Mercury Observing - Page 3

iceman (Mike) · #41 06-05-2005, 06:13 AM

Thanks for the comments guys. Erwin or Steve, do you use a filter to image Mercury as it comes into daylight? I've heard that a red filter is useful.. is that true?

ErwinvdVelden · #42 08-05-2005, 04:40 PM

Mike,

I image with a colour chip, so I'm using an IR+UV blocking filter only. With a monochrome camera a long red pass filter is very useful.

Cheers,

ErwinvdVelden · #43 10-05-2005, 03:15 PM

Hi everyone,

I've been up every morning to check the weather.

Last Thursday was cloudy, on Friday I went way west to escape the clouds, clear most of the night but cloudy early in the morning.

The same on Saturday, did a lot of deepsky imaging

, but... overcast on Sunday morning, with only a few glimpses of Mercury before sunrise.

I got back on Sunday and cloudy on Monday, as wel as today

And the forecast for this week really stinks, for me at least.

The more attentive reader should have noticed a hiatus in this emoticonical essay by asking himself what happened last Friday.

I'll let you know more about that one late tonight...

Cheers,

ErwinvdVelden · #44 10-05-2005, 11:16 PM

Hi everyone,

Here as promised the Mercury shot of last Friday. It's a stack of 8000 frames made under a very transparent sky with a reasonable seeing, the latter doesn't happen that often when imaging Mercury.

This image shows the suspected Skinakas Basin as a dark area in the Southern Hemisphere.

The skies should clear by Friday, hopefully I can pull another observation in.

Cheers,

Dennis · #45 11-05-2005, 06:23 AM

Wow Erwin - that is a stunning image. Good job!

Cheers

Dennis

PS - Now tell me that you didn't sort the 8000 frames manually!

iceman (Mike) · #46 11-05-2005, 07:23 AM

That's an awesome shot Erwin, the image scale is fantastic. 8000 frames! Holy cow! Do you image at 10fps?

How many frames did you capture, to stack 8000 of them? Can you post a stack of say 500 framesto show the difference? Is it just grainier?

ErwinvdVelden · #47 11-05-2005, 10:25 AM

Hi folks,

Handsorting this amount of frames would be a solid 6 hours of work, which I used to be quite happy to do. The gradient selection in Registax however works pretty well nowadays, this compared to the older selection functions that weren't capable of making any sense out of the low contrast day time images.

I noticed however that as long as the AVI is shot exactly in focus, better results are being obtained when using all the frames. I tried a selection of 2900 frames, but the result is just much noisier.

I'll post a 500 frames stack tonight for comparison.

The 4 AVI's are shot at 5 fps, 2000 frames each.

I also put the scientific version on the web, see

http://tinyurl.com/bysvy

It contains a comparison of the two different data sets.

Cheers,

videoguy · #48 11-05-2005, 08:12 PM

Well done on the Friday image Erwin - glad you finally got some good weather. That's a nasty band of cloud hovering around the north.

I've attached below a animation showing both our recent images and the relative movement of surface features.

Also obtained some rough results through thin cirrus cloud this morning which (when I get around to it) will add nicely to this animation.

ErwinvdVelden · #49 12-05-2005, 12:41 AM

Hi Steve,

Looking very good! It is definitely rotating! Saturday is going to be clear here, maybe I can add another one.

Cheers,

Erwin

iceman (Mike) · #50 12-05-2005, 08:03 AM

Very nice images, Erwin and Steve!

rumples riot · #51 12-05-2005, 01:25 PM

Very nice images gents, a very difficult target and one that presents a little too much danger for me. Been flashed by the Sun once and have learnt my lesson. I know that Mercury is quite a distance from the Sun at present but am glad that you guys are doing this. Keep those great images coming.