SUNSPOT MONITORING – APRIL 23, 2021

Here are today’s solar images taken from Al Sadeem Observatory, April 23, 2021.

The sky was mostly clear with intermittent light to moderate breeze which provided good transparency but average seeing at the time these images were taken. 

Visible solar activity has decreased a bit after the recent departure of AR2817. More C-class intensity solar flares were recorded mainly from the bipolar sunspot groups AR2816 (Cro/beta) which decayed a bit, and AR2817 which is now behind the NW limb over the past 24 hours. The most notable one was a C8.0-class solar flare from AR2817 as recorded by SIDC which is non-Earth directed given its position. Meanwhile, AR2818 (Hsx/alpha) remained stable and inactive. The latest sunspot number (based on visual count and Wolf number calculation) is 25.

Enhanced plages associated with the upper mentioned sunspot groups, few short filaments at the various sections of the Sun’s disk, and huge elongated eruptive ones at the southeastern section of the Sun’s disk and near AR2816, and a few small faint quiescent and moderately huge eruptive prominences mainly at the NW and SE limbs, were the other notable solar features distinctively captured in H-alpha imagery.

Space weather agencies* forecast solar activity to be at low to moderate levels with chances of solar flares of B-class to C-class intensity, mainly from the upper-mentioned active sunspot regions. Close monitoring is being conducted by numerous space weather agencies for any significant development.

Equipment used are Skywatcher 120mm refractor telescope with Baader filter and unmodified Canon EOS 1D Mark IV DSLR camera for visible imagery. For H-alpha imagery, the equipment used are Lunt 60mm H-alpha solar telescope, and QHYCCD 290III mono camera; all mounted on Skywatcher EQ6 pro mount Pre-processing of visible solar images was performed in PIPP, stacking in Autostakkert, slight wavelet adjustments in Registax 6, and post-processing in Adobe Photoshop CC.


*TECHNICAL REPORTS COURTESY OF SOLAR INFLUENCE DATA CENTER (SIDC), NOAA-SPACE WEATHER PREDICTION CENTER (NOAA-SWPC)

Weather Data (5:00 PM – 5:30 PM, April 23, 2021, from NCM Al Wathba Station):

Average Temperature: 39.43°C

Average Humidity: 6.33%

Average Wind Speed and Direction: 17.63 kph from WNW

Average Cloud Cover: 0%

Average Air Pressure: 998.1 hPa

Average Solar Radiation: 240.0 W/m^2

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