LtE in CMO #289

From Frank J MELILLO

. . . . . . . . .Date: Tue, 24 Feb 2004 10:03:43 -0500

Subject: Venus in UV light: February 23, 2004


Dear all -

Venus was imaged again in UV light February 23, 2004 at 23:44 UT. This time, Venus was taken alot lower in the sky than the day before.  


The seeing was OK but not great. Venus changed dramatically when comparing it just 26 hours ago. Whatever it was on the limb on the 22nd, it should be on the terminator the next day (23rd). A slight shading was seen on the terminator along with very faint markings.


. . . . . . . . .Date: Sat, 28 Feb 2004 00:57:18 EST

Subject: Venus in UV light: February 27, 2004


Dear all-

Venus was imaged in UV light February 27, 2004, at around 23:49 UT. It was a lot lower in the sky about 30 degrees above the western horizon. Normally, I imaging when Venus is at least 50 degrees up.


The seeing was fair. Venus displayed a faint marking just above the center on the terminator. I will image more tomorrow and Sunday.  


. . . . . . . . .Date: Mon, 1 Mar 2004 00:46:05 EST

Subject: Venus in UV light: February 28 & 29, 2004


Dear all -

Venus was imaged February 28th and 29th, 2004. The seeing was OK about average.  


On both days, the details are not as prominent. Just some faint markings near the center of the terminator. Nothing like the February 22nd observation which is at the bottom of my Venus website.


. . . . . . . . .Date: Mon, 08 Mar 2004 13:48:05 -0500

Subject: Re: Venus, March 8, 2004


Tom -

Thanks for posting your latest images of Venus March 8th.

I was planning to image Venus also on Sunday, but it got cloudier.

I was looking at your blue image very careful. You might have captured some markings which they are very faint. When I moved away from my screen, I can barely make out the bands especially just south of the equator and near the SPR.


I must say the 'Channel blue' filter you are using is showing the features very weak in contrast. I believe the Toucam is not sensitive enough to go to the UV region. That where action is. I don't know if your webcam has a CCD chip. Also, do you use an infrared blocker filter for your blue image?


. . . . . . . . .Date: Tue, 09 Mar 2004 16:32:31 -0500

Subject: Re: Venus march 1st and 8th


Christophe -

Excellent!! Especially on March 8th, there is a possible 'psi' may be seen! Hopefully, you can image tomorrow to see the difference!


Speaking of the IR 1000 filter, I wouldn't be surprise if it is blank all the time like you said. Venus' details in IR is very rarely seen. You are penetrating deep down through the atmosphere which is very plain most of the time. The big difference that the sulfic acid clouds, which is the UV absorber when exposing to sunlight, transfers to the top of the atmosphere and it appears darker. Usually in a shorter wavelength like in UV, we can pick up easily.


Even when I imaged in methane light at 890nm a few times before, it showed no detials.


But you never know...


. . . . . . . . .Date: Fri, 12 Mar 2004 14:08:15 -0500

Subject: Venus in UV light: March 11, 2004


Hi all -

Venus was imaged unexpectedly in UV light on March 11th at 23:41 UT.  


OK, but not much details to be seen.


. . . . . . . . .Date: Thu, 18 Mar 2004 01:23:03 EST

Subject: Venus' animations updated


Dear all planetary observers-

I have updated my Venus website with more animations. Thanks to Jamie Cooper of England on February 28th and Jason Hatton of California on March 13th - 14th. Of course, you will see Christophe Pellier of France and I which we made our first animation on February 8th.


These animations reveal much more information about Venus' clouds structures and the atmospheric rotation. It is obvious that the features are moving from right to left (from the limb to the terminator). I think this is the best way for our studies which I prefer nearly simultaneous observation.


I would like to do more of this type of work before Venus gets too thin later in May. Perhaps, as many as few of us can image Venus within the same day that spans nearly 9 hours, say from France/England to California to see the full effect of the rotation. So far, as little as 3 1/2 hours apart, the rotation effect can be seen. But, much more obvious at 5 hours apart.  


I am happy to see that more observers are interested Venus in UV light as never before. Still, much more work are needed to be done to understand the mystery of the planet's delicate features.


. . . . . . . . .Date: Fri, 19 Mar 2004 11:58:07 -0500

Subject: Re: Venus march 16th and an animation


Christophe and all -

Excellent!!! With such a high resolution, even at one hour interval, the rotation is noticable! You have done a spectacular job!!


With all my experience of observing Venus, it is the first time ever that I have seen the rotation of Venus. This is remarkable and this was never been done before. I think it is one of the greatest planetary work ever being done by amateur astronomers today. I believe the animation is more eye-catching to capture the delicate features and we have proved it! By doing this type of work, I think it is the most challenging and rewarding experience of imaging Venus this way.


I'm pretty sure the Venus coordinators Julius Benton of ALPO and Mario Frassati of BAA agree and happy with our work!


. . . . . . . . .Date: Wed, 24 Mar 2004 00:49:19 EST

Subject: Venus - March 23, 2004


Dear all -


Venus was imaged March 23rd between 20:09 UT and 23:05 UT. The seeing was OK.


Both images are roughly three hours apart. My intention was to make an animation to see a possible small shift of the rotation. Unfortunately, Venus' markings were pale and no definite patterns were seen. I couldn't make out any changes in three hours difference and also the seeing varied much of the time. So, no animation.


Frank J MELILLO (Holtsville, NY, USA)

Director, the ALPO Mercury Section


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