2023 November 18 Sun - prominences on NWW solar limb

[PTS]

2023 November 18 Sun - prominences on NWW solar limb
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A long arch extending towards south is observed in the Ca-K images, but absent in the first H-alpha images which are taken AFTER the Ca-K images. However, the extended arch is again observed in the H-alpha images about 30 minutes later.
Sunspot count ; group=2, sunspot=10, R=30
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Telescope:
Sharpstar AL80 II refractor, ED Triplet. 500 mm f/6.25, with 2X barlow for close-up.
Camera : ASI2600 MM Pro, cooled
Filters:
For Ca-K: Lunt Ca-K Module B1200
For H-alpha: Baader Sundancer II with 3.2X telescentric lens.

approximately north is up, east to the left.

[PTS]

Images in H-alpha

[Eddy So]