96/97 report 019

1996/97 Mars Observation Reports -- # 019--


- Monthly Report published in CMO #197 (25 November 1997) -

Martian Sufaces Observed from 16 October to 15 November 1997

- - - by Masatsugu MINAMI, Director of the OAA Mars Section ---

The planet Mars is going away. The apparent diameter was 05.0" on 16 Oct, but at that time the apparent declination was down to 23°S, and then further the altitude went down. On 16 Oct the Martian season read 199°Ls, the central latitude was 06°N and the phase angle was 32°.

We received the observations since 16 Oct from three observers as listed below: The final observation of the OAA was made by MURAKAMI (Mk) on 9 Nov when the apparend diameter was 04.8", the central latitude was 02°S, and the phase angle was 29°: The season was 214°Ls. Mk observed the planet 263 times this apparition out of which he contributed a total of 226 drawings to the CMO. ISHADOH (Id) also pursued the planet up until 3 Nov just when the central latitude went from 00°N to 00°S. His final observation was numbered Id-154D. NAKAJIMA (Nj) at Fukui also took a drawing on 24 Oct, and this was his last observation this season numbered Nj-282D.

We received the most recent observations from the following observers:

 ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan
  3 Drawings  (17, 20 Oct; 3 Nov)  530x 31cm speculum

 MURAKAMI, Masami (Mk) Fujisawa, Kanagawa, Japan
  6 Drawings  (18, 29 Oct; 3, 8, 9 Nov)  315x 10cm Nikon ED refractor

 NAKAJIMA, Takashi  (Nj)  Fukui, Japan
 1 Drawing  (24 Oct)    270x 20cm ED refractor*

                                          * Fukui City Observatory

We are thankful to the following observers for sending us their observations made earlier:

 Nicolas BIVER (NBv)  Versailles, France
   8 Colour Drawings  (8 Nov 1996; 30 Jan, 7 Feb, 17, 18# Mar; 20, 30 Apr; 3 June) 
             510x 26cm speculum / 520x 60cm Cass (at Meudon)#

 David J LEHMAN  (DLm)   CA, USA
   9 Drawings  (22, 23 Feb; 5, 13, 14 Mar; 22 Apr; 1, 5, 10 May)  280, 290x 25cm speculum

 Randy TATUM  (RTt)  VA, USA
   1 Drawing  (18 March)    ?x  25cm speculum

From our lands

On 17 Oct, ISHADOH (Id) observed at ω=255°W: M Cimmerium was dark while Syrtis Mj was misted unseen. The southern limb was a bit light, but the central latitude was still 07°N, and furthermore Hellas was present so that the south polar cap (spc) was not separated. The north polar region (npr) looked slightly light.
MURAKAMI (Mk) then observed on 18 Oct at ω= 218°W when the central latitude 05°N and the season was 201°Ls, and found that the southern limb was light though not large. This must have been the south polar cap (spc) because Hellas was then much before dawn. The dark areas in the southern hemisphere were visible.
On 20 Oct, Id observed at ω =228°W and felt that the southern limb was slightly light. The eastern limb to the npr was whitish light.
On 24 Oct, NAKAJIMA (Nj) made his final observation this season at ω=172°W: Seeing was poor but the southern limb looked slightly light.
On 29 Oct, Mk took a drawing at ω=106°W, but the southern limb was obscure. The eastern limb of the northern hemisphere to the npr was whitish light.
On 3 Nov, the Martian equator came to the sub-Earth point, and the henceforward the southern hemisphere became totally observable: Firstly at 7:50GMT (4:50pm local time), Mk observed the planet at ω=054°W to find the southern-limb region to be light (not so large however). M Erythraeum and M Acidalium were vaguely seen. The area around the npr remained the same as before. Mk then observed at ω= 064°W: The southern limb similarly light, and the dark markings were caught. The whitish aspect of the npr to the preceding limb was the same. Thirdly Id watched the surface at ω=086°W, but seeing was so poor that the southern limb looked dull.
On 8 Nov, when already De=02°S, Mk observed at ω=003°W and detected that the southern-limb area was light. Since the season was 213°Ls, we consider that the area corresponded to the spc. A shadowy spot near S Meridiani. The temperature was recorded 14°C at Fujisawa.
Finally on 9 Nov, Mk observed at ω=356°W, De=02°S, and saw also that the southern limb light. Chryse looked misted in the morning.
It should be noted that MURAKAMI's observations were made in the very twilight and hence the image each time was under a low contrast to the extent that he could not see the brightness of the spc and rather the light region looked smaller, but the very thing was no other than the npc because the season was deep to 210°Ls. The spc was expected to be seen since mid- October, but the south pole was away yet and the area of Hellas was facing toward us and hence the spc was not separated. The next apparition will be more appropriate to see the appearance of the spc.

As cited in the LtE, N BIVER (NBv) detected the spc at Hawaii in mid- November (Honolulu is situated slightly more southward than the southern end of Taiwan in latitude).

We- Further- Received

BIVER (NBv) sent us eight beautiful drawings in colour. These were obtained in France though he is now at Hawaii (see LtE). NBv is one of well-known observers of Mars in France. Once cited was a drawing of his in a previous apparition in CMO #140 p1331 which was made on 15 Feb 1993.

The first drawing we received this time was dated 8 Nov 1996 when the app diam δ=05.7": Propontis I was clearly detected when ω=175°W while it looks to have already passed the CM.
On 30 Jan 1997 he made at ω=096°W where Solis L and M Acidalium were near the evening terminator. The southern limb looked yellowish, and Tharsis was slightly whitish misted. The season was at 072°Ls.
On 9 Feb ω=006°W, Oxia P was quite evident, and Deuteronilus consisted of several spots.
On 17 Mar, he observed at ω=294°W where Syrtis Mj was near the CM, and S Meridiani was near the morning limb. Hellas was well whitish near the noon, and Elysium Mons was a white spot near the evening terminator.
Olympia is not evidently depicted On 18 Mar (at opposition) use was made of a 60cm Telescope at Meudon at ω=018°W: Oxia P looked divided to two, and M Acidalium was made of three patches, the west most being darkest. Hyperboreus L was visible. The season was at 092°Ls and the app diam=14.2".
On 20 Apr at ω=352°W, Chryse was slightly yellowish misted in the morning, and Hellas was white on the evening limb. Libya dull yellowish preceding Syrtis Mj. Hyperboreus L was seen.
On 30 Apr at ω= 258°W, NBv seemed to see Olympia outside the dark fringe of the npc. Elysium was slightly yellowish. Hellas was whitish at the morning limb. Syrtis Mj was not weak nor light-blue.
On 3 June at ω=292°W, the apparent disk diameter was already 08.9", and the description of Utopia was deformed, while Hellas was very whitish bright, and Olympia looked vivid.

LEHMAN (DLm)'s first report was cited in #180 p2021, and the present one goes as follows:
On 22 Feb (081°Ls, apparent diameter δ=12.7") he observed at about ω=270°W where Syrtis Mj was seen, and Hellas was bright through blue (#38A). Intensity estimates by use of #23A: The morning Hellas was 1.5, while Ausonia Australis 1 (the npc 0).
On 23 Feb at about ω= 325°W, he observed S Sabaeus near the CM, with intensity 5, while the evening Syrtis Mj 3. Aeria light (2.8) and Libya was 2 at the evening terminator.
On 5 Mar he seemed to watch ω=164°W ~ 171°W but the disk shows some dark marking near the evening side as if M Acidalium was present.
On 13 Mar at ω=100°W, DLm caught a tail of M Acidalium with intensity 5. The light markings were Argyre with 2 and Xanthe with 1, both of which were also seen through #38A. Alba was also light with 3 through #23A.
On 14 Mar at about ω=100°W, he detected a series of dark patches along the evening terminator. Alba was slightly light with 2.5 near the CM. On 22 Apr at around ω=015°W, M Acidalium was dark in the afternoon side with intensity 7, and the dark fringe of the npc was 6.5. Chryse was light in the morning (2.5).
On 1 May at around ω=005°W, the southern limb light with intensity 2. Syrtis Mj was 7.5.
On 5 May at around ω=320°W he observed Hellas to be very bright (intensity 0) through #23A as well as through #80A. The season was 114°Ls. Two light spots pinching Syrtis Mj.
Finally on 10 May at 95°W, he estimated Hellas 0.5. Syrtis Mj 7.5, and Utopia 5. The disk diameter then was 10.7".

TATUM (RTt)'s observation was made on the opposition day on 18 Mar (092°Ls) at ω=021°W, De=23°N and the app diam δ=14.2".
The description is rough but he has a keen eye to realistically describe the protrusion of S Callirrhoes from the M Acidalium. Tempe roundish light. S Meridiani was near the evening limb as a dark spot. He seems to have seen Hyperboreus L around the npc.

Real-time report will be impossible any longer, but this column shall appear for the present continually if any additional information on Mars this 1996/ 97 apparition is received.
Reports will be acknowledged if air-mailed to M MINAMI at Mikuni
(ask the mail-address through vzv03210@niftyserve.or.jp ) .

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