GSU Mt. Wilson CHARA Telescope Array

CHARA Array

The photograph above is of telescope “E1” of Georgia State University’s six telescope CHARA optical/infrared interferometric array on Mt. Wilson. The long tubes extending from the telescope enclosure are vacuum light tubes. These carry light from each of the six one meter telescopes to a facility where the beams are processed and combined. The photograph is from a recent run on the Mt. Wilson Rim Trail.

Other things being equal, a telescope’s ability to discern detail is determined by its aperture. In a conventional telescope the aperture is the width of the main optical element. The majority of telescopes used by amateurs have apertures well under 0.5 m. Larger professional optical telescopes can range from a couple of meters up to about 10 m. The Hooker telescope on Mt. Wilson has an aperture of 2.5 m and the 200″ Hale telescope on Mt. Palomar about twice that. Hubble’s primary mirror has a diameter of 2.4 meters.

The benefit of a telescope array is that when the light from two telescopes is combined, the combined instrument’s ability to discern detail — its resolving power — is nearly the same as a telescope with an aperture equal to the distance between the telescopes. This distance is termed a baseline. The Y-shaped CHARA Array has 15 baseline configurations ranging from 31 to 331 meters.

The CHARA Array’s large effective aperture, the successful application of leading edge optical technologies, and exceptionally steady atmosphere over Mt. Wilson have produced a number of astronomical imaging “firsts,” including an image of the surface of a main sequence star (Altair) and images of an interacting binary star system with a suggestion of mass transfer between the pair.

The Altair imagery above is from a University of Michigan News Release that accompanied the publication of the paper “Imaging the Surface of Altair” by Monnier et al., 2007, Science.



The image above is from a remarkable animation of a sequence of images of the interacting binary star system Beta Lyrae. (Zhao et al. ApJ 684, L95)

For more information see the Georgia State University CHARA Array web site.

Why Won’t My Smart Key Work?

Antenna farm on Mt. Wilson

The gate to Skyline Park on Mt. Wilson doesn’t normally open until 10:00 a.m., so for Saturday’s run we parked in a large turnout along the loop road downhill from the gate. A trailhead that accesses the Kenyon Devore Trail is just downhill from the turnout, and a few yards down the trail is the lateral trail to Skyline Park. The Rim Trail trailhead is in Skyline Park along the service road that leads to the observatory grounds. This Observatory Pamphlet (PDF) includes a map that shows its location.

So we’re about to start the run, and I’m going through the routine of last minute checks. Everything looks good so I lock the car and — nothing happens. Where’s the familiar single beep? I try again… Nothing.

Ah technology! It doesn’t take long to figure out that those giant transmitters towering above me are jamming my smart key. OK, I want to get running, but I also want to be sure I’m going to able to start the car when we get back. Fortunately, the key system has an emergency mechanical key to get in the car, and then there’s a procedure to enable the car to detect the smart key. The procedure works, and after (mechanically) locking the car we’re off and running.

The pattern of RF energy emitted near an antenna is complex and I imagine it is particularly so in the middle a large antenna farm such as on Mt. Wilson.

I’ve parked in Skyline Park several times without having a smart key problem; however a few years ago I did have a problem with a GPS watch getting a lock on satellites at the start of a Mt. Disappointment race. That hasn’t happended with my current Garmin watch, which has much better satellite acquisition and sensitivity.

I guess whatever lobe of RF was interfering with the key changed shape or position, because when we got back to the car at the end of the run the smart key worked fine!

Mt. Wilson Rim Trail – Kenyon Devore Trail Loop

Big cone Douglas-fir on the Rim Trail near Mt. Wilson

Brett was down for Father’s Day weekend and one of the things we wanted to do was get in a couple of good trail runs. He’s heard me talk (a lot) about the Mt. Disappointment 50K and how it ends. Basically you run 27 hilly miles with over 3600′ of elevation gain, THEN finish the race by doing a 5 mile, 2650′ climb from West Fork up the Gabrielino & Kenyon Devore Trails to the top of Mt. Wilson.

This final climb tells the 50K tale. If you’ve trained well and run a good race a middle-of-the-pack runner might gain 15-20 minutes on this leg. If not, you could easily lose an hour or more. In any case you put everything you have left into this climb. An elevation profile and some stats for Kenyon Devore are included in the post Hitting the (Big) Hills of Southern California.

There are several ways to incorporate Kenyon Devore into a loop, but I could only think of two that didn’t involve running on Mt. Wilson Road. One option was a 22 mile/5000’gain loop from Shortcut Saddle to Mt. Wilson and back. That wasn’t going to happen because just five days before I’d run the Holcomb Valley 33 Mile race. Instead we opted to start on top of Mt. Wilson and use the Rim Trail, Gabrielino Trail and Rincon – Red Box Road to get to West Fork. This would pare down the loop to a manageable 12 miles and 3000′ of gain.



Other than a “few” gnats, a lot of poison oak and some Turricula (Poodle-dog bush), the Rim Trail was in good shape and the running excellent. Once away from the observatory complex the trail has an adventurous, backcounty feel. The trail was in good enough condition that Brett enjoyed running it in the KomodoSport LS.

The day was going to be a scorcher and I was glad that much of the Rim Trail was on the shaded, north side of the crest. The Gabrielino Trail and Rincon – Red Box Road were also relatively cool and in the shade. With no race clock ticking away, we stopped at West Fork and ate some blueberries and PB&J. So far the route had been down, down, down; but in a few minutes it was going to go up, up, up.



One of the surprises of the day was how much the Turricula (Poodle-dog bush) had grown along the Gabrielino and lower Kenyon Devore Trails since I had been here in early March. A rain gauge near here (Opids Camp) recorded nearly seven inches of precipitation from March 25 to April 26. This appears to have promoted the growth of the Turricula. In a very dry rain season the rain and snow had been much needed. It rejuvenated the streams and vegetation, and the area looked much as it would if the seasonal rainfall had been normal.

The Turricula could not be avoided in some places, but that will be remedied in a couple of weeks when Gary Hilliard’s Mt. Disappointment Endurance Run volunteer trailwork group works on this section of the Gabrielino Trail and the Kenyon Devore Trail.

Update June 21, 2012. Although my contact with Turricula on this run was very limited, I did have a mild reaction, mainly on my arms. There was very slight inflammation and the “prickly” itching that is characteristic of Turricula. The itching became noticeable about a day after exposure and persisted for 4-5 days. Although mild, the reaction was stronger than occurred following several similar encounters last year. One difference was the exposure to poison oak on the Rim Trail earlier in the run. It’s possible that there was a cross reaction. This was observed in animal testing, but not in (limited) human tests. However, my reaction following this latest encounter was much, much milder than my first bout of Turricula, which resulted from wading through large patches of the young Poodle-dog plants on miles of overgrown trail. That first very strong response may have also involved a cross reaction with poison oak.



With the Summer Solstice approaching and the Sun so high, the temperature difference between sunny and shaded sections of trail was remarkable. About the time we were on Kenyon Devore the Clear Creek RAWS recorded a fuel temperature — the temperature of a wood dowel in direct sun — at a scorching 104°F. Brett did well on the climb and could have zoomed ahead. I had not recovered from Holcomb and struggled a bit on the exposed and steep sections of trail. Higher on the trail there was a breeze and more shade and that helped. It also helped pouring water over my head at the creek crossing!

It was great to show Brett Kenyon Devore, and what better way to sharpen the appetite for one of his superbly prepared dinners!



Humboldt Lily



Turricula (Poodle-dog Bush)



California Sister

Holcomb Valley 33 Mile Trail Run 2012

Holcomb Valley 33 Mile Trail Run

When a race changes organizers sometimes you’re just not sure what you’re going to get. No worries! It seemed Tom Spiegel and Team Big Bear made every effort to maintain the quality and character of an event that for 15 years was superbly organized by Gary & Pam Kalina.

Although the temperature recorded at Fawnskin was several degrees warmer than last year the temperature on the course was cooler. Jorge Pacheco took advantage of the nearly ideal conditions and flew through the 33 mile course in a record time of 4:11:19!

Of the 118 runners that started the 33 mile this year 93 finished. Half the runners ran faster than the median time of 7:21:32 and half slower. The times for the middle third of the runners ranged from about 6:50 to 8:00.

Here’s an interactive Google Earth flyover of the Holcomb Valley 33 Mile Run that can be viewed in most browsers. (Google Earth plugin required.) Distances specified are based on my GPS traces from the past three years, and were calculated in SportTracks. Distances and placemark locations should be considered approximate. Here’s an elevation profile of the course.

Only the event director and core group of volunteers really know how much work goes into putting on an event. There are innumerable tasks that have to be coordinated and completed, and myriad (usually) minor problems that have to be resolved. The works starts months in advance of the event, and may not end for weeks after the event. The reward is in the smiles of the participants and knowing you have done the best job possible. Thank you Pam & Gary Kalina for organizing the Holcomb Valley Trail Runs for so many years.

Some related posts: Holcomb Valley 33 Mile Trail Run 2011, Holcomb Valley 33 Mile Trail Run 2010

Following are a few photos from this year’s run.



Cougar Crest View



Road Running



Horse Ranch



Leaving Aid #2



Talus on the PCT



Belleville

Southern Pacific Rattlesnake

Southern Pacific Rattlesnake (Crotalus oreganus helleri)

A Southern Pacific Rattlesnake (Crotalus oreganus helleri) at Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

The problem with rattlesnakes is that they can be notoriously difficult to see — especially when they are lurking in the shade on a narrow section of brushy trail and you’re wearing sunglasses.

Related post: Big Southern Pacific Rattlesnake at Ahmanson Ranch

Astronomical Trail Running

With a solar eclipse, lunar eclipse and transit of Venus all occurring over a 17 day period, my trail running has taken on a definite astronomical bent.



Low clouds prevented local viewing of the lunar eclipse, but the May 20 solar eclipse was fantastic. And as a result of a series of interpretive programs offered by Santa Monica Mountains Conservancy and Mountains Recreation & Conservation Authority, I was able to view the transit of Venus this afternoon, while doing one of my regular trail runs in Upper Las Virgenes Canyon Open Space Preserve (aka Ahmanson Ranch).

Local astronomer & volunteer naturalist Pat McQuaid setup his 11″ Celestron telescope on one of the Park’s hilltops, a short distance from the trailhead. With proper filtration and a wide field eyepiece, the image of the planet’s disk crossing the Sun’s face was spectacular! The image seen through his telescope was similar to this NASA – Johnston Space Center photo from the ISS.

The weather was perfect for an afternoon walk (or run), and many people made the half-mile trek.

The transit of Venus across the Sun’s face is a rare event, occurring only a couple times a century. So thank you SMMC, MRCA and naturalist Pat for the opportunity see it in the middle of a trail run!