香港天文論壇

2021 January 21 Sun - solar surface in white-light, with AR12797 and AR12798 The sky is 99% cloud-covered today and I go for a walk along the trails of Mt. Parker. Near the end of my walk, the Sun shows up and I hurry home to get some solar images before sunset. I am not surprised that NOAA splits A...

2021 January 20 Sun - solar surface in white-light, with AR12797 I can just capture several images through the cloud. sunspot count: group=1, sunspot=4, R=14 Telescope: Celestron C5, 127mm f/10 Schmidt-Cassegrain Camera : ASI1600MM Pro, not cooled. focal length : 1250 mm f/10 Filters: Baader Solar F...

Images in H-alpha (colour) and in Ca-K

2021 January 19 Sun - prominences on the SW solar limb Sunspot count: group=1, sunspots=4, R=14 For H-alpha images: Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow Camera : ASI174MM and ASI174MC exposure: 20.0 ms (monochrome), 18.0 ms (colour) For Ca-K images: Telescope: Sharpstar AL-80...

Images in H-alpha (colour) and in Ca-K

2021 January 19 Sun - prominences on the SE solar limb Sunspot count: group=1, sunspots=4, R=14 For H-alpha images: Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow Camera : ASI174MM and ASI174MC exposure: 25.0 ms (monochrome), 20.0 ms (colour) For Ca-K images: Telescope: Sharpstar AL-80...

2021 January 19 Sun - prominences on the W solar limb This one is very faint. Sunspot count: group=1, sunspots=4, R=14 For H-alpha images: Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow Camera : ASI174MM and ASI174MC exposure: 20.0 ms (monochrome), 20.0 ms (colour) approximately north ...

2021 January 19 Sun - prominences on the E solar limb

Sunspot count: group=1, sunspots=4, R=14

For H-alpha images:
Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow
Camera : ASI174MM and ASI174MC
exposure: 25.0 ms (monochrome), 20.0 ms (colour)
approximately north is up, east to the left

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2021 January 19 Sun - prominences on the NW solar limb Most of this quiescent prominences is on the backside, leaving just the tips. Sunspot count: group=1, sunspots=4, R=14 For H-alpha images: Telescope: Lunt LS50T with B1200 blocking filter + 2X barlow Camera : ASI174MM and ASI174MC exposure: 25.0...

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Images of AR12797

2021 January 19 Sun - solar surface in H-alpha with AR12796 and AR12797 AR12796 is still active with flares and filaments. All sunspots are gone. AR12797 is active with flares on the solar limb. The large leading sunspots as well as the tiny following ones are visible. There is a huge filament runni...

Images of AR12797

2021 January 19 Sun - solar surface in Ca-K, with AR12796 and AR12797 AR12796 is still active with flares and filaments that are visible in Ca-K. However, the sunspots are gone. AR12797 is active with flares on the solar limb. The large leading sunspots as well as the tiny following ones are visible...