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"4572 results found.
- IPN localization of GRB000429
- GRB000418, near-infrared observations
- BeppoSAX GRB000424
- IPN error box for GRB000418
- RE: Budget cuts in BeppoSAX operations: impact on GRB observation
- Budget cuts in BeppoSAX operations: impact on GRB observations
- GRB000408 [IPN Position]
- GRB000301C - B and R photometry
- GRB 000301C: HST/STIS CCD Imaging of the field
- HST Observations of GRB 990712
- SAX_WFC_GRB_NOTICE
- GRB 000131 Optical Observations
- IPN error boxes for GRB991229
- IPN error box for GRB991216
- GRB991216, optical observations
- GRB991208, optical observations
- GRB 991106, optical observations
- GRB991106, near-infrared observations
- GRB 991106, radio observations
- GRB 991014 - BeppoSAX NFI observations
- IPN localization of GRB990907
- BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
- GRB 990712, Optical Observation
- GRB 990712 Optical Decay: Indication of Bright Host Galaxy
- GRB 990712
- BeppoSAX: GRB990625
- X-ray/GRB 1SAX J0835.9+5118, Optical Observation
- GRB990506 observation plan
- Refined IPN error box for GRB990506
- GRB 990506, armchair astronomy
- ASM/IPN error box for GRB 990308 (BATSE #7457)
- GRB990308 (Trig. 7457), optical observations
- Optical Observations of GRB990217
- GRB990123 observations
- GRB 990123: Reduced HST Images
- GRB990123, is the "radio flare" due to an inhomogeneous medium?
- GRB 990123: New Constraints on Possible Foreground Galaxies
- GRB990123 Optical Observations
- GRB 990123: Detection of the IR Transient, and the Light Curve Fits
- GRB 990123: Continued Radio Observations
- Search for Potential Images of GRB 990123
- GRB990123, Optical BVRI Observations
- GRB 990123: near-infrared observations.
- GRB990123: NIR Observation
- "GRB 990123: New BV Observations"
- GRB990123 Optical Observations
- GRB981220
- GRB 981220 Optical observations
- GRB 981220 and GRB 981226, optical observations
- GRB 981226 optical observations
- GRB981220 B, R and I band observations
- GRB 981226 - Infrared Observations
- GRB 981220
- GRB981220 I-band Observations
- GRB980425 Optical Follow-up
- GRB980613 Optical Observations
- SGR 1627-41
- GRB980519 optical observations
- GRB 980519 Optical Observations
- GRB 980425 Brightness Temperature
- GRB980329, Fading IR counterpart to radio source
- Near-IR follow-up on GRB 971227
- GRB971214: Keck R & I-band Observations
- Optical Observations of the GRB 971227 field
- GRB971227: Plaskett R-band observations
- GRB971227: Further CAHA R-band images
- GRB 971214: KPNO Optical Observations
- Optical Observations of GRB 971214 at Keck
- GRB 971214: Optical Observations
- GRB 971024: Refined analysis by USNOFS Observations
- GRB 971024: USNO Observations
- GRB 970228: Keck/LRIS Optical Observations