2021 April 22 Sun - solar surface in Ca-K, with AR12816, AR12817 and AR12818

[PTS]

2021 April 22 Sun - solar surface in Ca-K, with AR12816, AR12817 and AR12818

AR12816 has crossed the meridian, and is today located at (S24w08). This group has been very active in the past 24 hours. 6 sunspots are visible, some come with penumbrae. This Class-E group extends more than 10 degrees in longitude. The plages are well-resolved.
AR12817 is very close to the, solar limb and is located at (N18W81). This Class-D group has at least 8 sunspots. C1.5 flares are observed between the leading and following sunspots.
AR12818 is near the SE limb, at (S17E50). A large sunspot with penumbrae is visible. Bright plages are observes, mostly to the SE.
sunspot count: group=3, sunspot=15, R=45

Telescope: Sharpstar AL-80 II, 8 cm f/6.25 APO refractor
Camera : ASI174MM
focal length : 500 mm f/6.25
filter: Lunt Ca-K Module B1200
approximately north is up, east to the left.

[PTS]

Images of AR12817

[PTS]

Images of AR12818

[Eddy So]