| Jupiter: 15/01/13 by P.Abel |
Attached is a strip drawing of the whole pl;anet cover about 35% of the total surface.
I spent some time clearing away the snow and ice from the observatory roof,
the observatory thermometer recorded a temperature of -6, very cold!
Although it was clear, and seeing was average to fair (AII-III),
low drfiting cloud did interefere with observations at times.
At around 2210UT the cloud started to to pile in and I had to hurry to finish the strip drawing off, by 2215UT cloud cover was complete.
General observations are as follows:
SPR: Vague greyish area.
SSTB: Visible at some sections of longitude, thin and greyish when present.
STZ: Bright, whitish colour
STB: Present for much of the observed longitudes. Brownish-grey in colour and contained a number of white ovals
STropZ: Bright, yellowish white region.
The STropB was present at most longitudes, though it was much more distinctive near oval BA, and the region above the GRS.
SEB: Rather a broad belt, the SEBz the darkest and most distinctive part of the belt.
The SEBz contained a number of darker and lighter sections.
EZ: Bright, EB present. Festoons slightly fewer in number tonight?
NEB: Southern part of the belt dark, with a continual (but not uniform) darker brownish section,
the northern part of the belt was somewhat lighter.
NTropZ: Birght whitish-yellow, there may have been some extensions from NEB in the NTropZ.
NTB: Northern boundary dark and irregular.
NTZ: Fairly bright, nothing of note.
NPR: Vague greyish region. Some darker sections present on the boundary with NTZ?
Filter work:
1932UT W#25A (x250): Both the main EBs are not as dark in this filter as they are in IL confirming they both have reddish-orange components of colour.
INterestingly both poles appear to be darker in this light than in IL. Dark Sects. of SEBz just as prominent in W#25A as in IL.
1938UT W#80A (x250): SPR seems to be darker in this filter. EBs about equal but the NTropZ appears to be darker.
2055UT W#80A (x250): Examined oval BA. The structure of the oval was nicely emphasized in the filter.
2058UT W#25A (x25): Oval BA virtually invisible in this light, thus BA does have a reddish component of colour.
Remark: I observed an interesting effect with oval BA. When the feature first came onto the disk,
I noticed that the colour in the spot seemed to be more distinctive when the spot was about half way between the CM and the following limb.
I repeated this when the spot transited the CM. When on the CM the spot is harder to see and more greyish in colour.
As it passed to the postion halfway between the CM and the Proc. side of the disk again it became easier to see, and the colour better defined.
A power of x250 was used through out.
[Paul G. Abel:Leicester:United Kingdom]
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