Mercury Transit 2006
I was able to observe the Transit of Mercury today -- which means that Mercury appeared to move across the face of the sun. The first time I saw one was in 1971 -- I've also seen the transits in 1993, 1999, and 2003. The next one will be on May 9, 2016.
With the Mercurian year so short, it would seem that the planet would appear to pass across the sun more frequently -- but for a transit to occur Earth, Mercury and the Sun must be on the exact same plain, which does not happen very frequently.
The weather made it challenging.
The skies were cloudy most of the day -- I only had about a 40 minute period of very sporadic moments to see the transit through openings in the clouds.
The photo below is an image of tiny Mercury moving across the face of the sun. Mercury is easy to see here, appearing as a tiny, distinct, black dot.
This image was taken in Calcium K light at 393.4 nanometers. The termally stable interference filters on this telescope allows one to view the chromospheric network of ionized calcium emissions that are created when supergranulation cells sweep through magnetic fields where they collect and strengthen. The emission line is not visible to the eye to all observers -- such as older observers -- "older" apparently applying to me :( -- so an imaging device to take photos is necessary.
The layer of gas that is visible in this image is cooler and at a lower level of the Chromosphere than the one observed with an H-Alpha filter.
The next photo shows the transit in H-Alpha light. The red light of hydrogen alpha with a wavelength of 656.3 nanometers allows one to see the layers up to 1700 km above the sun's visible surface. With H-Alpha filters, one can see the white areas around the black sunspots (called plages), as well as brilliant solar flares, filaments, and prominences.
The CaK and H-Alpha filter photos shown here were taken at the same time.
Because of the off-and-on cloudy weather in the Greater Atlanta area where I live, it was handy to be able to look through a telescope via the Internet. The telescope used an H-Alpha filter and was located in Arizona and was available through www.Slooh.com -- which usually offers a remote telescope viewing from the Canary Islands, off the coast of Africa. I found it difficult to capture images from this set up -- and finally just grabbed a digital camera, aimed it at the monitor, and shot this image.
I also had a friend in New Mexcio, and he and I were each other's "Plan B" in case of cloudy skies. We had arrangements to look through each other's telescopes via the Internet. I got the better end of the deal -- with the brevity of my own clear skies, I did not have the time to broadcast any of my views online, nor did I have the time to turn on an electronic eyepiece in order to make videos of the tranist. There were several online sites showing the transit -- besides looking at www.Slooh.com, I also wached part of the transit live from Japan. I tried to watch Kitt Peak Observatory, but I kept having to refresh that web page and it would not always refresh efficiently.
I took quite a number of other images, and may post more later.