Saturday, January 31
Although we usually have many days with clear sky from October to December, there were fewer clear skies last year. However, in January I conducted comet hunting 10 times thanks to sudden increase in clear skies. Especially, I comet hunted six consecutive days at predawn from January 14 through 19. There were some more moonless starry nights other than the days I conducted the hunting sessions, but I was to fatigue to search.
On Thursday, January 1, I observed three comets, 3I ATLAS, 29P Schwassmann-Wachmann, and 24P Shaumasse. The transparency was poor on Saturday, 17, which exacerbated light pollution, especially, emitted from Nobeoka City, some 55 km southeast from the observation site. Even if it were not for it, light pollution becomes worse in the past few years due to rapid development in Kikuyo town and Ozu town, east of Kumamoto City, because Tiwan Semiconductor Manufacturing Company (TSMC) has established.
Moon rose during taking down my telescope on Saturday, January 17. The sky was red due to yellow sand from the continent.
On a warm day air temperature was +5°C, while when cold wave came it was as low as -9°C that was the same with the record low at the site. Nonetheless, perceived temperature cannot be determined by the air temperature alone. One feels colder at near 0°C with wind than at -9°C (Monday, Jan. 26) with windless. On Monday, January 26 the amount of snow was large. The depth was around 10 cm at the place where snowmelt has not yet melted.
After completed the comet hunting session on Monday, Janudary 26. Beyond remaining snow, the majestic mountain, Mt. Sobosan, came into view.
On Wednesday, January 28, I started comet hunting with M12, a globular cluster in the constellation of Ophiuchus. After that, M10 and M14 came into the FOV. The next deep sky object I identified was NGC6353! This globular cluster with the magnitude of 9.3 is a memorable celestial object identified just before the discovery of C/2002 E2 Snyder-Murakami. At the time of discovery, I captured another globular cluster, NGC6426, with the magnitude of 10.9, but I overlooked it this session. Although the altitude above the horizon for NGC6426 at the hunting session this time was about 26° that was sufficiently high, I overlooked. The cause was poor transparency and light pollution. If a new comet that had the same appearance and brightness with C/2002 E2 had been in the area of searching, I could not have detected it.
The next object came into the FOV was NGC6712, a globular cluster in the constellation of Scutum. I spotted a possible new comet of 7th magnitude near this cluster on February 26 in 2004, while I was seeping the sky using 15x110 mm binocular. However, it disappeared in the twilight before I confirmed the motion. I believe the object must be a NEO. I reported the discovery, but the next day no one in the world including me could observe the object.
Open cluster, IC4665, in the constellation of Ophiuchus. The image is 60' wide.