CMO Monthly Report
published in CMO #237 (25 November 2000)
Martian Surfaces until 15 November 2000 (~076°Ls)
We resume this column to review the observations submitted to the CMO every month. The dead line of observations is the 15th , and so this column treats the one-month period from the 16th day through the next 15th for the time being.
The apparent diameter was 4.0 seconds of arc on 27 October. The season was 068°Ls, the central latitude was 26°N and the phase angle was 22°. The season corresponded to the one we met at the beginning of March 1995 (Mars at opposition on 12 Feb 1995) or at the end of January 1997 (opposition on 17 Mar 1997). On 15 November, the apparent diameter increased to 4.3" arc, the season proceeded to 076°Ls, the central latitude was down to 25°N and the phase angle was up to 25°. The tilt will come further down to the south until April 2001, and the phase will increase toward to the end of February.
A list of the observations we thus received this period is as follows:
MINAMI, Masatsugu (Mn) Fukui, Japan
11 Drawings (27 October; 4, 5, 13, 14 November 2000) 340,400x 20cm refractor*
MORITA, Yukio (Mo) Hatsuka-ichi, Hiroshima Japan
6 Sets of CCD Images (30 October; 2 ~ 5, 7 November 2000)
f/50 25cm spec equipped with an ST-5C
NAKAJIMA, Takashi (Nj) Fukui, Japan
3 Drawings (27 October; 13, 14 November 2000) 400x 20cm refractor*
PARKER, Donald C (DPk) Miami, FL, USA
1 Drawing (11 November 2000) 440, 510x 41cm f/6 spec
1 CCD Image (11 November 2000) f/55 41cm spec equipped with a Lynxx PC
* Fukui City Observatory
The first Martian images obtained by Nj and Mn on 27 Oct were not sufficient because of a presence of thin cloud, but the north-polar cap (npc) was seen bright and definite at around LCM=130°W, though Nj thought of its size as being slightly smaller than the one he expected for De=26°N. The south polar limb was unexpectedly light.
On 4 and 5 Nov (072°Ls), the present writer (Mn) watched the surface from LCM=033°W to LCM=062°W, and detected M Acidalium as well as the roundish npc: The npc looked as normal and appeared to be surrounded by a broad dark fringe. The southern hemisphere showed also a shadowy region, but not identified. Chryse was slightly light in the evening, and the morning Tharsis looked whitish near the limb. The observation was possible until just after 21:00 GMT.
MORITA (Mo) secured the RGB images on 3 Nov at LCM=073°W and on 4 Nov (072°Ls) at LCM=060°W, the latter image in R shows M Acidalium definitely on the afternoon side (exposed 0.4 secs) though the npc looks weak. There seems to exist a light core in Chryse.
On 7 Nov, he proceeded to the image at LCM=029°W.
On 11 Nov (075°Ls), Don PARKER (Dpk) produced an excellent CCD image and a drawing. He first observed Mars by the naked eyes at 10:05GMT ~ 10:25GMT and obtained a nice sketch at LCM about 195°W where the bright npc was evident as well as the dark Propontis I. Elysium was near the CM, but not so evident as the dark band of Cerberus-Phlegra. A morning mist was seen at an equatorial morning limb, and M Cimmerium was dark in the morning. The planet was then at an altitude of 23°. Later higher up at 35°, Dpk shot Mars by his cooled CCD camera at 10:54 GMT, and proved the evident npc with a surrounding dark fringe at LCM=203°W. There is seen also a faint marking in the southern hemisphere. The raw images were obtained by the exposure of 0.7 secs through an RG610 filter, and two of them were composed to a final image. He described that at Miami, behind a cold front, the temperature was 21°C, much warmer than here at Fukui (here it is under ten degrees Centigrade these days). Florida is more ahead by 10 hours (or 150°W) than in Japan.
On 13 and 14 Nov (076°Ls) we observed the surfaces LCM=310°W ~ LCM=334°W at Fukui. The npc was definite and roundish bright with the dark band extending to the direction of M Acidalium. Syrtis Mj was faintly seen on the upper side, and Hellas seemed seen a bit near the terminator. The west-southern limb was slightly light following Noachis.