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.

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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.

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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. 

Seeing Stars with James Wooten: August 2013

Venus remains in the west at dusk. It outshines everything but the Sun and Moon, so you can begin observing it during deep twilight. As August ends, Venus begins to approach Saturn.

Saturn is now shining in the south/southwest at dusk. Although not as bright as Venus, it does outshine the stars around it, so you can’t miss it. Jupiter is higher in the morning sky this month. Look for it in the east at dawn.

Mars, much dimmer than Jupiter, now pulls away from it in the morning sky. Look for it to Jupiter’s lower left in the morning sky at dawn.

Seeing Stars with James Wooten

The Big Dipper is to the left of the North Star, with its handle pointing up. From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are in the south at dusk.  Leo, the Lion, sets in the west at dusk.

Antares, brightest star of Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius to its left. The Summer Triangle is high in the east. The stars of summer are here. Meanwhile, the Great Square of Pegasus begins to rise in the east, indicating that fall is near.

Moon Phases in August 2013:

New                                August 8, 2:15 am
1st Quarter                    August 15, 10:19 pm
Full                                 August 22, 1:15 pm
Last Quarter                 August 29, 12:44pm

The Perseid meteor shower peaks on Monday morning, August 12, as it does every year in mid-August. As always, we see more meteors in the pre-dawn hours, because that’s when Earth rotates us into the meteor stream. The Perseids have a broad peak, meaning that quite a few meteors are visible for a few days before and after the best date.

Thus, you’ll still see quite a few meteors if you come to George Observatory on Saturday night, August 10 and stay into Sunday morning, August 11. We’ll be open until 2 am, long enough for the shower to get good. Keep in mind that this is a meteor shower with, on average, one meteor per minute, and not a meteor storm, which would average about one meteor per second.

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.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.

Don’t miss the Geminid Meteor Shower this Friday night! Here’s how, where and when to view

The annual Geminid Meteor Shower peaks this weekend, and we’ve got some tips for stargazers hoping to catch it.

The New Moon falls on Thursday, Dec. 13 this year, which should guarantee us nice, dark night for viewing. The Geminid Meteor shower peaks every December and is one of the best, most reliable showers, producing an average of 100 meteors per hour.

A Geminid meteor in 2009, as viewed from San Francisco
A Geminid meteor in 2009, as viewed from San Francisco, courtesy of Wikimedia Commons

Says HMNS Astronomer James Wooten: “The Geminids are unique among meteor showers because they are associated not with a comet but with an asteroid, 3200 Phaethon. This means that with Geminids, we see significant activity much earlier in the night than with other showers.”

That means instead of having to wait until the wee morning hours to see this beautiful shower, meteors will start radiating from the constellation Gemini as early as 9 or 10 p.m., although the shower will likely peak just before dawn.

As with all showers, the Geminid Meteor Shower will be best viewed away from city light pollution. The George Observatory will be open Friday night and into Saturday morning for observation. For directions to The George, located just an hour south of Houston, click here. Entry to Brazos Bend State Park is $7 per person; free for kids under 12. You don’t need any special equipment for viewing, just a chair, blankets and maybe some hot apple cider.

If you observe the meteor shower and are able to capture some great photos, share them with our Flickr group or by using the hashtag #hmnsgeminid on Twitter and Instagram. If Facebook’s your thing, post your photos on our wall, or tag us, and we’ll compile a credited album of everyone’s shots!

Seeing Stars with James Wooten: December 2012

Mars remains an evening object. It is low in the southwest at dusk.

Jupiter is now up all night long. Opposition — when Earth is directly between Jupiter and the Sun and Jupiter literally rises at sundown and sets at sunup — is Dec. 3. After that date, Jupiter only gets higher and more prominent in the evening sky. Face east/northeast at dusk and look for the brightest thing there (unless the Moon is also there), as Jupiter outshines all stars we see at night.

Sky Map November 2012

Venus remains in the east at dawn, continuing a spectacular morning apparition. It now appears a little closer to the horizon each morning.

Saturn is a little higher in the morning sky this month; look for it just above the much brighter Venus. Mercury is visible for the first half of the month at dawn.  Look just under Venus.

The autumn ‘intermission’ — when few bright stars are out at dusk — is over; brilliant winter stars enter the evening skies of December. Watch dazzling Orion rise as twilight ends. He rises with his three-starred belt almost vertical, halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points up to Aldebaran in Taurus, the Bull. This winter, the Bull also contains Jupiter.

Rising with Orion and far to his left are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins.  By 8 p.m. in mid-month, the two Dog Stars have joined Orion. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards the horizon.

Moon Phases in December 2012:
Last Quarter                  December 6, 9:32 a.m.
New                               December 13, 2:41 a.m.
1st Quarter                    December 19, 11:19 p.m.
Full                                December 28, 4:22 a.m.

At 5:12 p.m. on Friday, Dec. 21, the Sun is directly overhead at the Tropic of Capricorn, the farthest point south at which it can be overhead. This puts the Sun as low as possible in our daytime sky, and as high as possible in the sky for anyone in the Southern Hemisphere. This also makes daytime as short as possible for us, and as long as possible for folks “down under.” Accordingly, this moment is the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere.

The Geminid Meteor Shower peaks this month, as it does every December. Along with the Perseids in August, the Geminids are one of the two most reliable meteor showers, producing on average about 100 meteors per hour. The Geminids are unique among meteor showers because they are associated not with a comet but with an asteroid, 3200 Phaethon. This means that with Geminids, we see significant activity much earlier in the night than with other showers.

Most meteor showers peak in the hours immediately before dawn. This is because what plows through the debris field is the leading edge of the Earth, and that’s the side going from night into day. Since Phaethon is an asteroid, however, debris along its orbital path forms a shallower angle to Earth’s orbital path, meaning that we begin to face into the debris field as early as 9 or 10 p.m. Meteors will seem to ‘radiate’ from the constellation Gemini, hence the name of the shower. However, they may appear anywhere in the sky.

As always, you see more meteors the farther you are from big city lights, which hide dimmer ones. Our George Observatory will be open Friday night, Dec. 14, into Saturday morning, Dec. 15, for observing this meteor shower.

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.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.

Would you like email updates on current events in the sky, at the planetarium, and at the George Observatory?  If so, send an email to astroinfo@hmns.org.