Transit of Venus, Not unmannedspaceflight but it's in space, so.... Options

[Guest_Oersted_*]

Btw, maybe UMSF needs to expand the Telescopic Observations sub-forum to also include observations of the inner and outer solar system? That way topics such as this don't fall between the cracks, so to speak.

[bkellysky]

Just north of NYC, we had two periods when the Sun shown through around the clouds.

Attached is photo at eyepiece of my 60mm (Kendrick solar filter) telescope at 28x (with the surrounding lawn, since I hadn't zoomed in yet). Handheld Canon XS 1/160sec, ISO 100.

I'll post more photos at my blog - two through the telescope, handheld up to the eyepiece; and others where I used the clouds as filters with my camera set at or near 1/4000 sec at F32, the fastest shutter speed and highest F ratio I could get on the Canon XS.

http://bkellysky.wordpress.com/
and other's photos of the event via our club site:
http://www.westchesterastronomers.org/


bob

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[ElkGroveDan]

I shot this directly using dual polarizing filters on a 300mm lens. The attachment is a 2x crop.

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[Explorer1]

SDO montage is up:

http://www.youtube.com/watch?v=4Z9rM8ChTjY

[jekbradbury]

JAXA's HINODE satellite (in sun-synchronous earth orbit) also took some impressive close-up images.

[ngunn]

SDO montage is up:

Hmm. The limb of the Sun appears to be visible 'through' Venus in some of those sequences. Is there some sort of memory effect in the detectors that would account for this?

[Floyd]

I see the effect particularly for the image where most of Venus has passed in front of the sun. It is a simple optical illusion and if you cover the bright lim of the sun with your fingers, it goes away.

[ngunn]

Check for example 33 seconds in (where the limb of the sun is actually dark). I've masked off the whole image except for Venus and I'm still seeing the effect.

[Explorer1]

Yeah, it really looks like detail on Venus itself, though of course that's impossible, even if it wasn't overcast there.

[JRehling]

The performance of human vision is a thing still not perfectly understood, and transits of Venus have brought up a lot of questions about where perception is accurate and where optical illusions occur. Digital imagery is slaying a lot of dragons on this count.

I was interested to have the chance to see Venus appear as large as ever it will, and see if I could resolve it as a disk with the unaided eye. I'd have to say no. Viewing it with a filter and no magnification, I could easily see where it was, but it appeared as pointlike (black against green) as does a star in the night sky (white against black).

In the night sky, I've tried to see if the angle of the crescent is apparent to me. Squinting and seeing if the twinkle has any persistent orientation. Nothing conclusive to report there, either. I have considerably better than average acuity, I should add. And I have seen Uranus without assistance on one occasion, although detecting dimness and acuity are not at all the same thing.

[ngunn]

It's not a big deal and I'm sure there's a mundane explanation, either from image acquisition or processing, but it's definitely not an optical illusion. Optical illusion would operate to make the silhouette look lighter against dark background and darker against light. This is the other way round: lighter against light and darker against dark, making it look spookily transparent.

[Hungry4info]

Could it have something to do with the CCD? Maybe it's been staring at the sun so long that an image of it has sort of been burned in? (I'm thinking of CRT monitors and how if you leave them on for too long, you get an image burned in, but I realise that's probably totally inapplicable to this).

[Guest_Oersted_*]

Hmm. The limb of the Sun appears to be visible 'through' Venus in some of those sequences. Is there some sort of memory effect in the detectors that would account for this?

I'd say that it is more probably an effect from the video compression. However, it is also visible in the "raw" video (example)...: http://venustransit.gsfc.nasa.gov/data/kio...n/phase/ingress

[Holder of the Tw...]

Got to watch the transit under perfect skies at Barstow, California. Mostly through binoculars, but also unmagnified. Pictures are just no substitute for a live view. I was surprised to see how quickly it became apparent after first contact.

As another member mentioned, one of my own strongest impressions was how impossible it would be to make out a Venus crescent naked eye. Even with 20/15 vision in my right eye, it was a pinprick unmagnified.

[bill davis]

Here is a cross view stereo pair of the Venus transit with some air traffic.

Bigger version on my Flickr stream.
http://www.flickr.com/photos/billdavis6959/