Venus – Page 11 – A Darker View

The Transit of Venus

The plan was to stream the transit live from the summit. With access to the Keck facilities we had internet, a comfortable break room, and an excellent vantage point from which to view the entire transit. It sounded so easy at first, just put a camera on a telescope and connect it to the computer for the duration. Easy, in concept. The reality? Not so much.

It was an incredible amount of work. I had spent several days during the preceding weeks preparing the gear for transit. I admit some of that was fun, an excuse to get the gear out in the day and look at the Sun, even photograph Venus quite near the Sun.

The webcast team consisted of three people, Larry O’Hanlon, the Keck PIO, Mark Senft, a volunteer from our astronomy club, and myself. Larry and I met a HQ to begin our drive up the mountain at 8am.

At Hale Pohaku we picked up Mark and enjoyed breakfast. Here we found a massive buildup in progress, a gathering of troops… Visitor center staff, Hawai’i County police and fire, and the Mauna Kea Rangers, all present in force. Stephanie Nagata, the director of the Office of Mauna Kea Management helped man the roadblock. Stewart Hunter, the head of Mauna Kea Support Services with her in an orange vest. Their preparations looked to be necessary, three hours prior to first contact the crowds of transit tourists were already growing.

Observing the Aureole of Venus

Black drop effect? Bah! I observed a beautiful aureole effect in the minutes leading up to second contact.

The famous black drop effect is seen when atmospheric distortion of the image is quite bad. The effect plagued the early observers attempting to do transit timings. The effect is not seen when the atmosphere allows sharp views of the transit.

Instead, if the seeing is truly good, it is possible to see something far more rare, the aureole of Venus. This is a faint ring of light that has been refracted and scattered through the atmosphere of the planet.

I had not expected to see this, the appearance of the arc of light a complete surprise. But there it was… Very thin, quite faint, a sharp arc of light completing the disk of Venus. The view was steady, with nearly perfect seeing the arc was visible continuously.

Analyzing the observation afterwards I realize it was two elements that allowed me to see the aureole, the excellent seeing offered by the summit of Mauna Kea and good equipment. I was looking through my TeleVue 76mm telescope, using an 8mm Radian eyepiece and a Baader solar film filter. Very good equipment indeed, the optical performance of the system was not going to be a problem.

In the confusion and effort of running the Keck Observatory web stream, I was so glad I managed to free up the few minutes necessary to properly observe second contact. The sight was one of the most beautiful and sublime of any I have witnessed through an eyepiece in my many years of looking through a telescope.

I have been through my photos, nothing captured the faint arc of the aureole, no matter how I stretch the exposure. The best I can do is to record a few drawings in my observing notebook, a poor substitute for the beauty of the real thing…

Transit Of Venus 2012 Aureole — The aureole visible on Venus during 2nd contact, 2012 transit

Postcard from the Universe – Venus Transit

Transit is over, an exhausting and exhilarating day! I am headed to bed, but still totally jazzed with the experience. Keeping the webcast going for seven hours was a huge effort. Given the comments from our viewers it was worth it. I will have to more fully write up the experience for a later post.

The best visual for the day was the few minutes just before second contact… A beautiful, razor thin arc of light coming through the Venusian atmosphere, connecting the two horns of the occluded Sun. It was delicate and sublime, one of the most memorable sights I have ever seen through a telescope. With the excellent seeing of Mauna Kea, and the wonderful optics of my TV-76 telescope, the sight was clear and steady. I have yet to find a photograph that captures what I saw through the eyepiece.

I will post a quickly processed version of one of the frames from the second camera…

Transit of Venus is Today

The gear is tested, packed and ready. All of the arrangements have been made. It is time for the 2012 Transit of Venus!

We will be webcasting the transit live from the Keck telescopes at the summit of Mauna Kea. Tune in for images of the transit, and a lot of information about the transit. Larry O’Hanlon and I will be talking about the transit, the science, the history, and just generally enjoying the experience. You are invited to join us. Expect the broadcast to start about 11:45HST, or about 25 minutes before first contact.

Want to see for yourself? There are multiple locations around the island where you will find solar telescopes and volunteer guides to answer your questions about this event. Not on the Big Island? Check you local paper or look up your local astronomy club to find public events. Science museums, colleges, astronomy clubs and other astronomy organizations are organizing public events wherever the transit can be seen.

Location Name	External Sun Ingress Alt h m s °	Internal Sun Ingress Alt h m s °	Greatest Sun Transit Alt h m s °	Internal Sun Egress Alt h m s °	External Sun Egress Alt h m s °
Anchorage, AK	14:06:30 51	14:24:04 51	17:26:53 38	20:30:46 16	20:48:32 14
Honolulu, HI	12:10:07 85	12:27:46 89	15:26:20 49	18:26:38 9	18:44:38 5
Kona, HI	12:10:09 86	12:27:48 87	15:26:16 47	18:26:33 7	18:44:33 3
Los Angeles, CA	15:06:26 58	15:24:02 55	18:25:33 18	— –	— –
Phoenix, AZ	15:06:03 54	15:23:40 50	18:25:32 13	— –	— –
Portland, OR	15:06:05 57	15:23:40 54	18:25:53 23	— –	— –
San Francisco, CA	15:06:29 61	15:24:04 57	18:25:39 22	— –	— –
Seattle, WA	15:05:58 56	15:23:32 53	18:25:57 23	— –	— –

All times local. The data is taken from Fred Espenak’s NASA Eclipse Website. I extracted the cities that are of most interest to my Hawaiian readers. For the full list of US cities you can go here.

Please exercise caution when viewing the Sun! Use appropriate eye protection or indirect observing techniques to project an image of the Sun. The link at the start of this paragraph leads to a great discussion on viewing the Sun safely. As always the single best source on the web (or anywhere) for eclipse and transit information is Fred Espenak’s eclipse website at NASA. Stop by whenever you have a question on upcoming events as well as viewing and photography tips.

Venus Transit Thoughts

Tomorrow we will witness an astronomical spectacle that will not be seen again by anyone currently alive. The gear has been double checked, packed and loaded. Telescopes, cameras and computers are ready, with the exception of a few camera batteries awaiting their turn in the charger.

Imaging Venus in the Daytime — Testing gear for the Transit of Venus.

It is an odd sense of anticipation I feel. I have had the transit marked in my mental calendar for eight years, since I was unable to see the first transit of this pair. I have had a blog post written and scheduled for June 5th, 2012 ever since I moved to the island five years ago. Every time I logged into the administrator page, there it was, at the top of the list, ever so slowly growing closer. That day is here.

After a great deal of work, the gear is ready, a big source of apprehension has been dealt with. There is some doubt about the weather, with both high winds and possible clouds an issue. But there is nothing I can do about that. I can go into tomorrow and have fun with this event. It will be a very long and tiring day at the summit. Whatever happens, it will be a day for memories.

There is a new blog post entered now, for August 17th, 2017, another five years from now. On that day a total solar eclipse will sweep across the Pacific Northwest. We amateur astronomers schedule our lives a bit further ahead than most. I plan to be there.

Dress Rehearsal for Venus Transit

It was a full dress rehearsal. Both telescopes, two cameras, the entire streaming rig set up on the lanai. No less than three computers with cables all over the driveway! Surprisingly enough, everything went pretty well!

If you had been watching the Keck Transit of Venus stream, you would have been looking at a live image of the Sun for several hours. The seeing from my driveway was pretty poor, but there is a nice collection of smaller sunspots across the disk.

Everyone wandering by the house noted the telescopes. I gave peeks to our mail-lady and a couple young women who stopped by, intending to read me a bible verse or two (that was fun;)

Two technical issues were key today… Using thirty feet of active USB extension cables to run the streaming camera remotely, no problem. Co-aligning the two telescopes to aim at the same point, no action needed, aligned from the start. I had thought I might need to shim the mount for the piggyback ‘scope. I was also able to play with the streaming camera further. The Baader film filter gives a blue-white image. Adjustment of the camera white balance will restore a little yellow cast. I do not have much problem with the white, but a hint of yellow will allow people to instantly realize they are seeing the Sun. The same reason I adjust my processed photos for a golden orange hue.

We are all swapping gear around to get the set-up ready. Chris was nice enough to loan me a Canon T-ring and some Baader film. I built a battery pack and some sun-finders for several telescopes. Last night I picked up a whole solar rig from Cliff for delivery to Olivier. Olivier lent a 40mm eyepiece to Keck for the public telescope that will be setup at HQ. The list goes on…

I was not the only one doing a dress rehearsal. So far today I have been on the phone to other folks setting up and using a sunny Saturday to check gear. Some of the guys over on Maui even posted a video of their test run. I should have thought to do the same thing! Will have to time lapse the summit setup.

Venus Transit Reminder

This is your last chance this lifetime to witness a Venus transit! On June 5th the Earth, Venus and the Sun will line up correctly so that earthbound observers will see Venus cross the disk of the Sun.

Mercury Transit — Mercury transiting the face of the Sun, 6 Nov 2006

Venus transits are relatively rare events, that occur in pairs¹, with the paired events separated by eight years. Each pair is separated from the next pair in a predictable pattern, alternating 105.5 or 120.5 year gaps. The first transit of the current pair was in June 2004, with the 2012 event completing the pair. The next pair of events will begin in December 2117. Given the century long separation between events Venus transits have only occurred seven times since the invention of the telescope (1631, 1639, 1761, 1769, 1874, 1882 and 2004)².

To witness this event you only need to be on the daylight side of our planet when it occurs. The 2012 event favors the Pacific, Australia, Japan and eastern Asia.

For Hawai’i the event will begin at about 12:10pm with the Sun high in the sky, mid-point will be about 3:26pm and will end about 6:44pm, just before sunset. These times are only approximate, exact times will depend on the observer’s location and can vary by several minutes across the islands.

As always the single best source on the web (or anywhere) for eclipse and transit information is Fred Espenak’s eclipse website at NASA. Stop by whenever you have a question on upcoming events as well as viewing and photography tips.

Keck Observatory will be making an extra effort for this transit as Mauna Kea is perfectly positioned to observe the event. We will be webcasting the transit from a small telescope located at the summit. The webcast can be seen on your computer, or come over to our headquaters in Waimea to see the webcast and a live view in a solar telescope if the weather cooperates. there will be extra staff on hand to answer your questions.

Stay tuned to DarkerView for further details as the transit draws near.

1) Transit of Venus, Wikipedia Article, retrieved 8 Feb 2009

2) 2004 and 2012 Transits of Venus, Fred Espenak, NASA/GSFC, NASA Eclipse Website, retrieved 8 Feb 2009

Venus Approaching Transit

As we approach the Transit of Venus I decided to attempt to photograph Venus as a very thin crescent. I do not normally pay much attention to the planet, it is pretty when seen in the sunset. But when you turn a telescope to Venus it is quite boring, a white ball with no detail to be seen. I find I have been paying a bit more attention with the transit looming close on the calendar.

I could photograph the planet after sunset, but as Venus is quite near the Sun it would be very low in the sky and I would be shooting through a lot of air to get the imagery. Atmospheric distortion would be a major problem. The other method is to try something I had not done before, photograph the planet in the daytime, high in the sky and quite near the Sun.

Don’t try this at home?

Yeah, This will be a tricky operation. Venus will be only 12°44′ from the Sun, meaning I will have to be quite careful to avoid roasting my equipment, or my eyes.

I chose to use the 90mm APO refractor. With the optics at the front there will be some sunlight splashed down the interior of the tube. It should not be a focused image as it will hit the tube not even halfway down. There the heavy aluminum tube walls should dissipate the heat efficiently. The fully baffled tube should also stop much of this light before it reaches the camera. I may not have designed and built the optical tube with this sort of abuse in mind, but I did build it heavy, it will take it.

Venus 28May2012 — Venus on 28May2012, about 12°44' from the Sun

I located Venus by centering the Sun with the solar filter on the ‘scope. I then adjusted the setting circles and offset to the correct coordinates for Venus. After a visual safety check I removed the solar filter for a look. And there it was, a graceful and very thin crescent shining brightly against the blue sky. Replacing the eyepiece with a camera I focused and shot several video sequences.

The results? The final image can bee seen to the left. Not horrible, but it could have been better. The seeing at 11am was already starting to degrade, I am always amazed at how well the software can extract a half decent image from such distorted original material. The magic of sorting through and averaging a thousand frames. I wonder what I could do with better seeing.

Another try? Probably not, Venus is quickly getting closer to the Sun as we approach transit in nine days. The next time I photograph Venus it will most likely be silhouetted against the solar disk. Maybe an attempt after transit? I could shoot earlier in the morning with possibly better seeing.

Venus Exits the Evening Sky

Over the next week Venus will be lost to the Sun’s glare. It is currently about 15° east of the Sun, but getting closer quite quickly now and becoming tough to spot in the sunset. The planet will pass through inferior conjunction on June 5th. The planet will appear in the dawn sky around mid June. When it does appear, it will again be in the company of Jupiter which passed through superior conjunction on May 5th. The two will again dance with each other and the Moon in mid to late June.

Of course, this upcoming inferior conjunction is just a bit special as Venus will pass directly in front creating the Venus Transit.

Even when low in the sunset, Venus is worth picking up in a telescope. As the planet approaches inferior conjunction it shows an ever more crescent appearance to our earthbound vantage point. During the last days of visibility it will be a razor thin crescent, worth the effort to look.

A Thin Moon and Venus

A very thin crescent Moon will join Venus low in the evening sky tonight. The Moon will be a mere 4.3% illuminated. Both will be about 20% above the setting Sun and about 6%deg; apart. As Venus approaches inferior conjunction and transit, it too will be a thin crescent, about 6.5% illuminated. You will need a telescope to see the phase of Venus, but the beautiful pairing can be appreciated with the eye alone.