香港天文論壇

Images of filaments near SE limb

Images of AR12818

Images of AR12817

Images of AR12816

2021 April 21 Sun - solar surface in H-alpha, with AR12815, AR12816, AR12817 and AR12818 AR12815 is close to the SE limb at (S21W77). Faint plages and filaments are still visible. 2 small prominences are observed to grow from this AR, and produces an interesting eruption. (I'll post this later) AR12...

Images of AR12818

Images of AR12817

2021 April 21 Sun - solar surface in Ca-K, with AR12815, AR12816, AR12817 and AR12818 No image of AR12815 is taken. AR12816 is today located at (S24E08). This group has been very active in the past 24 hours. At least 8 sunspots are visible, many come with penumbrae. The plages and large sunspots are...

Images of AR12818

Images of AR12817

Images of AR12816

2021 April 21 Sun - solar surface in white-light, with AR12815, AR12816, AR12817 and AR12818 AR12815 is close to the SE limb, at (S21W77). No sunspot is visible. AR12816 is today located at (S24E08). This group has been very active in the past 24 hours. At least 8 sunspots are visible, many come wit...

2021 April 21 Sun - AR12815, AR12816, AR20817 and AR12818 AR12815 is located at (S21W77). No sunspot is visible. AR12816 is today located at (S24E08). This group has been very active in the past 24 hours. At least 8 sunspots are visible, many come with penumbrae. A M1.1 flare shows up yesterday. AR1...

2021 April 20 Sun - solar surface in white-light, with AR12815, AR12816, AR12817 and possible AR12818 and possible AR12819 AR12814 has turned to the backside. AR12815 has no sunspot. A patch of faculae is visible. AR12816 is very active, with 4 sunspots that come with penumbrae. AR12817 is very acti...

2021 April 20 Sun - AR12814, AR12815, AR12816, AR20817 and possible AR12818 and possible AR12819 AR12814 is now located at (S22W87). The activities of this group has subsided, and no sunspot is visible. AR12815 is located at (S21W63). No sunspot is visible. AR12816 is today located at (S24E21). This...