The SIDC is part of the Royal Observatory of Belgium and a partner in the Solar Terrestrial Center of Excellence (STCE).


Two, out of several, sunspot groups observed on the visible side of the
solar disc have during last 24 hours increased the complexity of their
photospheric magnetic field configuration. Catania sunspot groups 87 and 86
(NOAA ARs 2816 and 2817) have presently beta configuration of their
photospheric magnetic field. 
During last 24 hours 17 B-class and one M-class flare were reported,
majority of them originating from the Catania sunspot group 86 (NOAA AR
2817). The M1.1 flare observed on April 19 (peaked at 23:42 UT), have
originated from the Catania sunspot group 87 (NOAA AR 2816) which is
presently still increasing the area and sunspot numbers. During coming
hours we can expect B-class flares, and isolated C-class flares. The
M-class flares are still possible but not very probable.
The M 1.1 flare was associated with the EUV wave, coronal dimming, type II
radio burst (indicating presence of a shock wave), and a rather diffuse
CME. The CME had angular width of about 100 degrees and projected line of
the sight speed of about 500 km/s (as reported by CACTUS software).
Although the CME is not very wide, its source region is situated close to
the solar disc center and the glancing blow still might be expected at
Earth on April 23, although this is not very probable.
During last 24 hours the proton flux levels remained at background values.

The greater than 2MeV electron flux still remains above the 1000 pfu
threshold, and it is expected to remain above the threshold for long
periods throughout April 20. The 24h electron fluence is at moderate levels
and is expected to be in the range of moderate to high levels in the next
24 hours.

Earth is still inside the fast solar wind with the speed of about 590 km/s.
The interplanetary magnetic field magnitude is 4 nT. 
Small, negative polarity equatorial coronal hole has reached central
meridian this morning. The associated fast solar wind can be expected at
Earth on April 23.
Due to longer interval of the negative value of the Bz component of the
interplanetary magnetic field, active geomagnetic conditions were reported
in the evening of April 19 (from about 19 until 23 UT). The local station
at Dourbe reported Kp=4 and NOAA reported K=4.
Presently the geomagnetic conditions are quiet and we expect them to stay
so in the coming hours.

Latest SWAP image

SWAP latest image

Latest USET H-alpha image
USET latest Halpha image

Latest LYRA curve

Latest LYRA Curves

Latest Callisto Observations

Latest HUMAIN Callisto qkl

Daily estimated sunspot number

Most recent alerts

2021 Apr 15 0946 UTC
END OF ALL QUIET ALERT ...................... The SIDC [more]

2021 Apr 14 0853 UTC
A faint and slow partial halo CME is observed by LASCO C2 and C3 coronagraphs [more]

2021 Mar 18 0131 UTC
A halo or partial-halo CME was detected with the following characteristics: [more]

2017 Sep 10 1650 UTC
A class X8.9 solar X-ray flare occurred on 2017/09/10 with peak time 16:06UT [more]