香港天文論壇

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2019 Jan 22 comet C/2018 Y1 Iwamoto at Hokoon C/2018 Y1 is very diffuse, and faint. Telescope: 50-cm RC reflector f/8 camera: ASI1600MM Pro (cooled to -20C) exposure : 8 s time: 19:04:06 UTC and 20:44:16 UTC Note the rapid movement during the 100 minutes between the 2 images. south is up, east to th...

2019 Jan 22 comet 38P/ Stephan-Oterma at Hokoon

Telescope: 50-cm RC reflector f/8
camera: ASI1600MM Pro (cooled to -20C)
exposure : 12 s
time: 17:09:16 UTC and 17:36:08 UTC
south is up, east to the left

2019 Jan 22 comet 46P/ Wirtanen at Hokoon

Telescope: 50-cm RC reflector f/8
camera: ASI1600MM Pro (cooled to -20C)
exposure : 12 s
time: 16:37:19 UTC and 16:52:11 UTC
south is up, east to the left

another image

2019 Jan 22 comet 64P/ Swift-Gehrels at Hokoon

Telescope: 50-cm RC reflector f/8
camera: ASI1600MM Pro (cooled to -20C)
exposure : 20 s
time: 13:40:25 UTC and 13:54:27 UTC
blink the 2 images to see its movement in 14 minutes
estimated magnitude: 16.2
south is up, east to the left

2019 Jan 22 Uranus & satellites at Hokoon

Telescope: 50-cm RC reflector f/8
camera: ASI1600MM Pro (cooled to -10C)
exposure : 8 s
time: 13:10:57 UTC
cropped 800x600
south is up, east to the left

reminder

Asteroid occultation event on 2019 March 03 I've prepared finder charts from: Digital Sky Survey (15 x 15 arcmin and 30 x 30 arcmin) and The Sky 6 (15x11 arcmin) IOTA/IOTA-ES occultation update for (2) Pallas / TYC 0323-01028-1 event on 2019 Mar 03, 19:42 UT Visible from Russia, China, Indonesia, W ...

reminder

reminder

Amateur Telescope Making - Book 1 - In memory of an old friend, Dr. Lau Tai Chi. One day in 1969, I was in Cat Street, looking for a pair of binocular objectives to make an eyepiece for my newly finished 6-inch f/5 newtonian. While waiting for the shopkeeper to find the lens, an elderly gentleman as...

Sun, Moon and Mars

Date: 2019 Jan 12
Camera: Sony RX10 IV
Lens: Zeiss Sonnar 8.8-220 mm f/2.4-4 (24-600 mm 35-mm equivalent)

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