First Light: Gueymard research telescope debut to coincide with Hubble anniversary

April 25 will mark the 25th anniversary of the world-famous Hubble Space Telescope, and the George Observatory will celebrate with a debut of their restored 36-inch Gueymard Research Telescope, the largest specialized Cassegrain telescope open to the public, and the only one that chooses to use an eyepiece.

The Gueymard Research Telescope, a 36-inch Ritchey—Chretien Cassegrain.

The Gueymard Research Telescope, a 36-inch Ritchey—Chretien Cassegrain.

“You can see the images with your own eyes instead of on a computer screen like other telescopes,” George Observatory Director Peggy Halford said. “It gives you a much more personal experience.”

A Ritchey—Chretien design, the telescope features hyperbolic primary and secondary mirrors which sharpen the image, eliminating the fuzzy edges around its center, what is known to astronomers as an off-axis coma. With optics this precise, the telescope brings to the naked eye the phenomena of deep space.

A couple of years ago, astronomers at the George began to notice the quality of images in the Gueymard was degrading. Views were clearer in the smaller, though still research-grade, 11-inch refractor attached to the Gueymard. While they knew something was wrong, they didn’t expect the adventure they would embark upon to restore it to its original power.

Amateur astronomers remove the primary mirror from the Gueymard Research Telescope.

Amateur astronomers remove the primary mirror from the Gueymard Research Telescope.

When they removed the primary mirror, the equivalent of “checking under the hood,” they found environmental pollutants built up in microscopic divots and fissures left on its surface after its original grind 50 years ago. Optical technology has come a long way since then; imperfections in contemporary optics are virtually absent, Halford said. The George acquired the telescope from Louisiana State University, where it had stood in swamp-like conditions another 25 years prior to its installation in Brazos Bend State Park. Time and humidity had taken its toll.

The Museum sent the delicate 500-pound mirror to a coating company that did the simple things first — a bath and a new reflective coating — to try to refurbish the mirror, but the coating refused to stick, and they knew they would need to bring in the big guns.


The wooden container the George employees used to ship the hyperbolic mirror.

It took a three-month fundraising campaign, Save Our Scope, to raise the money to hire Master Optician James Mulherin to resurface the element. Halford is proud to report the campaign took much less time than she anticipated, given the surprising amount of support from the public.

February 2014, the George again sent mirror away, this time to Mulherin, and a year an a month later, the project was complete. Mulherin took a trip to the George to help install the element, and he sat down to explain the particulars of the resurfacing project and what he does at his business, Optical Mechanics, Incorporated.

One of two specialists in the nation who do this kind of work, Mulherin came highly recommended from amateur astronomers who dropped his name to Halford at star parties when they learned of the George’s difficulty with the Gueymard. What was tough for the astronomers was a piece of cake for Mulherin.

“It was a fairly routine job,” said Mulherin, whom universities and aerospace companies regularly hire for their optical needs. “There was no real challenge.”

Mulherin did mention, however, that he had to work around the hole in the middle of the mirror, where a steel hub goes through to hold the mirror in place at the bottom of the telescope. Normally a glass plug is installed during the grinding phase, but there was too much difference in the composition of this 50-year-old glass and that of contemporary optics, he said, so he had to work around it.

Using specialized equipment to move the delicate, but massive, hunk of glass, Mulherin’s company stripped the aluminum finish and ground down the old surface to remove the imperfections in the element. The opticians then re-shaped the mirror’s hyperbolic curvature, shining light through the glass at different stages to check their progress. Finally, Mulherin coated the surface with enhanced aluminum to increase reflectivity.


The George will debut the repaired Gueymard April 25, coinciding with the 25th anniversary of the Hubble Space Telescope.

The result was a total restoration of the optics, but volunteers still had to put the mirror back into place. The replacement, including the removal of the cement blank used to counterbalance the telescope while the mirror was out, along with cleaning the housing, took Tracy Knauss, Dana Lambert and Chris Randall 10 days straight, working from noon to 10 p.m.

Changes to the width of the mirror required volunteers to adjust the secondary mirrors after the installation of the main element — no small task. Installation and adjustments of the precision optics continued from 8 a.m. to 10 p.m. Monday, and again Tuesday from noon to 10 p.m.

“I wanted to stick an eyepiece into it and it work,” Halford said, but collimating the telescope, or aligning the elements with accuracy, required much more time.

Mulherin said he felt at home at the George during the course of the project, and happy to help.

“I feel like I’m part of the community,” he said. “When I started, we were all amateur astronomers, and I found I was more interested in optics than astronomy.”

About the telescope, he said, “It’s amazing to me that it still works.”

Halford hopes for clear skies April 25, but if conditions turn cloudy, she said, “We’ll just show it off.” The George will observe regular Saturday hours from 3 to 10 p.m. for the event.

First Light & 25th Anniversary of the Hubble Space Telescope Celebration
Saturday, April 25
3:00 p.m. – 10:00 p.m.
April 25 will mark the 25th anniversary of the world-famous Hubble Space Telescope, and the George Observatory will celebrate with a debut of their restored 36-inch Gueymard Research Telescope, the largest specialized Cassegrain telescope open to the public, and the only one that chooses to use an eyepiece. 

The stars at night are big and…. falling: Geminid Meteor Shower Returns December 13!

Of the many meteor showers that occur throughout the year, the Geminid Meteor Shower in December may be the most reliably active. This meteor shower occurs when the Earth passes near 3200 Phaethon, a Palladian Asteroid. The Geminids were first observed in 1862. The shower gets its name because they appear to originate in the Gemini constellation. 

Under ideal conditions, one may see as many as 50-100 meteors an hour. The meteors from this shower are also especially bright, and many astronomers believe that the shower is intensifying every year. The shower should peak around 9:00 p.m. on Saturday December 13th. That’s good news because most of the other significant showers, like the Perseids, peak after midnight. With no Moon until after midnight, we should be able to see a lot of meteors (weather permitting of course). 

The George Observatory will be open Saturday, December 13th until midnight for viewing the shower. Tickets for viewing the shower are $5 and include access to our telescopes.  That night, we’ll be able to view several star clusters and nebulae with our scopes. Jupiter should rise in time to be viewed as well. We’ll also have our Discovery Dome available for $3. 

If you can’t make it out to the George, you can still view the shower anywhere with dark skies.



This week @HMNS: Making physics cool and celebrating 25 years at the George

This series is about events happening at the Houston Museum of Natural Science. For more information about HMNS, our exhibits and programming, please visit


FILM SCREENING: Particle Fever 

Imagine being able to watch Franklin received his first jolt of electricity or Edison turn on the first light bulb!

Particle Fever gives you a front row seat to our generation’s most significant and inspiring scientific breakthrough as it happens the launch of the Large Hadron Collider, the biggest and most expensive experiment in the history of the planet. 10,000 scientists from over 100 countries join forces in pursuit of a single goal: to recreate conditions that existed just moments after the Big Bang and find the Higgs boson, potentially explaining the origin of all matter. 

Join Dr. Paul Padley, one of the Rice University professors who worked on the Higgs boson discovery on the Hadron Collider, for this one-night-only event.


MEMBERS EVENT: The George Observatory 25th Anniversary Celebration

Celebrate the George Observatory’s 25th anniversary and peer through the refurbished research telescope to see spectacular views of Saturn along with a variety of deep space objects. Cash bar and light refreshments.



Seeing Stars with James Wooten: Two eclipses for the price of one!

Star Chart - October 2014

This star map shows the Houston sky at 10 pm CDT on September 1, 9 pm CDT on September 15, and dusk on September 30. To use the map, put the direction you are facing at the bottom. The Summer Triangle is high in the west. This consists of the brightest stars in Cygnus, Lyra, and Aquila. The ‘teapot’ of Sagittarius sets in the southwest, with Mars to its right. Pegasus, the Flying Horse, is high in the east. To the south and east, we see a vast dim area of stars known as the Celestial Sea, where only Fomalhaut stands out.

This month, Mars remains in the southwest at dusk this month as it pulls away from Antares in Scorpius. Mars continues to fade a little each night as Earth continues to leave it farther behind

Saturn drops into the Sun’s glare by Halloween. See how long you can keep track of it as it appears lower and lower to the southwest horizon each night this month.

Jupiter is now higher in the east at dawn; it is the brightest thing there. 

Venus is passing behind the Sun and thus out of sight this month. Superior conjunction (Venus in line with the Sun, on the far side of the Sun) is on October 25.

In October the Big Dipper is to the lower left of the North Star at dusk, and soon sets. As a result, it may be hard to see if you have trees or buildings north of you. As the Big Dipper sets, though, Cassiopeia rises. This is a pattern of five stars in a distinct W shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.  

Autumn represents sort of an ‘intermission’ in the sky, with bright summer stars setting at dusk, while bright winter stars such as Orion have not yet risen.  The ‘teapot’ of Sagittarius sets in the southwest early in the evening. The Summer Triangle is high in the west. Meanwhile, the Great Square of Pegasus is in the east, indicating that autumn has begun. The stars rising in the east are much dimmer than those overhead and in the southwest because when you face east at dusk in October, you face out of the Milky Way plane. The center of our Galaxy lies between Scorpius and Sagittarius, while the Summer Triangle is also in the galactic plane. Pegasus, on the other hand, is outside the plane of our galaxy and is a good place to look for other galaxies. Nearby constellations Andromeda and Triangulum (a small triangle) contain the spiral galaxies nearest to our own. 

Total Lunar Eclipse October 8 + Partial Solar Eclipse October 23!
The Full Moon of October 8 enters Earth’s shadow completely, causing a total lunar eclipse!  Partial eclipse begins at 4:15 am, with totality from 5:24 to 6:25 am. The Moon then begins to leave the shadow, but is still partially eclipsed as it sets at 7:26 in Houston. This is the second of four total eclipses we can see in 2014-15; the next one occurs April 4, 2015.

The New Moon of October 23 partially blocks the Sun, causing a partial solar eclipse!  For us, the eclipse begins at 5:00 and is still in progress at sunset (6:43 pm). For both eclipses you’ll need a site with a clear view to the west to watch the setting Moon or Sun in eclipse. 

Moon Phases in October 2014:
First Quarter: October 1, 2:32 pm; October 30, 9:48 pm
Full: October 8, 5:50 am
Last Quarter: October 15, 2:12 pm
New: October 23, 4:55 pm 

Celebrate The George October 10-12!
The George Observatory celebrates its 25th anniversary the weekend of October 10-12!  That weekend, the observatory is open for a members event on Friday evening and Sunday night in addition to our customary Saturday night hours

Click here for the Burke Baker Planetarium Schedule.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer.  If you’re there, listen for my announcement.