LOTIS observation at early times
- GRB 980703: ASM Position & Intensity
- GRB 980613: BATSE Observations
- SGR1627-41, BeppoSAX-GRBM detections
- Discovery of a new SGR source, SGR1627-41
- BATSE on-board GRB trigger change
- GRB980519 BATSE Observations
- BATSE on-board GRB trigger change
- GRB980519, BeppoSAX-WFC updated position
- GRB980519, BeppoSAX-WFC position
- GRB980425 BATSE observations
- report on BSAX observations of GRB980425
- GRB980326 IPN annulus
- GRB980329 IPN annulus
- GRB 971024: Refined analysis by USNOFS Observations
- GRB 971024: USNO Observations
- GRB 970925: BATSE Localization