Tuesday, June 12, 2012

Venus Transit Images

As documented in my Expedition Notes, I was on the summit of Haleakala for the 2012 Transit of Venus.  Here are a couple of representative images.  First, the beginning of the transit, in white light - a stack of 10 images taken with a Canon EOS 40D and aligned and processed in Photoshop.  Click on the image to see it full-size:


This is the color of light the Sun puts out.  It is not yellow or orange - people only think it is because the only time you can actually stand to see the Sun is when it is rising or setting, especially through clouds (and it is still not safe to look at it this way!).  At those times, the light is significantly reddened from the passage through very thick layers of air and dust.  Note the sunspots and other details - white light is interesting.  But what is *very* interesting is Hydrogen Alpha light.  This image of the end of the Transit is a stack of 7 images taken with a Sony NEX 5N camera and aligned and processed in Photoshop.  Again, click on the image to see it full-size:


Hydrogen Alpha is a specific wavelength of red light emitted by Hydrogen when one of its electrons makes a specific quantum transition.  It is used because it shows very different details than white light.  Notice again the sunspots - they are not quite as visible.  However, much more surface detail is visible on the disk of the Sun.  In addition - notice the (heavily-processed!) red flames around the disk of the sun.  These are real - they are called "prominences".  The exposures I was taking were not optimized for prominences, so there is not much detail there - but you can see them!  I chose an orange color for this image because, to my eye, I can see more details than I can with a pure red image.

Finally, I assembled an animation of 75 images from both scopes, side-by-side.  The left (red) image is the Hydrogen Alpha image and the right is the white light.  Apologies for the shakiness - I'm still on vacation and my laptop is the only tool I have available.  Perhaps some day I'll make a much nicer, smoother video:




And that's about it for now. Stay tuned, I may play with this data some more in the coming weeks...

June 25, 2012 edit: Edward Plumer, my brother-in-law, has posted his observations on his blog.

Venus Transit Expedition 2012

This year, we planned a family outing to Hawaii.  Being a science geek, I said, "If we are going to Hawaii this summer, let's make sure we are there on June 5 for the Transit of Venus".  Hawaii is one of only a couple of spots in the United States where the entire transit would be visible.  And so, we chose early June for our vacation.  Our target was Maui; specifically, the summit of Haleakala, the highest peak on Maui:


View Larger Map

We chose Haleakala for several reasons.  First, Maui is indeed a tropical paradise, an excellent spot for a family vacation.  Second, at 10,023 feet, Haleakala is almost always above the clouds.  Finally, we anticipated that the world + dog would descend upon (ascend up to?) Mauna Kea on the Big Island, making it very difficult to find a good spot to set up telescopes - in fact, we heard later that only shuttle buses were allowed to the summit, so we were quite likely the highest-altitude amateur observers of the transit on Hawaii!  Possibly even the highest-altitude amateur observers in the United States?

The hard part about going several thousand miles for an event like this is figuring out what equipment to bring and how to get it there.  I decided on the following main components:


  1. A Baader Herschel Wedge attached to an Orion ED80T telescope (80mm f/6 apochromatic)
  2. A Coronado Personal Solar Telescope (40mm f/10 monochromatic Hydrogen Alpha)
  3. A Canon EOS 40D (attached to the ED80T/Herschel Wedge via a 1/2x Barlow + T Ring)
  4. A Sony NEX 5N (attached to the PST via a 1/2x Barlow + T Ring)
  5. An iOptron Minitower Pro alt-azimuth tracking mount


This is a substantial amount of equipment to schlep about.  The scopes and cameras fit into a carry-on camera backpack, but the mount does not, and it is rather heavy.  And I did not want to drag it through the airports in Denver, Maui, Kauai, Oahu, ...  So I built a crate to fit, using construction insulation foam as structural material to hold the tripod legs in place:


The crate got sealed up, and sent UPS:


There were anxious moments as I had mis-addressed the crate to the wrong resort management company.  However, UPS was very helpful, and I was able to retrieve the crate from near the Kahului airport.  I of course immediately set it up to make sure it was functioning.  Here is everything attached with Maalaea Bay and Kahoolawe in the background:


The next morning we were up near dawn, and my sister, her husband, and I made the long trek up to the top.  The target was the building on the very summit of Pu'u Ula'ula - Red Hill - at 10,023 feet:


This was almost certain to be above the clouds.  Unfortunately, it was also several hundred feet and about a mile distant from the restrooms:


The views from the summit are stunning.  Here is a view down into Haleakala "Crater" with clouds roiling about the edge (we later learned that most other viewing on Maui was mostly cloudy):


We got permission from the Park Service to set up our scopes in the lee of the summit building (it was very windy that day!).  You can barely see them set up in this photo:


Here is my setup (on the left) and my sister and brother-in-law's setup (on the right), shortly into the Transit (the scopes are nearly vertical):


Surprisingly, not many people were there for the transit.  However, fortunately, a science and math teacher from Seabury Hall (a local private secondary school) was there - he brought a Sunspotter, a great device for such events, and it showed the transit quite well (you can see the black dot of Venus on the projected disk of the Sun):


Although not many people had come up specifically for the transit, everybody who showed up was interested.  Between the SunSpotter and having people look through my camera viewfinders (plus a few other scopes that showed up as the day progressed) we managed to keep people informed.

The advantage of having two trusted teams of trained amateur astronomers is that you can take turns making the multi-mile round trip to the restroom.  On one trip, I spotted a Chukar near the visitor center parking lot:


The transit went spectacularly well - see the next post for some pictures and animations - we had clear weather until the very end of the day (notice that the scopes are nearly horizontal now):


After the Transit was over, I took the time to make a couple of panoramic photos.  Here is the shadow of the summit over Haleakala Crater:


And here is the view to the west - the buildings on the left are the US Air Force Maui Space Surveillance Complex:


As night fell, the big toys in the Space Surveillance Complex came out:


And that was our expedition.  Thanks to the whole family for making it possible, and thanks to my sister and brother-in-law for braving the summit with me!  Thanks, too, to all the curious travelers who shared the day with us.

We've been on vacation all the past week, so this is the first chance I've had to blog.  Apologies to anyone who has been waiting anxiously for the info... and see you again in 2117!

June 25, 2012 edit: Edward Plumer, my brother-in-law, has posted his experiences on his blog, and I've posted some processed images on the next post.