96/97 report 016

1996/97 Mars Observation Reports -- #016--

OAA MARS SECTION - Monthly Report published in CMO No 194 (25 August 1997)

Martian Sufaces Observed from 16 July to 15 August 1997

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

This is the 16th OAA report of this apparition, and mainly treats the observations made during the period from 16 July through 15 August 1997. The Mars observation has been more difficult, but if we catch the planet by a finder around the time of Sundown, we can obtain still a better image. The difficulty is not because of the apparent diameter, but because the planet is already far east of Spica, Vir, and declined very southward (-12° in mid-Aug). The diameter itself was 6.9" on 16 July and 6.0" on 15 August. The season proceeded from 149° Ls to 164° Ls during the period. The central latitude was 25° N down to 22° N. The phase angle also decreased from 40° to 39° .
We received with thanks the following observations this time:

      HIKI, Toshiaki  (Hk)   Minowa, Nagano, Japan
            3 Drawings  (26, 27 Jly; 11 Aug)  340×  16cm speculum 

      ISHADOH, Hiroshi  (Id)   Naha, Okinawa, Japan
            3 Drawings  (18, 20 July; 14 Aug)  530×  31cm speculum

      IWASAKI, Tohru  (Iw)   Kita-Kyushu, Japan
           12 Drawings  (18, 20, 21, 22, 24, 25, 30 Jly)  400×  21cm speculum

      MINAMI, Masatsugu  (Mn)  Fukui, Japan
           34 Drawings (18, 19, 22, 23 Jly; 1, 2, 3, 8, 11, 15 Aug)
           480,600×  20cm refractor*

      MURAKAMI, Masami  (Mk)   Fujisawa, Kanagawa, Japan
            8 Drawings  (18+, 19+, 20 Jly; 3$ Aug)
            315×  10cm refr+/370×  15cm spec
            400×  20cm refr$  (Tama AstroObservatory)

      NAKAJIMA, Takashi  (Nj)  Fukui, Japan
           17 Drawings  (18, 19, 20 Jly; 2, 11, 15 Aug)
           480,600×  20cm refractor*

      SCHMUDE, Richard W, Jr  (RSc)  GA, USA
            3 Drawings  (3, 6 Aug)     380×  51cm speculum

      WARELL, Johan  (JWr)  Uppsala, Sweden
            2 Drawings  (28 Jly; 4 Aug)
            380×  38cm WASHdob at Tenerife, Spain (alt 2080m)
                                      * Fukui City Observatory

We also acknowledge receipt of the reports from the following observers (Deutsch observations were kindly sent to us from Wolfgang MEYER, WFS):

      BUGGENTHIEN, Ruediger (RBg)  Luebeck, Deutschland
           16 Drawings  (14,15 Dec; 29 Jan; 1,2,27 Feb; 4,5,6,9,17 Mar;
                            6,7, 19 Apr; 10,18 Jne)  
                           160,220,240,280×  18cm ED refractor 

      ISHIBASHI, Tsutomu (Is)  Sagamihara, Kanagawa, Japan
            7 B&W photos  (23 Feb; 4 Mar; 1, 10, 27 Apr; 28, 30 May) 
                               31cm speculum   HIE, 400Prest, TP2415

      KISMANN, Elmar  (EKm)   Berlin, Deutschland
            1 Drawing  (5 Mar)       250×  15cm refractor %

      LINKE, Christian W  (CLk)   Berlin, Deutschland
            3 Drawings  (5, 7, 8 Mar)       250×  15cm refractor %

      VOELKER, Peter (PVk)   Berlin, Deutschland
            1 Drawing  (1 Feb)       185×  11cm refractor
                               % Wilhelm Foerster Sternwarte, Berlin

From Japan
During this period we observed the surface where M Acidalium prevailed first, and then S Sabaeus, Syrtis Mj, and finally up until the surface around ω =160° W.

On 18 July (150° Ls):, we started at Fukui from 10:00GMT (19:00JST: twilight): The observations by MINAMI (Mn) at ω =060° W and NAKAJIMA (Nj) at ω =065° W recognised the dark Aurorae S but didn't do Eos which was said dust clouded before. Argyre light at the southern (s) limb. MURAKAMI (Mk) observed at ω =075° W where he noticed Chryse-Xanthe light in a creamy tint at the afternoon side, and a dull morning mist. IWASAKI (Iw) then observed at ω =082° W where M Acidalium was still dark near the preceding (p) limb. At Fukui we observed up to ω =089° W(Mn) and ω = 094° W. ISHADOH (Id) observed at ω =102° W where the morning terminator misty from the s limb. The p limb also light preceding the dark and already slim M Acidalium. The north polar cap (npc) was described as follows: small but whitish bright by Nj, bluish white by Mk and shiny by Iw, and small roundish light by Id.

On 19 July: Mk started from ω =048° W (at 09:50GMT) where M Acidalium was dark near the CM and its preceding side was light in a creamy colour. Mk observed then at ω =058° W & 067° W, where Tempe was roundish light and the p limb looked light showing a cream tint. The npr blue-whitish. At Fukui we observed from ω =055° W to ω =089° W: At ω =055° W, the p limb was light from Noachis to Thymiamata. Eos was not light. Tharsis morning misted.

On 20 July: Mk observed at ω =048° W & 058° W, where Chryse-Xanthe is not particularly light. Light patches at the s limb and a morning terminator. The p limb light. Tempe roundish in the latter observation. Nj observed at ω =060° W, and, though annoyed by a thin haze, observed M Acidalium and the shiny npc. Argyre light. Iw made a drawing at ω =063° W, the drawing being numbered 169 for this apparition, but corresponded to the 2001th drawing ever since 1984 when he started as a Mars observer. Still made at ω =072° W where M Acidalium was still quite dark near the p limb. Id observed at ω =068° W where Nilokeras to Ganges faintly seen while Eos was not identified though the p limb light. The morning Tharsis misty. The npc obscure.

On 21 July: Iw observed at ω =053° W & ω =063° W when it was hazy and the npc didn't shine. Argyre was recognised, and Eos might be faded. A part of Tempe looked light in the morning.

On 22 July: Mn observed from ω =021° W to ω =060° W: At ω =021° W, S Meridiani was quite inside the disk. The morning Chryse was misty and Tempe dull. Tharsis was also dull while Argyre was very apparent. The p limb at the northern hemisphere was light (phase angle ι =40° ). Hyperboreus L was obscure (hazed?). At ω =031° W, the npc was definite while Hyperboreus L remained obscure. Tempe became whiter. In a Green light, Argyre, the p limb and the npc bright. At ω =041° W, Argyre apparent through O56 filter. Aurorae S was quite dark and Eos looked faded. In Int the npc was bluish white and roundish. Argyre also white. Through a Green light a morning mist was visible. Iw observed at ω =043° W, where Argyre was whitish, a morning mist over Tempe, and the p limb light, and at ω =053° W, the p limb very light and he recognised that Argyre moved by the rotation.

On 23 July: It was hazy at Fukui with poor seeing, just the dark M Acidalium and the light Argyre.

On 24 July: Iw observed at ω =024° W & ω =033° W: The npc was small shiny, S Margaritifer weak. A morning mist following M Acidalium at ω = 024° W. Didn't notice the p-limb light.

On 25 July: Iw observed at ω =014° W where S Sabaeus was definite. At the s limb, a white patch, related with Argyre, was evident. A morning mist following M Acidalium. Margaritifer S faded.

On 29 July: HIKI (Hk) observed at ω =330° W, where Hellas light and Syrtis Mj dark while he didn't recognise S Sabaeus. Noachis rather shadowy. M Acidalium coming.

On 30 July: Hk observed at ω =318° W: Hellas not so light, The western part of S Sabaeus was checked. Iw observed at ω =325° W: Syrtis Mj was still very dark. A bit of Hellas. Noachis dull. S Sabaeus was weak at the eastern part. a white light cloud at the p limb. At ω =335° W, S Meridiani was dark from the morning.

On 1 August (157° Ls): Mn started from ω =286° W, where Syrtis Mj was near the CM while Hellas was not particularly bright. At ω =296° W, the p limb light and in G a morning mist was visible on the other hand. At ω = 306° W, M Serpentis seen dark. The npr was obscure while looked white at ω =316° W. S Sabaeus coming.

On 2 August: At Fukui Nj started from ω =281° W, and Mn from ω = 286° W: Hellas was not so light, and the npc looked whiter. Hellas was nearly at 9:00am local Martian time. Nj noticed the Aetheria dark patch. Up to ω =306° W the day. Hellas remained dull. The npc seen sharply. the p limb slim light.

On 3 August: Mn observed at ω =262° W(09:50GMT) where Ausonia Australis was whitish light. Syrtis Mj was already dark without following mist (phase angle ι =40° ). M Cimmerium was dark near the p limb and its north limb- light. The npc was white. At ω =272° W, Hellas just seen. (City-fireworks downwards at Fukui City.) Mk who observed by a 20cm refr at Kawasaki observed at ω =267° W & 277° W: Syrtis Mj was quite visible from the outset, its southern part darker. A morning mist over Aeria following Syrtis Mj. Ausonia Australis light. Elysium was however not detected. Utopia definite.

On 8 August: Mn watched at ω =213° W where Elysium was not seen.

On 11 August: At Fukui Mn started from ω =186° W, and Nj from ω = 191° W: Both didn't see any light Elysium. Difficult to see the shape of Propontis I. The p-limb light has a lighter core. Up to ω =206° W. Hk observed at ω =194° W, where a dark area including Propondices was seen. The npr was vaguely light. Temperature was 28° C at Minowa (Valley at a mountain side)

On 14 August: Id observed at ω =187° W, where the northern p limb was particularly light. The morning area in the southern part looked misty. The npc obscure.

On 15 August: At Fukui Nj started from ω =157° W, and Mn from ω = 162° W. The northern p limb was bright, maybe the area from Tharsis to Alba.

Overseas Observations

SCHMUDE (RSc) observed on 3 Aug at ω =135° W & ω =145° W: A light patch at the p limb, not so light as the npc. The dark marking indefinite. On 6 Aug at ω =120° W: the light patch at the p limb prolonged into the inside, the lightest. Another isolated light spot near the CM.

WARELL (JWr) observed at Tenerife on 27 Jly (155° Ls) and on 4 Aug: The former was made at ω =134° W where the npc was blue-whitish and the southern limb is covered by a large creamy matter. Two light patches at the p limb. The latter shows M Acidalium, but the most prominent is the southern -limb light area, off-white. The npc was not well defined. Temperature was 18° C, while the pressure only 790hPa.

We- Further- Received

BUGGENTHIEN (RBg) made the drawings by use of a diagonal and so it is difficult for us to judge his observations.
On 15 Jan at ω =199° W, he isolated Propontis I (app diam δ=9.1"): Elysium seems visible though he noted Elysium and Cerberus et al were kaum sichtbar.
On 2 Feb at ω =025° W RBg drew Oxia P as a tiny stain.
He also drew on 27 Feb (084° Ls) at ω =154° W Nix Olympica which was at the afternoon side as a dark spot instead of a light spot.
On 4 Mar at ω =097° W, he observed a detachment (Eisinsel) inside the npc made by a fissure which he identified as Rima Tenuis. A light area at Tempe. Solis L roundish but no Tithonius L.
On 6 Mar at ω =028° W (and et al) a dark broad band running from Nilokeras westward was seen.
Hellas was only observed on 17 Mar (092° Ls) at ω =319° W where Hellas was only light in B625.
On 10 Jne at ω =212° W, Cerberus-Styx looked very dark.

ISHIBASHI (Is)' s photos are as follows:
23 Feb at ω =017° W, the southern Thymiamata is light through B390 (Blue filter, see #84 p706), but interestingly the preceding area of M Acidalium is quite shadowy. The npc is visible in B390 (though rather obscure in Red and IR).
4 Mar (086° Ls) at ω =336° W, S Sabaeus and S Meridiani definite in R; the northern part of the evening Syrtis Mj is quite misted through B390. Hellas a bit seen in B. Notable is that Cydonia and its surroundings are shadowy through B390, not distinguishable from the morning M Acidalium. The morning limb is however misty light.
1 Apr at ω =024° W, as on 23 Feb, the preceding area to M Acidalium is shadowy in B390. The morning Tempe is slightly faded. Note however that the aspect is different to that before the opposition.
10 Apr (102° Ls) at ω =310° W, Hellas is naturally apparent through B390. Syrtis Mj is not visible in B but the EBC is delicate.
27 Apr (110° Ls) at ω =163° W, the Tharsis cloud is very conspicuous in B390. On 28 May a set is taken at ω =124° W. 30 May at ω =194° W, Elysium is light in addition to Tharsis in B390. Elysium is apparent in a TP photo and Propontis I is isolated and Cerberus-Styx is dark (App diam δ=9.2").
Is's work is composed of 7 sets but a total 57 photos are used.

KISMANN (EKm)'s observation was made on 5 Mar at ω =045° W and LINKE (CLk)'s ones on 5 Mar at ω =043° W, and on 7/8 Mar at ω =045° W/ 054° W: all show M Acidalium near the CM with the npc.

VOLKER (PVk) made a drawing on 1 Feb at ω =013° W: M Acidalium was in the morning. The npc looks too large.

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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