Margaret Allen

Research: SMU students discover two new supernovae

SMU graduate student researchers have discovered two new supernovae, and their observations of these massive exploding stars will help improve the astronomical “tape measure” that scientists use to calculate the acceleration of the expansion of the universe.

A supernova discovered Wednesday, Feb. 6, 2013 exploded about 450 million years ago, said Farley Ferrante, a graduate student in the Department of Physics who made the initial observation.

The exploding star is in a relatively empty portion of the sky labeled “anonymous” in the faint constellation Canes Venatici. Home to a handful of galaxies, Canes Venatici is near the constellation Ursa Major, best known for the Big Dipper.

A second supernova discovered Tuesday, Nov. 20, 2012 exploded about 230 million years ago, said Ferrante, who made the initial observation. That exploding star is in one of the many galaxies of the Virgo constellation.

Both supernovae were spotted with the Robotic Optical Transient Search Experiment’s robotic telescope ROTSE3b, which is now operated by SMU graduate students. ROTSE3b is at the McDonald Observatory in the Davis Mountains of West Texas near Fort Davis.

The supernova that exploded about 450 million years ago is officially designated Supernova 2013X. It occurred when life on Earth consisted of creatures in the seas and oceans and along coastlines. Following naming conventions for supernovae, Supernova 2013X was nicknamed “Everest” by Govinda Dhungana, an SMU graduate student who participated in the discovery.

The supernova that exploded about 230 million years ago is officially designated Supernova 2012ha. The light from that explosion has been en route to Earth since the Triassic geologic period, when dinosaurs roamed the planet. “That’s fairly recent as these explosions go,” Ferrante said. Dhungana gave the nickname “Sherpa” to Supernova 2012ha.

Everest and Sherpa are two of about 200 supernovae discovered worldwide in a given year. Before telescopes, supernovae observations were rare — sometimes only several every few centuries, according to the scientists.

“Everest and Sherpa aren’t noteworthy for being the youngest, oldest, closest, furthest or biggest supernovae ever observed,” Ferrante said. “But both, like other supernovae of their kind, are important because they provide us with information for further science.”

Everest and Sherpa are Type 1a supernovae, the result of white dwarf explosions, said Robert Kehoe, physics professor and leader of the astronomy team in the Department of Physics.

The scientists explain that a white dwarf is a dying star that has burned up all its energy. It is about as massive as the Earth’s sun. Its core is about the size of the Earth. The core is dense, however, and one teaspoon of it weighs as much as Mount Everest, Kehoe said.

A white dwarf explodes if fusion restarts by tugging material from a nearby star, according to the scientists. The white dwarf grows to about one and a half times the size of the sun. Unable to support its weight, Kehoe said, collapse is rapid, fusion reignites and the white dwarf explodes. The result is a Type 1a supernova.

“We call these Type 1a supernovae standard candles,” Ferrante said. “Since Type 1a supernovae begin from this standard process, their intrinsic brightness is very similar. So they become a device by which scientists can measure cosmic distance. From Earth, we measure the light intensity of the exploded star. As star distances from Earth increase, their brilliance diminishes.”

While Sherpa is a standard Type 1a, Everest is peculiar. It exhibits the characteristics of a Type 1a called a 1991T, Ferrante said.

“Everest is the result of two white dwarfs that collide, then merge,” he said.

Like other Type 1a supernovae, Everest and Sherpa provide scientists with a tiny piece to the puzzle of one of the greatest mysteries of the universe: What is dark energy?

Every Type 1a supernova provides astronomers with indirect information about dark energy, which makes up 73 percent of the mass-energy in the universe. It’s theorized that dark energy explains the accelerating expansion of our universe at various epochs after the Big Bang.

“Every exploding star observed allows astronomers to more precisely calibrate the increasing speed at which our universe is expanding,” Ferrante said. “The older the explosion, the farther away, the closer it was to the Big Bang and the better it helps us understand dark energy.”

Written by Margaret Allen

> Read more from the SMU Research blog

March 5, 2013|Research|

Research: How hiding in plain sight saved the Jicarilla Apache

Book cover of 'Becoming White Clay' by B. Sunday EiseltNorth America’s Jicarilla Apache tribe cloaked themselves in trade, diplomacy, and intermarriage and nearly escaped incarceration on an American Indian reservation. How they did it has been a mystery of the historical American Southwest – until now.

“In some ways, the Jicarilla still remain invisible,” according to SMU anthropologist Sunday Eiselt.

The Jicarilla Apache, an amalgamation of nomadic tribes that in the 18th century migrated off the plains and settled in the northern Rio Grande of New Mexico, were accustomed to armed resistance, guerrilla tactics and inter-tribal warfare.

They fought alongside the Pueblo Indians in the Revolt of 1680 and later resisted Comanche raiders, sometimes as contract fighters and security guards for the Spanish and American trade caravans. Then quietly, deliberately and peacefully they slipped off the radar of Spanish colonization and U.S. Manifest Destiny until 1888, when the Jicarilla became the last Native American tribe forcibly settled on a reservation.

“This was not an accident of history,” says Eiselt. The Apache, particularly the Jicarilla, were experts at invisibility — not just physically, but also socially and economically. For example, Jicarilla warriors on raids would paint themselves during the journey to the plains with white clay to avoid detection by their enemies.

The protocol beckoned supernatural or spiritual protections to bring the warriors home safely. Just as white clay was a warrior strategy for self-preservation, it stands as a metaphor for the primary message of the book.

“By ‘becoming white clay’ in their social and economic dealings,” Eiselt contends, “the Jicarilla turned the tables on non-Indian expansion and disappeared into the cultural fabric of the Southwest’s Pueblo colonies as other Native Americans were being forced onto reservations.” The Jicarilla, without firing a shot, not only avoided confinement and even extermination for nearly two centuries, they rescued their culture from extinction.

“The Jicarilla essentially colonized the colonies,” says Eiselt, an expert on the Jicarilla. “They became invisible to government authorities because they were always on the move, they intermarried with the Pueblo and Hispanic peoples, and they established long-standing trade with them. They disappeared by becoming essential, an everyday part of the frontier society of New Mexico, which sustained Spanish, Mexican and ultimately U.S. interests.”

Encapsulation of one society within a larger, dominant or more powerful society is a phenomenon known as enclavement. As a strategy it was not new to the ancestors of the Jicarilla. In fact, enclavement may have occurred multiple times as their Athapaskan ancestors migrated from Canada to the American Southwest beginning as early as the 12th century, Eiselt says.

“Few scholars recognize how significant the Jicarilla contribution was to the survival of the traditional cultures of New Mexico,” says Eiselt, whose new book “Becoming White Clay” (University of Utah Press, 2012) is a comprehensive study of one of the longest-lived and most successful nomadic ethnic group enclaves in North America. “There hasn’t been a whole lot of research into the Jicarilla, even though they’ve always been there and their contribution to New Mexican history is almost entirely underappreciated.”

“Sunday Eiselt has produced the definitive work on Jicarilla Apache history and archaeology,” says Ronald H. Towner, University of Arizona. “She uses a strong theoretical approach to enclavement and combines history, archaeology and ethnohistory to not only describe past Jicarilla movements and cultural development throughout the Southwest, but to explain how and why Jicarilla social organization at different scales structured that development during times of warfare, removal from traditional lands and economic stress. Eiselt’s scholarship is second-to-none.”

Written by Margaret Allen

> Read the full story at the SMU Research blog

February 25, 2013|Research|

Research: SMU paleontologist identifies new Texas fossil species

A new species of coelacanth fish has been discovered in Texas. Pieces of tiny fossil skull found in Fort Worth have been identified as 100 million-year-old coelacanth bones, according to SMU paleontologist John Graf.

The coelacanth has one of the longest lineages — 400 million years — of any animal. It is the fish most closely related to vertebrates, including humans.

The SMU specimen is the first coelacanth in Texas from the Cretaceous, said Graf, who identified the fossil. The Cretaceous geologic period extended from 146 million years ago to 66 million years ago.

Graf named the new coelacanth species Reidus hilli. It is now the youngest coelacanth identified in the Lone Star State, a distinction previously belonging to a 200 million-year-old coelacanth from the TriassicReidus hilli is also the first coelacanth ever identified from the Dallas-Fort Worth area.

Coelacanth fossils have been found on every continent except Antarctica. Few have been found in Texas, said Graf, a paleontology graduate student in the Huffington Department of Earth Sciences of SMU’s Dedman College.

The coelacanth has eluded extinction for 400 million years. Scientists estimate it reached its maximum diversity during the Triassic. The fish was thought to have gone extinct about 70 million years ago. However, the fish rose to fame in 1938 after live specimens were caught off the coast of Africa. Today coelacanths can be found swimming in the depths of the Indian Ocean.

“These animals have one of the longest lineages of any vertebrates that we know,” Graf said.

The SMU specimen demonstrates there was greater diversity among coelacanths during the Cretaceous than previously known.

“What makes the coelacanth interesting is that they are literally the closest living fish to all the vertebrates that are living on land,” he said. “They share the most recent common ancestor with all of terrestrial vertebrates.”

Coelacanths have boney support in their fins, which is the predecessor to true limbs. “Boney support in the fins allows a marine vertebrate to lift itself upright off the sea floor,” Graf said, “which would eventually lead to animals being able to come up on land.”

Written by Margaret Allen

> Read the full story at the SMU Research blog

October 31, 2012|Research|

Research: New insight into a 19th-century fossil feud

In the late 1800s, a flurry of fossil speculation across the American West escalated into a high-profile national feud called the Bone Wars. Drawn into the spectacle were two scientists from the Lone Star State: geologist Robert T. Hill, now acclaimed as the Father of Texas Geology, and naturalist Jacob Boll, who made many of the state’s earliest fossil discoveries.

Hill and Boll had supporting roles in the Bone Wars through their work for one of the feud’s antagonists, Edward Drinker Cope, according to a new study by SMU’s Louis Jacobs, a vertebrate paleontologist in the Huffington Department of Earth Sciences, Dedman College.

The study by Jacobs expands knowledge about Cope’s work with Hill and Boll. It also unveils new details about the Bone Wars in Texas that Jacobs deciphered from 13 letters written by Cope to Hill. Jacobs discovered the letters in an archive of Hill’s papers at SMU’s DeGolyer Library. The letters span seven years, from 1887 to 1894.

Hill, who worked for the U.S. Geological Survey, not only provided Cope with fossils of interest but also shared geological information about fossil locales.

Boll, who was a paid collector for Cope — as was the practice at the time — supplied the well-known paleontologist with many fossils from Texas. More than 30 of the taxa ultimately named by Cope were fossils collected by Boll.

“Fossils collected by Boll and studied by Cope have become some of the most significant icons in paleontology,” said Jacobs, president of SMU’s Institute for the Study of Earth and Man. His study, “Jacob Boll, Robert T. Hill, and the Early History of Vertebrate Paleontology in Texas,” is published in the journal Historical Biology as part of the conference volume of the 12th International Symposium on Early Vertebrates/Lower Vertebrates.

Jacobs describes the late 1800s as a period of intense fossil collecting. The Bone Wars were financed and driven by Cope and his archenemy, Othniel Charles Marsh. The two were giants of paleontology whose public feud brought the discovery of dinosaur fossils to the forefront of the American psyche.

Over the course of nearly three decades, however, their competition evolved into a costly, self-destructive, vicious all-out war to see who could outdo the other. Despite their aggressive and sometimes unethical tactics to outwit one another and steal each other’s hired collectors, Cope and Marsh made major contributions to the field of paleontology, Jacobs said.

Written by Margaret Allen

> Read the full story at the SMU Research blog

September 11, 2012|Research|

Research: Do trade restrictions actually increase exporting?

Stock photo of a young woman shopping for electronic devicesImposing trade restrictions on parallel imports has the surprising effect of motivating a firm to export, according to a new study by economists Santanu Roy of SMU’s Dedman College and Kamal Saggi of Vanderbilt University.

Using game theory analysis, the economists found that diverse parallel importing policies among countries today make it possible to analyze for the first time how competition between firms and allowing or banning parallel imports can influence competition in foreign and domestic markets.

“Our research is the first to look at the consequence of strategic policy setting by governments in the context of competition in domestic and foreign markets,” said Roy, professor and director of graduate studies in the Department of Economics.

Most surprising among the findings, he said, is that imposing trade restrictions on parallel imports can actually motivate a firm to export – which can be the case when the market to which the firm is exporting is smaller than its own.

“So even though you are formally prohibiting the import of a product, you are actually promoting trade,” Roy said. “And that’s a new way of looking at this.”

Parallel importing occurs when a manufacturer exports its trademarked or patented products to a foreign market where demand, policies or price pressures require the goods be sold at a lower price. A third-party buyer purchases the low-priced goods and imports them back to the manufacturer’s home country, undercutting domestic prices.

The controversial practice has spawned gray market retail, where consumers buy high-value, brand-named goods at cut prices, such as electronics, video games, alcohol, books and pharmaceuticals.

Some advocates of free trade decry parallel importing, saying it infringes on manufacturers’ intellectual property rights accorded by copyright, patent and trademark laws. That, in turn, can discourage investment in new technology and products.

As a result, some countries allow parallel importing; others ban it. For example, parallel importing is allowed among the member countries of the European Union. It’s not permitted by the United States, although exceptions exist for many different products. Generally speaking, developed nations restrict parallel importing, while developing nations allow it.

The study by Roy and Saggi found there is no one-size-fits-all solution – neither a global ban nor a blanket endorsement. In fact, the authors found that policy diversity is working well because it takes into account important variables such as similarity or dissimilarity of markets, as well as competing products and government regulations.

“The only area where there may be need for intervention is where there may be major asymmetries between countries – where one country is very large and the other is very small,” Roy said.

Roy and Saggi report their findings in two articles: “Equilibrium Parallel Import Policies and International Market Structure,” a scenario in which there are quality differences in the products across countries, forthcoming in the Journal of International Economics; and “Strategic Competition and Optimal Parallel Import Policy,” a scenario in which there is asymmetrical protection of intellectual property, forthcoming in the Canadian Journal of Economics. The two economists were members of a development research group at the World Bank that researched parallel importing.

Written by Margaret Allen

> Read the full story from the SMU Research blog

May 8, 2012|Research|
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