Venus Dec 26th 2008

[mike bacanin]

I observed Venus today at around 4-30pm until 5-15pm. I had left the scope out to cool with the vents open for an hour.

The planet appeared slightly over half illuminated against the background sky,( i checked after and its around 57%), the seeing was quite poor initially making accurate focussing a challenge. I used a neodymium filter to slightly reduce the glare, but i think a blue filter would have been better.

I always find venus a bit disappointing visually due to its intense brightness even against the blue post sunset sky.

The best power was around x135 in my 9 inch sct, i also used x168 and x108.

i suspected a faint grey diffuse shading on the planet which appeared at several magnifications, but i think it was most likely a contrast effect.

Whilst it was good to view venus, i look forward to checking it out when the phase decreases to a crescent and the planet apears larger in a month or two. I want to look out for the mysterious "ashen light", an effect similar to earthshine when viewing a crescent moon.

I'll wait up for Saturn later tonight!

Mike

[thing]

Try a No. 47 filter. It will substantially reduce the glare.

[mike bacanin]

Thanks Dave, i'll look into that!

I just checked out some observations of Venus on Cloudynights.com.

The drawings look very similar to what i observed, so maybe, just maybe, what i saw were subtle cloud top shading. I would like to make further observations with the appropriate filter to be sure.

Mike

[thing]

It's a hard one Venus, with a 47 sometimes you think you can make out cloud shading but then you take another look an it's completely gone. I saw it as half phase earlier on tonight but totally featureless.

[mike bacanin]

Dave, sounds like an interesting and challenging observing project!

Some of the ccd images taken with UV filtering show a great amount of cloud top markings.

Mike

[thing]

The 47 (regardless of it's colour) isn't a UV filter as such, but it does block out tons of light and does enhance the contrast somewhat. I think so anyway.