| Observer | Location | Telescope | Images/Drawings | |
|---|---|---|---|---|
| Akutsu, Tomio | (Philippines) | 35cm SCT | 8 | images |
| Asada, Hideto | (Kyoto, Japan) | 31cm Refl. | 24 | images |
| Einaga, Hideo | (Hyogo, Japan) | 30cm Refl. | 56 | images, 17 maps |
| Fukui, Hideto | (Shizuoka, Japan) | 35cm SCT. | 16 | images |
| Go, Christopher | (Philippines) | 28cm SCT | 31 | images |
| Hayashi, Toshio | (Kyoto, Japan) | 35cm SCT | 22 | images |
| Horikawa, Kuniaki | (Yokohama, Japan) | 16cm Refl. | 14 | drawings |
| Ikemura, Toshihiko | (Nagoya, Japan) | 38cm Refl. | 20 | images |
| Kanno, Seiichi | (Yamagata, Japan) | 25cm Refl. | 23 | images |
| Kazemoto, Akira | (Kyoto/Okinawa, Japan) | 31cm/50cm Refl. | 9 | images |
| Kumamori, Teruaki | (Osaka, Japan) | 20cm Refl. | 23 | images |
| Mishina, Toshiroh | (Yokohama, Japan) | 20cm Refl. | 17 | images |
| Nakai, Kenji | (Hiroshima, Japan) | 25cm MCT | 3 | images |
| Narita, Hiroshi | (Kawasaki, Japan) | 20cm Refr. | 13 | drawings |
| Neichi, Mitsuyuki | (Aomori, Japan) | 25cm Refl. | 2 | images |
| Oyamada, Hiroyuki | (Kanagawa, Japan) | 20cm Refl. | 3 | images |
| Pellier, Christophe | (France) | 25cm SCT | 5 | images |
| Salway, Mike | (Australia) | 30cm Refl. | 1 | image |
| Takimoto, Ikuo | (Kagawa, Japan) | 31cm Refl. | 54 | images |
| Wesley, Anthony | (Australia) | 33cm Refl. | 7 | images |
| Yoneyama, Seiichi | (Yokohama, Japan) | 20cm Refl. | 21 | images |
| Yunoki, Kenkichi | (Osaka, Japan) | 26cm Refl. | 89 | images |
This month, rift activity in NEB attracted attention. NEB generally seemed to be quiet in this apparition, the belt became narrow because its northern edge faded away, and interior of it was uniformly dark, though rift activity was observed in June. This activity began from tiny white spot which was located immediate north of NEBs, and typical oblique rifted region oriented from preceding-south to following-north was formed. The white spot has been observed since late July, and was rapidly prograding with a drift rate of -4.4 deg./day. When it reached at II:37.8 deg. (Go) on Aug. 5, the rift began developing to east-west direction. The entire rifted region prograded with much faster speed than System II, and the length of the region, which was only 15 deg. on Aug. 5, extended rapidly to 35 deg. on Aug. 15, and to about 50 deg. on Aug. 24, because southern part was moving more faster (close to System I) while northern part moved slowly, according to velocity gradient in NEB. The initial white spot was clearly seen in the rifted region like a core at first, then several white spots appeared as the region developed longitudinally. At the end of August, the p. end of this region was at II:240 deg., and the region lengthened to about 70 deg. It became disturbed light band rivaling SEB with a lot of brilliant spots.
Moreover, another rifted region emerged in NEB late August. It transformed into a rift after Aug. 23 from a tiny white spot in NEBs which was at II:173.2 deg. on Aug. 15 (Yunoki). Wesley's image on Aug. 28 showed that the original spot at II:101.4 deg. was trailing a white strip. It will prograde rapidly and develop longitudinally as well as above regions.
RS fell into typical RS Hollow by dark arch surrounding south of it, after it encountered LRS. Dark arch became still darker, and its sharp interior outline was RS itself. Though inside of Hollow was slightly reddish in general and dark core was still seen, it was rather light since it was surrounded by dark materials. RS Hollow was at II:128.2 deg. (Aug. 18, Einaga), and was slowly retrograding. When RS turns into Hollow, its rotation period tends to become shorter. But such acceleration was not observed so far. The p. end of dark arch formed a short streak in STrZ for some time, and it began suddenly extending since Aug. 20. On Aug. 28, the p. end of it reached II:94.7 deg. (Wesley), forming a prominent dark streak of 25 deg. in length. It should be observed carefully next month.
On the other hand, previously developed dark streak along SEBs, described in last report, was extending slowly, and its p. end was at about II:280 deg. It indicates that it has not been caught by STBn jetstream, yet. Preceding part about 40 deg. long was prominent, largely separating from SEBs, but in the following part, it was difficult to separate from SEBs, because it was closer to SEBs edge, and in some places, it broke to shorter fragments like chain of dark spots. Though the streak seemed to continue to preceding RS, it did not connect with the dark streak mentioned above.
BA was seen as light reddish oval at II:99.7 deg. on Aug. 20 (Takimoto). STBn was dark like a dark streak in 50 deg. preceding BA, and some rapidly prograding jetstream spots were formed from p. end. When these spots overtook a slower spot on STB at about II:15 deg. in succession, the apparent arrangement among these spots changed rapidly. Large dark oval in STZ was at II:143.8 deg. (Aug. 27, Kazemoto), reaching near f. end of RS. It was still very prominent with bright core in high resolution images. There were six prominent barges on NEBs edge all round the planet. Also three remarkable bay of the belt were observed, probably due to white spots which had assimilated into NTrZ. The one at II:297.4 deg. (Aug. 7, Yoneyama) was long-lived WSZ, which was faintly seen in NTrZ. Though NNTB had been indistinct all round the planet, two darker belt segment was observed at II:350-60 deg. and 180-230 deg. this month.
(September 14, K. Horikawa)
(Translated on May 27)
[Fig.1] RS became Hollow |
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| 2008/08/18 10:23UT |
| I:62.7 II:109.9 H. Einaga (Hyogo, 30cm) |
[Fig.2] Development of NEB rifted region |
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| These maps were created in special longitude system which prograded at -4.5 deg./day relative to System II. |
| System II longitudes indicated in parentheses were applied to white line in map. |