Two anticyclonic oval were approaching RS which was at II:125.7 deg. (May 27, Wesley). One was the White Oval BA, which was at II:142.7 deg. (May 27, Wesley) just following RS, and prominent with light interior though little redness. Preceding BA, STBn was dark with a lot of tiny spot. The other was the dark ring in STrZ (LRS) which might derive from STrD observed last year. It has strongly orange interior with dark collar, the very aspect for Little Red Spot, and both side were connected to SEBs by dark streak. Though it had been overtaken by BA when it temporarily halted in April, accelerating again in mid-May, it was prograding toward RS with the almost same speed as BA, and reached at II:150.8 deg. on May 27 (Wesley). When writing this report, BA is already reaching RS, and LRS will also arrive at f. end of RS late June. When LRS is carried by the flow around RS, it is expected that LRS will move southward after arrival and go into the narrow channel between RS and STB. However, its motion is dominated by velocity gradient between two jetstreams on STBn and SEBs. Therefore, LRS may turn to retrograding motion, when it is forced to shift northward by some factor. Another dark ring was at II:209.3 deg. (May 20, Akutsu), but darkness and redness were less than LRS described above.

Disturbed SEBn edge preceding RS was noticeable in May. This was long-lived disturbed region in EZs (SED: South Equatorial Disturbance), repeatedly observed from 2000. The main part of this activity was a SEBn rift at I:316.3 deg. (May 7, Akutsu) accompanied by shallow bay and disturbance on SEBn edge. EZ was generally light with faint festoons, and EB was fragmentary.

Two mid-SEB outbreaks were active this month too. The first outbreak preceding RS formed disturbed region preceding II:80 deg., and its p. end was around II:0 deg. Early May, the region was much disturbed, when SED mentioned above was passing through north of this region. The activity of second outbreak was observed in a sector preceding II:250 deg., and it merged with pre-existing disturbed region following RS. So, dark SEB was seen only in a sector between II:250 deg. and 0 deg. Though both outbreaks showed spectacle aspects in high resolution images, it was vague and dim in moderate resolution images and visual observations.

SSTB was one of major belt in southern hemisphere, instead of STB which has been fading almost all round the planet. It was broad and generally double, and contained small white spots some of which are long-lived. This apparition, 9 spots were observed, increasing one. In sectors of II:60-100 deg. and II:330-0 deg., SSTB was faint between two spots, leaving both edges. In STZ, an isolated large dark spot with white core was outstanding at II:193.6 deg. (May 20, Kumamori).

NTB was strongly orange and consisted of dark straight south component and faint wavy north component. It was very broad, rivaling to NEB.

(2) Saturn

Saturn moved west sky at evening, passing stationary on May 3 and eastern quadrature on may 22. This month, we received observations listed below.

Two white spots on STBn edge were seen in images by Go on May 1 and by Tyler on May 2. The first spot was at III:332.6 deg. (Go), and it became brighter than the other one, rapidly recovering its brightness, though it had been faint since mid-March.

The second spot appeared in March was at III:299.8 deg. (Go), but it was deformed into the shape drawn out to east-north direction.

Unfortunately, neither spot was not confirmed then, because of fewer observation and poor condition.

(June 13, K. Horikawa)

(Translated on October 29)

[Fig.1] BA and LRS approaching RS

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