transit – Page 2 – A Darker View

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…

Venus Transit Second Contact — Transit of Venus 2012, second contact at 12:27pm

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

Viewing the Transit of Venus on Mauna Kea

Everyone is gearing up for the Transit of Venus. Starting at just after noon on June 5th, Venus will cross the face of the Sun. This will be our last chance to see such an event in our lifetimes, as a result, many skywatchers are making an extra effort to see this transit. This includes a number of folks who are traveling to Hawai’i this June, just to be here for the transit.

The Office of Mauna Kea Management and and Mauna Kea Support Services are making an extraordinary effort for the transit. An interesting exercise, protecting the mountain, ensuring everyone is safe, and allowing reasonable access to the summit. This is a challenge under normal circumstances. Throw in the possibility of a much larger crowd and it could be a real problem. Thus, the following extra measures will be in place…

The summit access road will be closed to public vehicular traffic at the Visitor Information Station.
Access to the summit will be provided via free shuttle service between the Visitor Information Station (VIS) and Mauna Kea summit.
Parking at the Visitor Information Station (VIS) is limited. Additional parking will be provided, however If parking spaces fill up, vehicles will be held below the VIS until parking becomes available.
Mauna Kea Rangers and Hawaii County Police Officers will be present to assist with parking and public safety.

There will be solar telescopes stationed at the MKVIS, at the summit, and at a number of other locations around the island. With many options to choose from, you do not need to go to the summit to get at least some view of this event.

The diehards, those wanting to see the entire transit, will probably go to Mauna Kea. I really do not know what sort of crowd to expect on the mountain. While it could be substantial, I really expect a more modest showing than some folks are predicting. In any case it will be a fun event.

Myself? I will be on the summit. I will be running the Keck live webcast of the event using one of my telescopes. From a vantage point behind the Keck 1 telescope we should be in position to witness the entire event from start to finish.

Transit of Venus Timing

For reference I am posting precise transit timing for the June 5th Transit of Venus. The data is taken from Fred Espenak’s wonderful NASA Eclipse Website. I just extracted the cities that are of most interest to my Hawaiian readers. For the full list of US cities you can go here.

As you might notice, the times change by a mere two seconds between Kona and Honolulu. These times will be pretty close for the entire island chain. That last number is the Sun’s altitude, the angle above the horizon. Note that this is near 90° for Hawai’i, nearly straight up for the start of the event. Final contact will occur with an altitude of about 5°, just above the horizon near sunset.

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 are local time. Keep in mind that this event occurs on June 5th for viewers in the US and Hawai’i. Some sources show June 6th for a date, and so it will be for viewers on the other side of the date line in Australia, Japan and China.

Viewing the Transit of Venus on Hawaii

There is only one more chance in our lifetimes to see a Transit of Venus. If you are curious about this event, where do you go to see it?

Hawai’i is well placed to see the entire event. The transit starts just after noon, with the sun high in the sky. As the transit ends just before sunset, a clear western horizon will be required to witness final contact. For the true astronomical diehards, the summit of Mauna Kea will be the destination. With a clear view, above the clouds, the entire event will be visible.

For those folks who just want a nice view of the event, and do not necessarily need to watch for the entire seven hours, there are a number of easier options. To accommodate the public, there will be solar telescopes setup and manned by volunteers at a number of locations around the island…

Mauna Kea Visitor Information Station (MKVIS) A portion of the VIS parking lot will be converted into a viewing station. Telescopes with solar filters will be available. A NASA-sponsored live web cast of the Transit will be displayed inside the VIS and in the presentation room. Parking space at the VIS is limited. If parking fills, vehicles will be held below the VIS until parking becomes available. You may want to consider some of the other sites listed below.
ʻImiloa Astronomy Center of Hawaii, Hilo ʻImiloa will display the NASA webcast of the Transit. Leading up to the day of Transit, ʻImiloa will also be running a special planetarium show titled “When Venus Transits the Sun.”
W. M. Keck Headquarters, Waimea Livestream from the summit at headquarters in Waimea. Headquarters will be open until 6 p.m. Solar telescopes will be available. Free solar cards for viewing the Transit directly will be provided, while supplies last.
Canada France Hawaii Telescope (CFHT), Waimea Solar telescopes and a sunspotter will be available for the public. A raffle for a copy of “Hokuloa: The 1874 Transit of Venus Expedition to Hawaii” by Michael Chauvin will also be held.
Puʻu Koholā Heiau National Historic Site, Kawaihae From Noon till 4:30pm. Special glasses will be available, and a live webcast from the summit of Mauna Kea in the Visitor Center theater. As well, park rangers will give special presentations about the historical significance of this event throughout the day.
Natural Energy Lab in Kailua-Kona Mahalo to the Natural Energy Lab for sponsoring this event!
Keaʻau In the lot across from the Fire Station, Mahalo to W. H. Shipman Ltd for sponsoring this event!

Venus Transit

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.

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