Cloudy Views Through a Clear Lens: George Observatory Anticipates Research Explosion When Wet Weather Dissipates

It’s been a wet, cloudy year for George Observatory, but flooding and poor viewing nights at Brazos Bend State Park haven’t kept astronomers from dreaming. Big breakthroughs have happened at the George in the past, and with a complete restoration of the 36-inch, deep space Gueymard Research Telescope, a return to astronomical research is quite simply a waiting game. And with even more rainfall this week, astronomers will have to wait a little longer. The park will remain closed until at least July 12.

“We couldn’t do research forever because of the lens,” George Director Peggy Halford said, referring to the heavy deposits of grime the telescope suffered during its 50 years standing in the muggy climates of Louisiana State University and west Texas wetlands. “And as soon as we got the lens restored, the park flooded.”

george2

Photo posted June 3 on Brazos Bend State Park Facebook page. The post reads, “In the history of the park (since 1984), water levels have never been this high.”

 

In spite of this development, both amateur and professional astronomers have been using the past 13 months, April and May 2016 in particular, to prioritize future projects using the refreshed equipment. As water over park roads continues to prevent access to the observatory, and cloud cover access to the night sky, these scientists are keeping their heads in the game through planning and pitching sessions.

george

Photo posted June 2 on Brazos Bend State Park Facebook page. The post reads, “We awoke this morning to find water over Park Road 72 for a roughly 1.25-mile section between Park Headquarters and the Nature Center and a small section between the park entrance and Park Headquarters.”

In an age of computer-guided photometry and NASA probes, the science of star-study from the ground “may not be that glamorous,” Halford offers, but it’s not without significant value. One project idea, for example, involves the study of what happens in space after a supernova goes off, or in science-speak, cataclysmic variable star system follow-up observations.

george3

Artist’s rendition of a cataclysmic variable star. By Mark A. Garlick.

Not all stars are alone; some come in pairs. Cataclysmic variables are double-star systems that include a super-dense white dwarf and a normal star rapidly orbiting each at a rate of about once an hour. Because the white dwarf is so close to its partner, it strips off material from the normal star’s corona, creating an accretion disk around itself as it accumulates more and more mass..As this energy vacuuming proceeds, unstable matter in the accretion disk occasionally ignites, ejecting a flash of light called a nova. Eventually, the white dwarf will absorb enough of its partner’s energy to detonate a super-massive thermonuclear explosion of incredible power — a supernova. The novae and supernovae of cataclysmic variables are recorded in all cases, but few events are studied, according to Halford.

“The big surveys are great at catching these things in outburst, but there’s little value in the discovery if no follow-up is done,” Halford stated. “The follow-up photometry gives us the rate of fade, and an idea of the characteristics of a particular type of variable, or an idea of the angular momentum of accretion disk in a binary system, et cetera.”

In other words, the moments after novae are some of the most crucial in the effort to know more about these systems, and the lives and behavior of stars in general. Science being an empirical pursuit, the more data, the better. The Gueymard is particularly suited to this type of research given its deep-space capabilities as well as its accessibility to Houston local astronomers.

george4

The relative size of all asteroids visited by spacecraft as of November 2010.

For the purists, the observatory offers an opportunity to discover asteroids — large bodies of rock and ice within our solar system — through classic methods. While computerized telescopes can now scan for inter-planetary bodies and minor planets much faster than a human ground observer, the pursuit is no less exciting or valuable when new discoveries are made.

“In years past, we’ve had astronomer teams that have discovered more than 500 asteroids,” Halford said. “We have a few people who are going to continue to do it by hand and by eye. If they did discover one coming toward Earth, it could potentially be life-saving.”

George astronomers have also proposed a project that could track light pollution in the area using the magnitude of stars. With this set of data, they could fight for more governmental regulation of municipal lighting. Halford and other interested volunteers at the George have already won battles in the fight to keep the skies dark.

george5

Photos of the night sky before and during the Aug. 14, 2003 blackout in the northeast U.S. and Canada. In urban areas, the Milky Way and orbiting satellites suddenly became visible without light pollution.

“About 15 years ago when we heard the Grand Parkway was going to be built, with the museum’s support, we talked to the state legislature and got a bill passed that allowed us to talk to county commissioners about light in unincorporated areas,” Halford said. “There is currently a lighting ordinance around the George Observatory.”

As Houston and surrounding cities continue to grow, studies of how light affects the appearance of the night sky will provide continuing support for the astronomy community and preservation in general. From the star-lover’s perspective, the sky is yet another endangered species or threatened environment.

While the water continues to recede, these astronomers will continue to plan. The McDonald Observatory in west Texas is always an option, but that means a 12-hour drive and it’s expensive to get time on the telescopes, according to Halford.

“We can’t get to our telescope, so now’s the time to throw out some ideas,” she said. “For the local astronomer who wants to contribute to the scientific body of knowledge, this is the best place to do it.”

Seeing Stars with James Wooten: Last Chance for Winter Constellations in April

Starmap April

Jupiter is now high in the east-southeast at dusk. It outshines all stars we ever see at night, so you can’t miss it. 

Mercury is visible just after sunset this month. Face west at twilight, and look low in the sky over the point where the sun sets. Mercury isn’t as brilliant as Venus or Jupiter, but it easily outshines the stars near it in the sky, so it’s not too hard to find. 

Mars is in the south-southwest at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition in May. It has now surpassed nearby Saturn in brightness.

Saturn is in the south-southwest at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars remains close to Saturn this month.

Venus is becoming lost in the sun’s glare. Already, it doesn’t rise until deep into morning twilight, and Venus continues to approach the sun all month.

April is the last month to see the set of brilliant winter stars which now fill the western evening sky. Dazzling Orion is in the southwest at dusk. His three-starred belt is halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points rightward to Aldebaran in Taurus the Bull. To Orion’s upper left are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards the left. Forming a triangle with Sirius and Betelgeuse is Procyon, the Little Dog Star. 

Joining the winter stars are stars of spring rising in the east. Look for Leo, the Lion at dusk. Ursa Major, the Great Bear, which includes the Big Dipper, is high above the North Star on spring evenings. Extend the Big Dipper’s handle to ‘Arc to Arcturus’ and then ‘speed on to Spica’. There are fewer bright stars in this direction because of where the plane of our galaxy is in the sky. The area of sky between Gemini and Taurus and over Orion’s head is the galactic anticenter, which means that we face directly away from the galactic center when we look in this direction. Those bright winter stars setting in the west are the stars in our galactic arm, right behind the sun. On the other hand, if you look at the sky between Ursa Major, Leo, Virgo, and Bootes, you’re looking straight up out of the galactic plane, towards the galactic pole. There are fewer stars in this direction.

Moon Phases

Moon Phases in April 2016:

New: April 7, 6:24 a.m.

First Quarter: April 13, 10:59 p.m.

Full: April 22, 12:24 a.m.

Last Quarter: April 29 10:29 p.m.

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. 

Clear Skies!

Seeing Stars with James Wooten: The Stars of Summer are Here

The Summer Triangle is high in the east.  This consists of the brightest stars in Cygnus, Lyra, and Aquila.  Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius to his left.  Leo, the Lion, sets in the west.  From the Big Dipper’s handle, ‘arc to Arcturus’ and ‘speed on to Spica’ in the southwest.  Venus now moves away from Jupiter as they both gradually become lost in the Sun’s glare

The Summer Triangle is high in the east. This consists of the brightest stars in Cygnus, Lyra, and Aquila. Scorpius, the Scorpion, is in the south, with the ‘teapot’ of Sagittarius to his left. Leo, the Lion, sets in the west. From the Big Dipper’s handle, ‘arc to Arcturus’ and ‘speed on to Spica’ in the southwest. Venus now moves away from Jupiter as they both gradually become lost in the Sun’s glare

This is the last month to observe the two brightest planets in the western evening sky. On June 30, Venus overtook Jupiter. This month, watch Venus shift to the left of Jupiter each evening at dusk. Meanwhile, both planets appear lower and lower to the horizon each night, until they are both lost in the Sun’s glare by the end of the month. At dusk, look over the point of sunset for the brightest objects there; Venus and Jupiter outshine everything but the Sun and the Moon.

Saturn is now in the southern sky at dusk. Although it is not as brilliant as Venus or Jupiter, it outshines the stars around it, so it’s also easy to see.

Mars remains lost in the glare of the Sun.

The Big Dipper is above and 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 southwest at dusk. Leo, the Lion, sets in the west at dusk.

Antares, brightest star of Scorpius, the Scorpion, is in the southeast, with the ‘teapot’ of Sagittarius rising behind it. Saturn is right above the scorpion’s head. The Summer Triangle has fully risen in the northeast. The stars of summer are here.

full-moon-2

Moon Phases in July 2015:

Full July 1, 9:20 pm; July 31, 5:43 am
Last Quarter July 8, 3:24 pm
New July 15, 8:24 pm
1st Quarter July 23, 11:04 pm

At 2:41 pm on Monday, July 6, Earth is as far from the Sun as it will get this year, a moment known as aphelion. Remember, though, that the difference between aphelion and perihelion (in January) is small (only about 3%). Earth’s 23.5 degree tilt on its axis is a much more important effect. That’s why we have all this miserable heat and humidity now, rather than in January.

Just before 6:50 am CDT on Tuesday, July 14, the New Horizons spacecraft makes its closest approach to Pluto. As this is our first opportunity ever to gather real data from Pluto and its moons, astronomers are quite excited. The craft is already close enough to take some pictures, which you can see here. The Museum will have special activities for this occasion; email me if you want more information.

The Full Moon of July 31 is the second one of the month. That’s one of the definitions of a Blue Moon.

Planetarium Schedule:

Brazos Bend State Park, where our George Observatory is sited, has been closed since May 27 because the rains of Memorial Day and of Tropical Storm Bill caused the Brazos to overflow. The park plans to reopen on a limited basis July 8, making July 11 the first Saturday available for public observing.

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. I generally do one such tour on short June evenings.

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.

KJR_3611

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.

84820023

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.