Seiichi Yoshida's Diary of Comet Observations (2015)

Japanese version Home page

Updated on November 24, 2015

Go to Seiichi Yoshida's Diary of Comet Observations in 2016.

2015 Nov. 20 (5 comets) I observed 5 comets visually on Nov. 20 in Kita-karuizawa, Gunma, Japan. It was cloudy in the evening, but it became fine with few clouds at night. C/2013 X1 ( PanSTARRS ) 10.9 mag   Dia. 2.0'   DC 7   (40.0-cm reflector 75x) Small, but strongly condensed and bright. It located near by open cluster M34. C/2014 S2 ( PanSTARRS ) 8.8 mag   Dia. 4.5'   DC 6-7   (40.0-cm reflector 36x) Very bright and easy to see. C/2014 W2 ( PanSTARRS ) 12.4 mag   Dia. 1.1'   DC 5   (40.0-cm reflector 144x) Small, but easily visible. 67P/Churyumov-Gerasimenko 12.5 mag   Dia. 1.6'   DC 3   (40.0-cm reflector 144x) It became faint and hard to see. 230P/LINEAR fainter than 15.4 mag   (40.0-cm reflector 257x) Because it looks stellar by CCD images, I thought it could be visible visually. But it was not visible. It located near by Rigel and easy to guide the telescope to the field.

2015 Oct. 11 (5 comets) I observed 5 comets visually on Oct. 11 in Kita-karuizawa, Gunma, Japan. It was rainy in the morning, and it kept cloudy all through the afternoon, but it became fine with few clouds at night. C/2013 X1 ( PanSTARRS ) 13.1 mag   Dia. 0.8'   DC 6   (40.0-cm reflector 144x) Small, but very strongly condensed and easy to see. It located near by double stars. C/2014 S2 ( PanSTARRS ) 9.7 mag   Dia. 5.0'   DC 7   (40.0-cm reflector 36x) Strongly condensed, bright, and easy to see. Sharp star-like central nuclear is evident with a x75 magnification. It located near by Polaris. C/2015 F4 ( Jacques ) 13.2 mag   Dia. 0.9'   DC 5   (40.0-cm reflector 144x) Unexpectedly it is visible well still now. C/2015 G2 ( MASTER ) 14.5 mag   Dia. 0.4'   DC 2   (40.0-cm reflector 257x) Near limit. 67P/Churyumov-Gerasimenko 13.0 mag   Dia. 1.0'   DC 3   (40.0-cm reflector 144x) Much fainter than expected, not easy to see. Maybe the comet has faded.

2015 Sept. 20-21 (7 comets) I observed 7 comets visually on Sept. 20 and 21 in Kita-karuizawa, Gunma, Japan. The weather was fine, but it tends to be cloudy at night. I could see the stars during only a few hours. On Sept. 21, a comet observer Takamatsu-san came and talked together. C/2013 X1 ( PanSTARRS ) Sept. 21   12.5 mag   Dia. 1.0'   DC 4   (40.0-cm reflector 144x) Much brighter than expected. C/2014 Q2 ( Lovejoy ) Sept. 20   11.3 mag   Dia. 1.6'   DC 3   (40.0-cm reflector 75x) Still easy to see. It located near by Hercules Cluster M13. C/2014 S2 ( PanSTARRS ) Sept. 20   11.1 mag   Dia. 1.4'   DC 4   (40.0-cm reflector 144x) Sept. 21   10.8 mag   Dia. 2.0'   DC S6   (40.0-cm reflector 75x) On Sept. 20, it looked very bright with higher magnification, but not easy to see with lower magnification. On Sept. 21, I felt it became much brighter with a star-like sharp central condensation, which I could not see on the previous day. So I thought it might brightened in outburst. 67P/Churyumov-Gerasimenko Sept. 21   11.1 mag   Dia. 1.6'   DC 5   (40.0-cm reflector 144x) Very bright and easy to see. 88P/Howell Sept. 21   13.2 mag   Dia. 1.3'   DC 2   (40.0-cm reflector 144x) It became faint, but it looks large and diffuse. 141P/Machholz 2 Sept. 21   11.8 mag   Dia. 1.1'   DC 1   (40.0-cm reflector 144x) The sky became cloudy temporarily, but it became fine rapidly while the sky was getting brighter. So I could see the comet. It located near by Venus, so I also enjoyed the large Moon-like Venus. 205P/Giacobini Sept. 21   13.7 mag   Dia. 0.4'   DC 4   (40.0-cm reflector 257x) Tiny.

2015 May 1-2 (5 comets) I observed 5 comets visually on May 1 and 2 in Kita-karuizawa, Gunma, Japan. The weather was fine, but the sky was not so transparent due to the full moon. I also enjoyed the rendezvous of Mercury and Pleiades in the evening on May 1. C/2014 Q2 ( Lovejoy ) May 1   7.5 mag   Dia. 7.5'   DC 7   (40.0-cm reflector 36x) May 2   7.9 mag   Dia. 6.5'   DC 6-7   (40.0-cm reflector 36x) Strongly condensed and easy to see. C/2015 C2 ( SWAN ) May 1   about 11.0 mag   Dia. 1.0'   DC 2   (40.0-cm reflector 144x) Hard to see due to the low sky. C/2015 F3 ( SWAN ) May 1   12.7 mag   Dia. 1.4'   DC 2   (40.0-cm reflector 144x) Tiny and diffuse. The full moon was about to set under the horizon, so the influence was less. C/2015 F5 ( SWAN-Xingming ) May 1   about 11.6 mag   Dia. 1.5'   DC 1   (40.0-cm reflector 144x) May 2   fainter than 12.0 mag   Dia. 1.0'   (40.0-cm reflector 144x) Hard to see due to the full moon. 88P/Howell May 2   10.2 mag   Dia. 1.2'   DC 2-3   (40.0-cm reflector 144x) Hard to guide my telescope due to the low sky condition. Maybe the comet extends larger.

2015 Mar. 2 (1 comet) I observed C/2014 Q2 visually on Mar. 2 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 5.4 mag   Dia. 7'   DC 3   (10x66 monocular) The comet became faint, near limit in the city light pollution. This will be my final observation of C/2014 Q2 at this location.

2015 Feb. 15 (1 comet) I observed C/2014 Q2 visually on Feb. 15 beside Tsurumi River in Yokohama City, Kanagawa, Japan. Strong wind. C/2014 Q2 ( Lovejoy ) 4.7 mag   Dia. 16'   DC 6   (10x66 monocular) The comet looks bright and strongly condensed.

2015 Feb. 14 (1 comet) I observed C/2014 Q2 visually on Feb. 14 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 5.0 mag   Dia. 15'   DC 5   (10x66 monocular) It keeps bright much longer than expected.

2015 Feb. 10 (1 comet) I observed C/2014 Q2 visually on Feb. 10 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.7 mag   Dia. 13'   DC 5   (10x66 monocular)

2015 Feb. 9 (1 comet) I observed C/2014 Q2 visually on Feb. 9 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.4 mag   Dia. 15'   DC 5   (10x66 monocular) The comet may have brightened.

2015 Feb. 8 (1 comet) I observed C/2014 Q2 visually on Feb. 8 beside Tsurumi River in Yokohama City, Kanagawa, Japan. It had been rainy all day. But the sky became fine with no clouds very quickly in the evening. C/2014 Q2 ( Lovejoy ) 4.8 mag   Dia. 14'   DC 4-5   (10x66 monocular)

2015 Feb. 3 (1 comet) I observed C/2014 Q2 visually on Feb. 3 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.7 mag   Dia. 12'   DC 4-5   (10x66 monocular) It became small.

2015 Feb. 2 (1 comet) I observed C/2014 Q2 visually on Feb. 2 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.8 mag   Dia. 14'   DC 4-5   (10x66 monocular)

2015 Feb. 1 (1 comet) I observed C/2014 Q2 visually on Feb. 1 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.7 mag   Dia. 15'   DC 4   (10x66 monocular) Hard to see in the city light pollution.

2015 Jan. 31 (1 comet) I observed C/2014 Q2 visually on Jan. 31 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.7 mag   Dia. 16'   DC 5   (10x66 monocular) Large moon exists, but the sky is very clear. However, the comet became much fainter than before.

2015 Jan. 28 (1 comet) I observed C/2014 Q2 visually on Jan. 28 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.2 mag   Dia. 16'   DC 5-6   (10x66 monocular) Near the half moon, but the sky is clear and the comet looks bright.

2015 Jan. 24 (1 comet) I observed C/2014 Q2 visually on Jan. 24 beside Tsurumi River in Yokohama City, Kanagawa, Japan. The weather had been cloudy all day. But it suddenly became fine with no clouds at night. C/2014 Q2 ( Lovejoy ) 4.3 mag   Dia. 19'   DC 5   (10x66 monocular)

2015 Jan. 23 (1 comet) I observed C/2014 Q2 visually on Jan. 23 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.5 mag   Dia. 17'   DC 6   (10x66 monocular) The sky is very clear today, and the comet looks bright well.

2015 Jan. 20 (1 comet) I observed C/2014 Q2 visually on Jan. 20 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.3 mag   Dia. 16'   DC 5   (10x66 monocular) I felt the comet got faint, maybe due to the sky condition.

2015 Jan. 19 (1 comet) I observed C/2014 Q2 visually on Jan. 19 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.0 mag   Dia. 18'   DC 6   (10x66 monocular)

2015 Jan. 18 (1 comet) I observed C/2014 Q2 visually on Jan. 18 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.0 mag   Dia. 20'   DC 5-6   (10x66 monocular) Through thin clouds, but it looks almost same as previous day.

2015 Jan. 17 (1 comet) I observed C/2014 Q2 visually on Jan. 17 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 3.9 mag   Dia. 23'   DC 5-6   (10x66 monocular)

2015 Jan. 13 (1 comet) I observed C/2014 Q2 visually on Jan. 13 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 3.8 mag   Dia. 22'   DC 6   (10x66 monocular) The comet seems to have brightened furthermore.

2015 Jan. 12 (1 comet) I observed C/2014 Q2 visually on Jan. 12 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.0 mag   Dia. 21'   DC 6   (10x66 monocular)

2015 Jan. 11 (1 comet) I observed C/2014 Q2 visually on Jan. 11 beside Tsurumi River in Yokohama City, Kanagawa, Japan. C/2014 Q2 ( Lovejoy ) 4.3 mag   Dia. 20'   DC 5   (10x66 monocular) Very bright and visible even in the strong city light pollution.

2015 Jan. 10 (1 comet) I observed C/2014 Q2 visually on Jan. 10 in Toride City, Ibaraki, Japan. C/2014 Q2 ( Lovejoy ) 4.0 mag   Dia. 24'   DC 7   (10x70 monocular)

Go to Seiichi Yoshida's Diary of Comet Observations in 2014.