Andrew

Postcard from the Universe – Sol

Set up the gear again to get ready for Venus Transit. Attempting to autoguide on the Sun. No luck with the guiding, the software just does not like a non-pinpoint target. I did take a few photos in the process of messing about…

The Sun 19May2012 — The Sun on 19 May 2012, 90mm APO and Canon 60Da

Safe Transit Viewing

You have heard it before, but it really is true! Looking at the Sun for longer than a few brief moments with an unprotected eye can lead to permanent damage. Looking at the Sun with any sort of optical deceive that has not been properly filtered can lead to instantaneous eye damage.

Discussed below are the only safe methods I am aware of to view the Sun. There are some dodgy methods out there. Take chance with your irreplaceable eyesight? I think not. Be careful and do it right if you want a look.

For the unaided eye there are a couple options to view the Sun safely…

Solar Viewing Glasses Proper solar viewing filters are made from a thin plastic film, usually mylar, coated with metal to properly filter the Sun’s light for viewing with the unaided eye. These are widely available and quite cheap. Local astronomy organizations have been giving them away in preparation for the transit. Do not attempt to use these viewers in conjunction with binoculars or small telescopes, they do not provide sufficient filtering for optics!
Welding Glass Filters used for viewing welding offer much the same protection as solar filters. A shade 13 or darker welding filter can provide good protection for the unaided eye. Again, do not use a welding filter with any sort of optical device such as binoculars, they are not designed for such use and may not block enough light.

A much better view of the event can be seen if modest magnification is used. Do keep in mind that any soft of binoculars or telescope also concentrates much more light that the eye alone. Remember those childhood “experiments” involving a magnifying glass and ants? The best options here are the use of solar filters designed to be used on a telescope, or indirect means such as image projection.

Solar Filter — A solar filter mounted on a refracting telescope

Solar Filters for Telescopes Filters specifically designed for telescopes consist of either a plastic film, or a sheet of glass, coated with a thin layer of metal to block the Sun’s light. These filters pass about 1/1000 of one percent of the light. More importantly, they block the harmful infrared and ultraviolet light that could so easily cause damage. The filters can be purchased in many sizes as appropriate for various models of telescopes, costing between one hundred and several hundred dollars.
Image Projection One of the simplest methods of displaying a solar image is projection. A white screen placed a foot or two behind a telescope will produce a very nice image of the Sun that can be safely viewed by a number of people simultaneously.
Keep in mind that the beam of light out of the eyepiece is quite intense, potentially hot enough to burn a careless finger placed near the exit from the telescope.

The method works best with small optical systems, binoculars or the smallest of telescopes. You do not need big optics to project a very nice solar image.

You do not have any optics? Use the simplest optical arrangement of all, the pinhole camera!

If you do not have a safe means of viewing the transit and do want a look, you can go to one of the many public events being organized. Here on the Big Island there are quite a few options, one should be close to you.

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.

More Astronomy Haiku

Dark sky filled with stars
Telescopes help us see them
Takes your breath away
– Jennifer Sanchez

Space explorers
In the night implore
Please let it not rain!
– Mz’ili McKezfue (age 7)

Falling from the skies
In our scary, lonely nights
Brightening the sky
– Angelita Camacho

It is amazing how much can be encompassed in so few words.

Poems used with permission.

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.

Guard Crab

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!

Postcard from the Universe – An Active Sun

After years of a nearly blank solar disk, we have a beautifully active Sun. Any time you have a chance to see the Sun through a telescope this year, do so. The view is replete with sunspots, or if you have a Hα filter, prominences and more…

More Astronomy Haiku

Stars in the night sky
Keck Observatory sees
When was the Big Bang?
– Barbara Russell

Thanks to the work of a lot of astronomers and observatories, including Keck, we can answer that one… The Big Bang was 13.75 ±0.11 billion years ago.

Modern astronomy has allowed us to answer questions that have been asked for as long as curious humans have looked at the universe around us. Curiosity as expressed in a poem is part of what we are as humans. That is why we build and maintain the big telescopes. Thanks Barbara!

Preparing for the Venus Transit

Time to start preparing the gear for Venus Transit! This means dismantling the astrophotography rig in the garage and reconfiguring for solar work. Taking the the AT6RC telescope off and remounting the 90mm APO. The APO has just the right focal length to produce a nicely sized solar image on an APC-C sized sensor, such as the sensor in the Canon 60D.

First up? just setup the ‘scope in the driveway and take a few photos of the Sun. Just checking the photographic setup, the necessary parts and pieces. Nothing misplaced? Where did I store the solar filter? A nice focus on the camera? Perhaps take some nice photos of the large sunspots that current grace the surface of the Sun while I am set up. I hope we have some nice spots during the transit, they make focusing so much easier!

Next step is to get autoguiding operational, this will be a seven hour event and I really do not want to manually guide for the entire duration. Particularly with a telescope that was setup in the daytime and is not properly polar aligned.

A couple other steps remain in the preparation. Automate the camera to take photos at a regular interval. Insure I can provide a good video feed to the computer sending out the webcast. I do have a few more weeks to accomplish this. I am certain those weeks with speed by surprisingly quickly. Time to get ready!