96/97 report 018

1996/97 Mars Observation Reports -- # 018--


- Monthly Report published in CMO #196 (25 October 1997) -

Martian Sufaces Observed from 16 September to 15 October 1997

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

This report mainly treats the observations made during the period from 16 Sept 1997 (182°Ls) to 15 Oct (199°Ls) but we are now close to an end of this apparition of Mars: The planet still remains in the evening sky observable from nearly 17:30 local time, but its apparent declination is now below 23°S and very low from our stations, and it was very difficult even this period to enjoy the benefits of better seeing though the apparent diameter was still 5.4" on 16 Sept and 5.0" on 15 Oct. The latitude of the sub-Earth point was 15°N to 06°N, and the phase angle was 36° to 32°.
The observations secured this period were as follows and we are grateful to the observers for their enduring contributions:

ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan
   9 Drawings  (19, 21 Spt; 3, 6, 12 Oct)  530, 720× 31cm speculum

MINAMI, Masatsugu  (Mn)  Fukui, Japan
  18 Drawings (24, 28, 29, 30 Spt; 6, 9, 10 Oct)  480× 20cm refractor*

MURAKAMI, Masami  (Mk)  Fujisawa, Kanagawa, Japan
   5 Drawings  (29 Spt; 1, 8, 10#, 13 Oct)  400× 20cm refr (Tama Obs)# / 315× 10cm refr

NAKAJIMA, Takashi  (Nj)  Fukui, Japan
   4 Drawings  (28 Spt;10 Oct)    480× 20cm refractor*

                                          * Fukui City Observatory

We are thankful to W MEYER for sending us the observations by H-J METTIG at Radebeul:

METTIG, Hans-Joerg  (HMt)  Dresden/Radebeul, Deutschland
  48 Drawings  (1, 2, 9 Feb; 2, 7, 8, 9, 11, 31 Mar; 2, 12, 13, 19, 20, 23 Apr; 
                1, 3, 10, 16, 19, 28, 30 May; 2, 3, 4, 6, 7, 9, 10, 14 June)
       225× 15cm Coude'  

From our lands

During the period, our observations covered the LCM from ω=188°W by ISHADOH (Id) on 19 Spt at 11:30GMT through eastwards ω=267°W by MURAKAMI (Mk) on 13 Oct at 8:20GMT.

At the latter half of September, the areas around Amazonis were seen, and on 21 Spt Id observed at ω=154°W and 164°W that Tharsis was light in the evening, and a morning area near the terminator was also misted. The southern (S) limb was light, and the north polar region (npr) was obscure but roundish.
On 24 Spt, at ω=102°W et al MINANI(Mn) watched the dark Solis L near the afternoon limb: Xanthe light, and a tail of M Acidalium was seen. The S limb light, and the npr dull whitish.
On 28 Spt, T NAKAJIMA (Nj) and Mn at Fukui saw M Acidalium more inside, but it was slightly fainter than the southern dark markings. Argyre light. Temperature was 19°C to 17°C inside the dome.
On 29 Spt, Mk observed at 8: 40GMT at ω=049°W, and Mn at ω=051°W et al. By use of a 10cm refr Mk vaguely saw M Acidalium and separately the southern dark markings. The npr was felt but not light. The afternoon limb light. By use of a 20cm refr, S Meridiani was separated. The southern markings (especially Aurorae S) looked a bit darker than M Acidalium. The npr whitish.
On 30 Spt, Mn observed at 8:30GMT (twilight) at ω=036°W when Argyre was evident light with an off-white tint. The afternoon limb light. The area from Aurorae S to Margaritifer S was quite dark. The npr was light even through a green filter.

On 1 Oct, Mk pointed out at 8:30GMT (twilight) at ω=027°W that the S limb was whitish bright, and as well on 3 Oct at 10:20GMT at ω=034 degree W and at 044°W, Id also observed the same phenomenon, and both described that it was Argyre. On the same day, seeing was so good at Naha that Id saw well the dark markings: M Acidalium was a bit fainter than M Erythraeum. Tharsis in the morning was misted. The npr looked dull smaller.
On 6 Oct, Mn observed at ω=340°W: Hellas was considerably light near the p limb (phase angle ι =33°). Syrtis Mj in the afternoon and S Sabaeus definite in the morning. At ω=350°W, Hellas was no longer visible, and the Libya cloud whitish lighter. At Fukui the sun set at about 8:20GMT and it became very hard to watch the planet after 10:00GMT, but at Naha (located more westwards) Mars was still observable and Id started from 10:10GMT at ω=002°W: S Sabaeus was seen and the morning Chryse looked misted. The npr slightly light. The p limb at the northern hemisphere light. At ω=010°W (10:40GMT), the latter limb-light part became larger.
On 9 Oct, Mn observed at ω=311°W & 321°W: Hellas largely seen but dull. Libya light near the p limb.
On 10 Oct, at Fukui Nj started from 8:30GMT at ω=299°W, and Mn at ω=303°W: Hellas looked hazy but never bright (196°Ls). Dark markings such as Syrtis Mj and M Tyrrhenum are well visible. The second observation by Nj (resp Mn) on the day was numbered Nj-281D (resp Mn-808D). Mk also started on the day (10 Oct) from 8:30GMT by use of a 20cm refr and made observations at ω=299 degree W & 309°W (at the same time as Nj): Mk clearly saw Syrtis Mj and M Tyrrhenum as well as S Sabaeus in the morning. Hellas was dull but the S limb looked lighter (maybe the south polar region because now the central latitude=08°N).
On 12 Oct, Id observed at ω=301°W & 309 degree W: Hellas was a bit light but off-white. Syrtis Mj definite. The npr to its p side looked misted. At ω=309°W, Hellas quite dull while Libya became lighter. Misted a morning area following the weak S Sabaeus. The observation was numbered Id-151D.
On 13 Oct, Mk observed at 8:20GMT at ω=267°W where M Tyrrhenum was well seen lain. The EN limb lightest in a creme tint. The observation was numbered Mk-220D.

Tohru IWASAKI (Iw) tried to observe the going-away planet handling his scope on 19, 20, 23, 28, 30 Spt; 5, 6, 8, 11, 13, 14 Oct during the present period, but each time the image was too poor to acquire any drawing. He thus regarded a drawing on 12 Sept as his last this season numbered Iw-190D.

We- Further- Received

METTIG (HMt), an active Jovian observer in Germany and a JUPOS-co- ordinator, here also obtained a lot of drawings of 1997 Mars. The observations reported covers the period from 073°Ls to 133°Ls. He makes use of OG5, BG23, VG8, RG1 filters:

1 Feb at ω=352°W, and 2 Feb at ω=357°W & 032°W: M Acidalium evident but S Meridiani not identified.
9 Feb at ω=306°W & 332°W: Syrtis Mj moved to the evening limb, and S Meridiani visible.
Days passed.
2 Mar at ω=113°W: Tharsis bright near the evening limb.
7 Mar at ω=026 degree W and 8 Mar at ω=054°W: The evening limb light. Tempe visible.
9 Mar at ω=000°W: The morning side of M Acidalium is half- toned.
11 Mar at ω=330°W: Syrtis Mj in the evening.
Days passed.
31 Mar at ω=165°W and 2 Apr at ω=161°W: Propontis I was clearly detected as well as its light neighbourhood to the north. The evening bright parts complexed.
12 Apr at ω=098°W: Nilokeras evident and Mareotis L (?) a dark patch near the centre.
19 Apr at ω=333 degree W, 011°W & 019°W: During the successive observations Syrtis Mj moved to the limb and went away, and M Acidalium appeared. Hellas was bright near the evening limb (107°Ls).
20 Apr at ω=293°W, 305°W, 326°W & 349°W: Hellas bright every observation.
23 Apr at ω=272°W, ω=283°W & ω=297°W: good shaped Syrtis Mj in every drawing. At ω=283°W, The npr consisted of a bright core and a dark line which separated a detachment.
1 May at ω=216 degree W & 224°W: Elysium and Cebrenia seen light, and Propontis I and the Aetheria dark patch were seen.
3 May at ω=188°W & 203 degree W.
10 May at ω=121°W & 134°W: The southern limb light.
16 May at ω=072°W.
19 May at ω=055°W & ω=064°W: Hyperboreus L seen (?). Argyre light.
28 May at ω=327°W: Hellas as light as the npc. 30 May at ω=304°W: Utopia was not well mapped.
2 June at ω=297°W: Syrtis Mj was faint through BG23. Hellas roundish light.
3 June at ω=286°W & ω=297°W: N Alcyonius seen (?). Syrtis Mj faint in BG23.
4 June at ω=265°W & 273°W: Syrtis Mj near the morning terminator misted.
6 June at ω=256°W & 266 degree W: No Syrtis Mj in the former while apparent in the latter (phase angle39°).
7 June at ω=252°W. 9 June at ω=212°W & 226°W: Light parts in the morning and the evening side.
10 June at ω=203°W & 216°W: Light at the p limb.
14 June at ω=167°W.

METTIG's description of the npc look stationary, that is the npc in the early days should have been drawn larger.

We hear that Isao MIYAZAKI (My) at Okinawa obtained two colour images of Mars in April which will be soon sent to us. He recently moved to a new place with a new dome equipped with his 40cm spec; the place being located 2 km east of the Kadena US Military Base. His new address is as follows:

248-12 Akamichi, Gushikawa City, Okinawa 904-2245 Japan (Phone/Fax: 81-98-974-5572)

Now that we are brought to an end of the present apparition we would like to express our gratitude to our observers for their continual contribution during this apparition to our CMO, and we hope we will be able to collaborate again in the next 1998/99 season.

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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