Monthly Report of the OAA Jupiter-Saturn Section, November, 2005

Director: K. Horikawa, Secretary: Y. Iga

(1) Jupiter

Jupiter had passed solar conjunction on Oct. 22, and new apparition for Jupiter observation has come. Though observation conditions were quite poor and observers' major interest was Mars which just passed the opposition, we received observations from eager observers listed below.

ObserverLocationTelescopeImages/Drawings
Einaga, Hideo(Hyogo, Japan)25cm Refl.36images, 2 maps
Fukui, Hideto(Shizuoka, Japan)25cm Refl.25images
Horikawa, Kuniaki(Yokohama, Japan)16cm Refl.3drawings
Kazemoto, Akira(Kyoto, Japan)31cm Refl. 3images
Miyazaki, Isao(Okinawa, Japan)40cm Refl.1image
Yoneyama, Seiichi(Yokohama, Japan)20cm Refl.1image

The first observation of new 2006 Apparition was made by Fukui on Nov. 4. On the next day, Nov. 5, Miyazaki took an image, followed by Horikawa on Nov. 8, Einaga on Nov. 16, and Kazemoto on Nov. 17. Only 13 days had passed since solar conjunction, when Fukui made first observation. It was still earlier than 14 days in the last apparition made by Miyazaki. Because Fukui's last image in previous apparition was on Oct.1 (21 days before solar conjunction), the gap in his observation was only 34 days.

Although it was worried that sudden change might took place in northern hemisphere during solar conjunction, every image shows uniformly bright zone north of NEB without any irregular dark markings. Therefore, it seems that North Temperate Current-C (NTBs jetstream outbreak) had not started yet. NTB was absent at all longitude, and only wide bright zone which consisted of NTrZ and NTZ can be seen. NNTB was also partly seen at southern edge of NPR, and thare was no prominent feature north of NEB.

NEB was still broad. It was very reddish, and it had irregular shadings inside in many images. Einaga's images on Nov. 30 showed three small white spots in NEBn edge following RS. These had been formed in last apparition, and as observed in former example, they will become more conspicuous. On NEBs edge, bluish dark plateaus and festoons could be seen. EZ was not very light, and EB was fragmentary.

RS was reddish, but somewhat faint with diffuse outline. Its aspect was almost the same as that in late stage of previous apparition. It retrograded a little to about II:107 deg. Following RS, SEB was active with irregular light band which extended to about II:190 deg. SEBZ active region (post-GRS disturbance) temporarily became active in Apr. 2005, but it declined after that, showing weak activity of white cloud within the range of only 20-30 deg. following RS. Therefore, it is conjectured that new activity had started during solar conjunction. Other SEB appeared as almost uniformly dark broad belt. The next remarkable belt in southern hemisphere was SSTB, which was broad and prominent as in last apparition, but with much irregularities in darkness. BA is estimated at about II:230 deg. in mid-November, but it is not found at present. Preceding and following RS, irregular dusky band, probably STBn, could be seen.

(2) Saturn

Saturn came to appear in the eastern sky before midnight, having passed western quadrature on Nov. 3 and stationary on Nov. 22. Though we had few night in good seeing because of winter monsoon which began to blow, it seemed that most observers tried to image Saturn following Mars. This month, we received observations listed below.

ObserverLocationTelescopeImages/Drawings
Akutsu, Hiroaki(Hokkaido, Japan)28cm Refl.12images
Einaga, Hideo(Hyogo, Japan)25cm Refl.18images
Fukui, Hideto(Shizuoka, Japan)25cm Refl.1image
Ikemura, Toshihiko(Nagoya, Japan)31cm Refl.5images
Kazemoto, Akira(Kyoto, Japan)31cm Refl.15images
Morita, Mitsuji(Shiga, Japan) 20cm Refl.1image
Nakai, Kenji(Hiroshima, Japan)25cm MCT2images
Nakanishi, Hidekazu(Aichi, Japan)30cm Refl.2images
Takimoto, Ikuo(Kagawa, Japan)31cm Refl.7images
Tatum, Randy(USA)25cm Refl.1image
Vandebergh, Ralf(Netherlands)25cm Refl.2images
Yoneyama, Seiichi(Yokohama, Japan)20cm Refl.3images
Yunoki, Kenkichi(Osaka, Japan)20cm Refl.7images

It is a follow-up on white spot and dark spot-like marking which was seen on Vandebergh's image taken last month. First, white spot in EZ around I:80 deg. was not able to be found in any images this month. On the other hand, Ikemura's image on Nov. 4 showed a faint shading which was suspected to be the STB dark spot around III:50 deg. Though Vandebergh processed this image to emphasis the spot, it was doubtful whether it was a true feature, partly because it was close to limb. Also, Kazemoto observed the same region on Nov. 7, but no feature was seen.

No other markings like white spots were observed this month.

(December 9, K. Horikawa)


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