Comet 3I ATLAS on early morning of Nov 22, 2025


Date & Time: Nov 21 2025, from 28:15 to 28:52 JST(+0900)
Composed 10 shots with 4 minutes exposed
Optical: Meade 25cm(10") Schmidt-Cassegrain with conversion lens (f=1600mm, F6.3)
with IDAS LPS-P1 Light-pollution suppression filter
Auto-guided with Meade LX200 Equatorial & Lacerta M-GEN
Digital Camera: Nikon D810A
Location: Ooizumi, Hokuto city, Yamanashi pref.

Camera Settings: Recording Format...14bit CCD-RAW, converted to 16bit TIFF(4080×4080)
Device Size...20×20mm
Sensitivity...ISO4000, White Balance...Daylight


The third interstellar comet in history, comet 3I ATLAS, was located in the eastern low sky before dawn on this day, about 2.5 degrees WSW of γ Virginis, and a 10th-magnitude coma was observed. No prominent tail was detected, giving it the appearance of a typical small comet. It passed perihelion at the end of Oct and is now heading back out of the Solar System. It will remain observable under favorable conditions from Japan for a while, but it is expected to fade rapidly.
View angle: 0.70×0.70°


2025T1 ATLAS on Nov 23, 2025

Copyright(c) 2025 by Naoyuki Kurita, All rights reserved.
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