LtE in CMO #271

FromChristophe PELLIER

@ . . . . . . . . . . Date: Tue, 8 Apr 2003 18:36:20 -0000

From: "Christophe Pellier" <>

To: <>, <>

Subject: My contributions to CMO / OAA

Hello Masami Murakami and Masatsugu Minami,


I send you my first contribution to the CMO work. I have been a regular reader of the OAA/CMO web site for a few years, and now I would like to participate to this wonderful work. I would like to apologize for the low quality of this first image, but I live in France and as you know, conditions until may/june will remain difficult to observe Mars as it's not so higher that it was in 2001! Despite of this I wanted to begin early my observations. The 2001 dust storm, that year, kept me hanging behind my eyepiece every clear night and despite of the current seeing adversity, it's a nice feeling to begin observing the planet again. I have been interested in planetary observations for 8 years, and now I'm working in the SAF (Socit astronomique de France), mainly in the Jupiter section where I have taken a few responsibilities, but I'm interested in every planet.

I hope to send you better images as the apparition goes on.

Best regards,


@ . . . . . . . . . .Dear all, here is my first Mars image of the current apparition. It has been taken under very poor conditions as the planet is still low above the horizon, nonetheless it counts for an "observational report". A drastic selection of 170 frames among 1400+ (3 mn avi file) and a red filter have permitted to reveal a dark Syrtis Major, Sinus Sabaeus, and even Hellespontus. The SPR displays too white patches, but this is likely to be an artifact. Best regards

(9 April 2003 email)


@ . . . . . . . . . .Date: Wed, 9 Apr 2003 21:32:02 -0000

Subject:My contributions to CMO / OAA


Dear Masatsugu,


thanks for your message. Yes, it's important for Mars that observers are situated all around the world, and I will try to observe the planet as much as I can. I remember that some information may have been lost in 2001 because Europe was unfavuorably placed !


My current location is situated at 4801'N latitude and 00144' longitude. I would feel honored to receive a paper copy of CMO !


About the blue images, I know it's very important for Mars and I'll try to make some, but it may be very difficult for me to do so, for many reasons. The most important being that I work with a small diameter at a high F/D ratio, and the blue filter I have (W38A) absorbs much light. This winter I tried to image Jupiter through color filters, and I could never have an image bright enough with that filter. One average solution could be to show the blue component of a color avi file of the webcam, but it doesn't displays the corrects wavelengths, and with the planet low in the sky, it's completely destroyed by atmospheric dispersion... In fact, for a while, I'm afraid that the red filter (W25A) will be my only mean to have some details in the images. Sometimes observing conditions require hard adaptations from part of the observer...

Best wishes


@ . . . . . . . . . .Date: Thu, 10 Apr 2003 11:01:22 -0000


Dear Masatsugu,


many thanks for sending me the next CMO issue. I will try to obtain blue images. If so, it may be easier to make a color composite while the results with color avi files are not good enough. However, conditions must rapidly improve in may because the planet will get higher and its diameter will increase rapidly. If you have any information from Dr Okano, please let me know !

Best wishes


@ . . . . . . . . . .Sent: Wednesday, April 16, 2003 8:25 PM

Subject: Mars april 16 - bright areas ?


Hello everyone, Here are a few images taken this morning, again under very poor seeing, nonetheless they reveal unexpected features as these bright areas visible on every image, with a dark patch at the center. This looks like dust (bright in red) but this is quite puzzling in this martian season, and I'm not sure of what I see. The bright areas are yet visible on the raw frames so they mustn't be processing artifacts. I was thinking about Syrtis Major encircled by simple white clouds but it's a bit early to see it so "far" from the limb and how can white clouds be visible in red ? I tried also to get a blue image following Masatsugu's advice, but as expected, it has been impossible to use the W38A filter (too dark) ; so I tried a light blue one with two W80A filters stacked together. It's better than nothing but not good from a wavelengh point of view. Any comments would be most welcomed about this set...


@ . . . . . . . . . .Subject: Mars image, april 17


Seeing was even poorer this morning, with very low transparency... The bright areas are still visible but maybe they are merely brighter parts of the deserts. Some evening clouds are visible. The RGB image can show you how bad are the current observing conditions on Mars !

Best regards

(17 April 2003 email)

Christophe PELLIER

(Bruz, Ille-et-Vilaine, France)


Back to the LtE Home Page

Jump to the LtE Archives


To the CMO Home Page