Seiichi Yoshida's Diary of Comet Observations (2025)
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Updated on September 27, 2025 |
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2025 Sept. 21 (5 comets) |
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I observed 5 comets visually on Sept. 21, in Kita-karuizawa, Gunma, Japan.
Although it was almost cloudy in the evening, the weather became find very rapidly during the twilight. Mars in the low sky was easily visible. But unfortunately, C/2025 R2 ( SWAN ) was behind the mountains and I could not see it.
Then clouds came again, and I could not see the interstellar comet 3I/ATLAS, either.
The weather was find and clear in the morning.
C/2022 N2 ( PanSTARRS )
14.0 mag Dia. 0.8' DC 3 (40.0-cm reflector 144x)
Faint and small.
C/2024 E1 ( Wierzchos )
13.1 mag Dia. 1.3' DC 3-4 (40.0-cm reflector 144x)
Easier to see than expected.
C/2025 A6 ( Lemmon )
8.5 mag Dia. 4.0' DC 6 (40.0-cm reflector 36x)
8.1 mag Dia. 5' DC 7 (10x70 monocular)
Bright and easily visible!
240P/NEAT
14.2 mag Dia. 0.5' DC 2 (40.0-cm reflector 257x)
Diffuse, hard to see.
414P/STEREO
fainter than 12.6 mag Dia. 0.5' (40.0-cm reflector 144x)
It located near Venus and easy to guide the telescope. But the comet was not visible.
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I observed C/2024 G3 ( ATLAS ) visually on Jan. 16 in Katahama coast, Numazu City, Shizuoka, Japan.
Finally I could see Comet C/2024 G3 ( ATLAS )! It looks cool, bright sharp comet in the evening dusk sky. I succeeded to take the photo with my smart phone.
There are large clouds in the west. I could see the comet only during three minutes, from 17:33 when the comet appeared from the cloud, to 17:36 when the comet set in the horizon. It was very lucky there was narrow clear sky between clouds and horizon.
C/2024 G3 ( ATLAS )
about -1.5 mag DC 8 Tail 0.3 deg (p.a. 75 deg) (10x66 monocular)
I estimated the brightness using Altair and gamma Aql. The comet was -1.5 mag, the second brightest comet in my life next to C/2006 P1 ( McNaught ). However, in my impression, Comet Tsuchinshan-ATLAS last year was much greater.
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Go to Seiichi Yoshida's Diary of Comet Observations in 2024. |