20

th Report:

The CMO/OAA Observations made during a fortnight period

 from

1 December 2003 (308°Ls)

to

15 December 2003 (317°Ls)

 

An OAA Mars Section article to be published in CMO #285 (25 December 2003 issue)

 Masatsugu MINAMI, Director of the OAA Mars Section

Japanese version here

T

his time we review the CMO Mars observations made during the period from 1 December (λ=308°Ls) to 15 December (λ=317°Ls): This period was important because it meant still the Martian season for dust storms as stressed by R McKim (RMk) on 18 November (#283 LtE). However since the apparent diameter δ decreased from 11.1" to 9.7", routine observers much decreased. In Japan the typical winter climate prevailed: but fortunately those who faced to the Pacific Ocean like Tomio AKUTSU (Ak) and Teruaki KUMAMORI (Km) were quite active, while those living at the rear side (eg at Fukui) had less opportunity to watch. During the period, the central latitude φ was 26°S, and the phase angle ι =42°. The expected dust storm was clearly detected by Don PARKER (DPk) on 13 December (λ=315°Ls) when δ=9.9". 

 

T

he observers who contributed this time are as follows: Elisabeth SIEGEL (ESg) in Denmark enjoyed many more evenings than at Fukui though the temperature at her place sometimes went down below the freezing point (while at Fukui the temperature was around 5°C).

 

AKUTSU, Tomio (Ak)  Karasuyama, Tochigi, Japan

            7 Sets of CCD Images (+19 IR image)

(3, 8, 10, 13, ~15 December 2003)

                                f/33×32cm spec with a Bitran BJ-41L

    

BENAVIDES, Rafael (RBn)  Córdova, España

            2 CCD Images (11 December 2003)  24cm SCT with a ToUcam

    

BIVER, Nicolas (NBv)  Versailles, France

            2 Colour Drawings (9, 15 December 2003) 　510×26cm spec

    

CAPARRÓS, Angel (ACp)  Málaga, España

            1 CCD Image (12 December 2003) 

  F/4.8 25cm spec with a ToUcam

    

COLVILLE, Brian (BCl) 　Ontario, Canada

            1 Set of CCD images (14 December 2003) 

 f/44×25cm SCT with a ToUcam Pro

    

COOPER, Jamie (JCp)  Northampton, UK

            1 CCD Image (15 December 2003)

                         f/30×18cm Intes-Micro Mak-N with ToUcam

     

GRAFTON, Edward A (EGf)  Houston, TX, USA

            1 Set of CCD Images (15 December 2003)

 f/39×35cm SCT with an ST-5C

    

IWASAKI, Tohru (Iw)   KitaKyushu, Fukuoka, Japan

　　　  　  5 Drawings (2, 4 December 2003)   400×21cm speculum

    

KARRER, Michael (MKr)　 St Radegund, Österreich

            1 CCD Image (9 December 2003)

                       f/35×18cm Meade Refraktor with a ToUcam

     

KUMAMORI, Teruaki (Km)   Sakai, Osaka, Japan　

           13 CCD Images (2, 3#, 4#, 9#, 10#, 14# December 2003)

                f/84×20cm Dall-Kirkham & f/40×60cm Cass# with a ToUcam

                                                      # Sakai City Observatory

    

MELILLO, Frank J (FMl)  Holtsville, NY, USA

         　 1 Red CCD Image (5 December 2003)  

20cm SCT with a Starlight Xpress MX5

    

MINAMI, Masatsugu (Mn)  Fukui, Fukui, Japan

           14 Drawings (5, 10 December 2003)

 600, 480, 400×20cm F/12 ED Goto refractor*

                           *Fukui City Observatory, Fukui

    

MURAKAMI, Masami (Mk)   Yokohama, Kanagawa, Japan

　　　　 　11 Drawings (2, 10, 14, 15 December 2003) 320, 400×20cm spec

    

NAKAJIMA, Takashi (Nj)  Fukui, Fukui, Japan

            2 Drawings (3 December 2003)  400×20cm F/12 ED Goto refractor*

                                                         * Fukui City Observatory, Fukui

    

PARKER, Donald C (DPk)   Miami, FL, USA

            7 Sets of CCD Images (5, 9, 13, 14* December 2003)

                     f/55, 59×41cm F/6 spec equipped with an ST-9XE/

          　　　　   *f/19×32cm SCT with a ToUcam

(with T D'AURIA and S FAWORSKI)

    

PEACH, Damian A (DPc)  Loudwater, Buckinghamshire, UK

            1 Set of CCD Images (+ 5 Set Images) (9, 15 December 2003) 

                               f/31×28cm SCT with an ATK-1HS

　　

PELLIER, Christophe (CPl)  Bruz, Ille-et-Vilaine, France

            1 Set of CCD Images (+3 IR+B Images)(7, 14+, 15+ December 2003)

                18cm spec/35 cm SCT+ with a modified B&W ToUcam Pro

    

SIEGEL, Elisabeth (ESg)  Malling, Danmark

            4 Drawings (6, 9, 10, 15 December 2003)  270×20cm F/10 SCT

    

TEICHERT, Gérard (GTc)   Hattstatt, France

            3 Drawings (7, 8, 9 December 2003)  330×28cm SCT

　　

Van Der VELDEN, Erwin (EVl)  Brisbane, Australia

            3 CCD Images (1, 10, 12 December 2003) 

 f/31×20cm SCT with a Vesta Pro modified

 

T

he Minimal South Polar Cap: On 5 Dec (λ=311°Ls), DPk gave nice R images at ω=111°W, 117°W where the spc is shot small but clearly: As suggested by T SAHEKI long time ago the season at λ=310°Ls is critical, and so we can regard the R image of the spc on DPk’s as a final residual one. ESg also felt the spc was as if suddenly small on 6 Dec after the preceding observation on 28 November: On 9 Dec (λ=313°Ls) at ω=324°W she observed a circumpolar polar haze from 30°S southward by Int.

 

IR Images before Sunset: Ak obtained on 8 Dec (λ=312°Ls) an IR image at before 3 o’clock PM (more exactly at 14:30 JST (5:30 GMT, ω=178°W) and several before Sunset. On 13 Dec, he started further earlier from 13:55 JST (4:55 GMT). Visually the present writer (Mn) was able to get image just half an hour before Sunset at 16:00 JST on 10 Dec, and so we feel such a trial through IR light before sunset (or after sunrise) should be fruitful.

 

DPk’s Detection of a Significant Dust Storm on 13 Dec (λ=315°Ls): A clear large dust storm was found by DPk on 13 Dec at ω=072°W (01:35GMT) which expanded from Chryse to the wider area around Eos, covering half of Aurora S, further detouring to Candor, and southwardly reached the northern part of Argyre,. DPk also suggested another core at Aram. He chased up to ω=092°W. Since the phase angle ι was 42°, Aurora S was 80° after the dawn (before the noon) by the time, and the following area of Soils L was still free. DPk’s email arrived at 16:31 JST. Since MURAKAMI (Mk) of cmo@ was not at home, the present writer (Mn) sent out CMO Notice #07 informing DPk’s dust event by the use of the CMO mailing list (maybe bigger than DPk’s) at 18:38 JST (Japan Standard Time). At around 20hrs JST, Mk returned home and he readily uploaded DPk’s images on the CMO-Gallery and put an alert on the CMO Façade Window (Director's Notes). For the time, the observations should have been done at the US, but the dust was seen already on the afternoon side there, we were anxious about the observations made in Europe. However, if it was possible to chase up to 21 hrs GMT in Europe, the angle was up to ω=355°W (really CAPARRÓS (ACp) made an observation on 12 Dec at ω=333°W), it might have been hard to catch the morning dust. On the other hand in Japan, the angle was ω=166°W at 17 hrs JST (around sunset) and so we were to just wait. However by chance Ak started, as aforementioned, from 13:55 JST through IR-980, but unfortunately the images were unstable first until the latter one at ω=162°W: However the position of Aurorae S + 90°W implied 150°W, and hence it was impossible to detect.

　On the following 14 Dec (λ=316°Ls), DPk produced an image with D'AURIA and FAWORSKI at ω=044°W (00:19GMT), and COLLVILLE (BCl) in Canada at ω=047°W (00:30GMT): The dust looked largely expanded or stayed at higher altitude, and showed several new dust cores at Eos, Capri Cornu, and also at the west of Argyre. On the day Ak succeeded in catching the west end of the dust at ω=111°W (4:56GMT=13:56JST) in IR, and KUMAMORI (Km) also caught it at ω=118°W(5:23GMT=14:23JST) by the use of R-640. The western end of the dust was near the centre of Solis L, and the southward end reached to the west of Aonius S making a bright core. Ak was eventually able to compose an RGB image at ω=145°W (7:15GMT=16:15JST), where the core was light also in B. Ak also visually checked it at around 15:30 JST (around ω=130°W). Km also made a colour image at ω=152°W (7:45GMT) where the dust was still evident. Km chased until ω=167°W: still a trace was seen. MURAKAMI (Mk) visually tried at 9:00GMT (ω=171°W), but just saw it like a bright limb haze.

On the evening, Ak readily processed, and sent the images to us at 20:06 JST: So we emailed out his result to the world-wide CMO members at 20:52 JST (=11:52GMT). DPk’s correspondence saying Congratulations to Tomio! reached us at 4hrs GMT on 15 Dec. Km’s images arrived at 3:29 JST on 15 Dec. We also received a reply from RMk on 14 Dec at 19:07 JST, and he communicated the dust was reminiscent of the European dust in November 1990 (λ=326°Ls). He also suggested the onset might be too late for the dust to be global. On 14 Dec, PELLIER (CPl) in France made an image at ω=313°W (18:42GMT).

  On 15 Dec (λ=316°Ls), GRAFTON (EGf) made a set of clear images at ω=038°W (00:36GMT): The dust at high altitude seemed to be remnant to the extent that the western half of S Sabaeus as well as Meridiani S were faded, and a bright new core was seen to the south of Aram, and bright belt to the east of Argyre, and also several small cores at Eos and Capri Cornu. It was notable however that the lowlands of Niliacus L and M Acidalium were not deformed and looked as usual, and just haunted by a white haze independent of the dust cloud. Further notable was that the B image showed a bright core at the morning Argyre and its west implying a condensate patch associated with the dust.

In Japan, Mk started from 16 hrs JST by a 10cm equatorial Nikon refractor and made an observation at ω=151°W (17:20 JST=8:20 GMT) by the use of the 20 cm Saheki Newtonian. The dust was clearly seen covering the area of Solis L to the south while the dark markings around Daedalia were visible. He chased thus at ω=161°W, 171°W, 181°W as the dust was gradually pushed to the rear side. Ak obtained the RGB images at ω=166°W, 180°W. The dust part was light in B. In Europe, CPl produced a set of excellently detailed images for δ=9.7" at ω=295°W (18:10GMT) by the use of C14: They are interesting since Noachis and M Serpentis are a bit seen at the morning side. In B, the morning part of the southern Noachis shows a patch down to the area of M Serpenris. On the same day, ESg saw a light area by Int at the morning Noachis at ω=292°W (18:00GMT), but in W47 she felt lighter part rather northward.

 

  MGS-MOC Observations: Apparently the images of DPk on 13 Dec shows that the dust storm is slightly not fresh considering the expansion: Really the dust chart on the preceding 12 Dec (λ=314°Ls) made by TES (http://tes.asu.edu/dust/dust.mov) shows already a rise of dust cores near Chryse and Eos. The MGS-MOC wide angle images, shown here, prove certainly a full of dust at the southern Chryse and Eos to Valles Marineris. The MOC images also show several dust distributions on the preceding days, but as far as we depend on the TES images we may be suggested to regard that the essential dust having a potential remnant dust was onset on 12 December. As repeatedly we stress, the Martian dust disturbance does never propagate like the Hurricanes or Typhoons, and the initial latent one rather subsides at the night side, and makes a new one rise in the next morning discontinuously (maybe at a different place), and so we cannot easily trace the relationship among several dust disturbances before 12 Dec. TES suggests a dust disturbance near at Tempe on 4 Dec (λ=310°Ls), and it became again latent next day, but this may be regarded as a precursor, and may be said to have developed to the cross-equatorial dust storm in a week.

The TES image on 15 Dec proves the position of the south-western end of the dust as well as an existence of a bright core near Dia which matches the observations by Mk and Ak on 15 Dec. The MGS observations are made at 2 o’clock PM, while terrestrial observations show well the morning side: It is interesting and may be important to see that the morning condensates are conspicuous at the latitude around 60°S while the afternoon TES shows a new steady core at around the area of Dia.

 

T

he next issue shall treat the observations made in the Second half of December 2003 from 16 December (λ=317°Ls) to 31 December 2003 (λ=326°Ls, δ=8.5").

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