Major changes in store at Goldendale Observatory

Big changes are in store at the Goldendale Observatory in Goldendale, Washington. The facility’s telescope, installed in 1973, has already been reconfigured and more improvements are planned. Most of the existing facility, save for the south dome that houses the telescope, will be demolished this winter and replaced with a bigger, more useful observatory that operators hope will be operational in time for the solar eclipse in August.

Troy Carpenter

Troy Carpenter, interpretive specialist at Goldendale Observatory State Park, spoke at a recent Rose City Astronomers meeting about plans for improvements at the observatory. Photo: Greg Scheiderer.

Troy Carpenter, interpretive specialist at the observatory, talked about the plans at the recent meeting of the Rose City Astronomers in Portland. He said that up until recently the telescope and facility had been virtually unchanged since they opened.

The telescope, originally a 24.5-inch classical Cassegrain built by amateur astronomers from Vancouver, Washington, was reconfigured this summer.

“It is still the same telescope, but it has become a Newtonian,” Carpenter said. “The primary reason this was converted from Cassegrain to Newtonian is because, frankly, a classical Cassegrain telescope is totally inappropriate in Goldendale, Washington.”

The original scope, with an effective focal ratio of f/14.5, had a focal length of more than 9,000 millimeters. For telescopes and cameras, that’s extremely long.

“I would even say excessively long because it means the telescope can only operate at very high orders of magnification,” Carpenter said. That was bad, because the telescope couldn’t really look at large, dim objects like the Andromeda galaxy or Orion nebula. Also the scope required good seeing conditions, and while it’s dark and clear in Goldendale, the seeing at the observatory isn’t typically great. On top of that, the secondary mirror was eight inches wide with a ten-inch baffle that blocked too much light, leading to poor contrast at the eyepiece.

“In short, what we had was a horribly over-magnified image with terrible contrast all the time, and as a result this very impressive-looking telescope became kind of infamous, and not so much famous, for being awful,” Carpenter said. “All of these issues contributed to the decision to convert it to a Newtonian.”

That work, and some other adjustments to the telescope, its mount, and adjustability, were completed in September. Back to a more appropriate 3,050-millimeter focal length, Carpenter said views through the telescope are much better now. An improvement yet to come is replacement of the primary mirror, which has deteriorated over 43 years of use. In addition, the mirror is five inches thick, weighs 200 pounds, and takes four hours to reach thermal equilibrium, which is essential to good viewing.

A replacement is being fashioned by a company in Pennsylvania that has done work for NASA. The new mirror, computer designed and fabricated from inexpensive materials, will be the same width but just two inches thick and will weigh only 35 pounds. It will take just 15 minutes to cool to ambient temperature. They hope to have it in Goldendale and installed within the next few months. Its price tag, with a generous educational discount, is $25,000, and while that may sound like a lot, Carpenter noted a similar-sized mirror made of fused quartz might go for ten times as much, a quarter million.

New observatory

Big changes are in store for the buildings at Goldendale Observatory State Park, too.

Observatory plans

Preliminary plans for the new facility at Goldendale Observatory.

“We’re tearing it down so that a much larger facility can be built in its place,” Carpenter said. Everything except the south dome that houses the telescope will go. The new facility will include a large auditorium for classes and lectures that will seat about 150, interpretive exhibit space, and a rooftop observation deck. The total cost of the improvements, which are being made in several phases, is $5 million, which is being covered by capital funds appropriated by the Washington State Legislature. Demolition is set for this winter and they hope to be operational with the new facility in time for the total solar eclipse on August 21, 2017. While Goldendale won’t be within the path of totality as it was for the 1979 eclipse, the Sun will be about 98 percent obscured at the observatory that day, so it will still be something to look at.

One page detailing the planned improvements is above; you can see more of them in the latest newsletter from Friends of Goldendale Observatory.

Light pollution

While it’s pretty dark in Goldendale, many feel that light pollution has increased in town in recent years. Concerned folks this summer held a Gorge Night Sky Symposium to discuss the situation. (See our recap of the event.) Carpenter raised a few eyebrows in the room, mine included, with his take on the issue.

Goldendale Observatory

Goldendale Observatory. Everything but the dome on the right will be demolished to make way for improved facilities. Photo: Greg Scheiderer.

“I’m going to surprise you by not being the loudest opponent of the light pollution we have in Goldendale,” he said. He added that he grew up in New York and has lived in Philadelphia, so he knows light pollution.

“I’ve been to places where stars don’t exist,” he said. So while Goldendale has some light pollution, Carpenter noted that they still have great views of lots of faint fuzzies in the dark night sky.

“It’s low on my priority list because it’s a politically charged issue and it makes us very unpopular every time we bring it up,” Carpenter explained. “Our friends group, however, does care very much about light pollution and they do work hard.”

He noted that the town of Goldendale is working on an improved lighting code, and is converting to full cut-off, dimmable LED street light fixtures. Despite some light pollution, Carpenter said it’s still a great place for stargazing.

“You can see the Milky Way from horizon to horizon in Goldendale,” he said, “and that’s a wonderful thing.”

We look forward to a dark, clear future at Goldendale Observatory.

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2 thoughts on “Major changes in store at Goldendale Observatory

  1. David Ingram

    Thanks for your recap Greg, I was also at the November RCA meeting.
    Troy Carpenter, Goldendale Observatory State Park (GOSP) Intrepretive Specialist, spoke to the RCA membership for 30 minutes about his telescope redesign project. He also spent ten minutes showing two architect drawings of the state of Washington plans to dramatically upgrade the GOSP facility.
    He certainly communicated well when the subject was hardware and facility related.
    He did not take any time to credit GOSP with being the state of Washington’s one and only International Dark-Sky Association “Dark Sky Park”(IDSP). Allow me to remind your readers that GOSP was awarded IDSP status in 2010 thanks to efforts of the prior GOSP Interpretive Specialist, Steve Stout. Troy voluntarily mentioned some of Steve’s advocacy dark sky efforts, but in a disparaging reference to “Don Quixote”.
    I remember Steve as a strong, and unapologetic advocate for protecting the skies over GOSP. For more than 25 years Steve was an exemplary steward of GOSP’s precious dark skies, natural resources over the entire Columbia River basin for tens of thousands of visitors. As great interpretive specialists at every other US and state park have been trained, Steve faithfully educated the visiting public about “his” park’s natural resource treasures. He informed visitors about the personal importance of protecting their collective treasures and he always suggested positive, realistic steps caring citizens could take to rescue and preserve those natural resource treasures for future generations.
    In contrast to Steve, Troy stated that he would not advocate for measures that would protect GOSP night skies from light pollution because that was too politically charged.
    Troy has clearly interpreted his job with the Park as managing his technology project and the park upgrade. but does not seem to have the heart or will to acknowledge the historical dark sky stewardship of Goldendale Observatory State Park, locally and nationally as an IDA Dark Sky Park. In fact he seems clearly willing to step away from that heritage.
    David W. Ingram, Chapter Leader, Dark Skies Northwest. International Dark-sky Association
    http://www.ingramdw@hotmail.com

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