:Issued: 2026 Jan 24 1025 UTC
:Product: documentation at http://www.sidc.be/products/presto
#--------------------------------------------------------------------#
# FAST WARNING 'PRESTO' MESSAGE  from the SIDC (RWC-Belgium)         #
#--------------------------------------------------------------------#
Two halo coronal mass ejections (CMEs) were automatically detected by the CACTus tool
over the past 24 hours. The first event was first detected on 2026 Jan 23 at 15:12
UTC, with a central position angle near 141 degrees, an angular width of about 180
degrees, and a projected speed of roughly 600-700 km/s. No clear source signature was
identified on the visible solar disk, and the event is therefore considered likely
backside. A second event was first detected on 2026 Jan 23 at 22:35 UTC, with a
central position angle near 123 degrees, an angular width of about 208 degrees, and a
projected speed of roughly 800-900 km/s. The CME appears to originate just behind the
limb, as associated coronal dimming extended up to the visible disk. Given this
geometry, the CME is also considered likely backside, with no Earth-directed
component expected.
#--------------------------------------------------------------------#
# Solar Influences Data analysis Center - RWC Belgium                #
# Royal Observatory of Belgium                                       #
#                                                                    #
# Website         http://www.sidc.be.                                #
# E-mail          sidc-support@oma.be                                #
# To unsubscribe  http://www.sidc.be/registration/unsub.php          #
#                                                                    #
# Legal notices:                                                     #
# - Intellectual Property Rights:                                    #
#   http://www.astro.oma.be/common/internet/en/data-policy-en.pdf    #
# - Liability Disclaimer:                                            #
#   http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf     #
# - Use and processing of your personal information:                 #
#   http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf #
#--------------------------------------------------------------------#