香港天文論壇

Images of AR12864 and AR12865

2021 September 09 Sun - solar surface in Ca-K, with AR12863, AR12864, AR12865, AR12866, AR12868, AR12869 and possible AR12870. AR12863 is located at (S16W54). The large sunspot with its penumbra is visible. A huge patch of plages is following. AR12864 is located at (N24W45). A large sunspot, togethe...

Images of possible AR12870

Images of AR12869

Images of AR12868

Images of AR12866

Images of AR12864

2021 September 09 Sun - solar surface in white-light, with AR12863, AR12864, AR12865, AR12866, AR12868, AR12869 and possible AR12870. AR12863 is located at (S16W54). In addition to the large sunspot, a small one is visible to its east. A huge patch of faculae is following. AR12864 is located at (N24...

AAVSO webinar

Title:
Using AAVSO's Exoplanet Database for Reporting and Retrieving Exoplanet Observations

Speaker:
George Silvis (AAVSO Bright Star Monitor Section)

Date: 2021 September 12, Saturday
Time: 18:00 UT
See:
https://www.aavso.org/2021-webinars-july-september

Images in H-alpha

2021 September 08 Sun - prominences on the NEE solar limb. Sunspot count: group=5, sunspot=50, R=100 For H-alpha images: Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow Camera : ASI1600MM Pro, not cooled. exposure: 25.0 ms For Ca-K images: Telescope: Sharpstar AL-80 II, 8 cm f/6.25 APO ...

Images of AR12866, AR12868 and possible AR12869

Images of AR12864 and AR12865

2021 September 08 Sun - solar surface in H-alpha, with AR12863, AR12864, AR12865, AR12866, AR12868 and possible AR12869. AR12863 is located at (S17W42). The large sunspot, with its penumbra and penumbral fibrils, is visible. Flare has subsided. A dark filaments runs eastward from the sunspot. AR1286...

Images of AR12868 and possible AR12689