Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shooting for the Stars

08.06.2011
Lindsay Lohan, Charlie Sheen? Oh, no. “Burned-out star” has a totally different meaning for Judi Provencal.

The University of Delaware astronomer has been busy manning the command center for a star watch of epic proportions, the latest observing run of the Whole Earth Telescope (WET). This global collaboration of observatories collects asteroseismic data—information on stellar waves that pass through hot stars in the cosmos like earthquakes pass through Earth—to determine what’s going on inside these exploding balls of hydrogen and helium gas.

Every day for the past six weeks, Provencal has encouraged faithful observers at 15 major telescopes in 11 countries, from Brazil to China, to focus their lenses on a handful of white dwarfs. These stars have used up all the fuel at their core and while they are still very hot, they are actually slowly cooling, a process that will take billions to trillions of years. Eventually, that’s what will happen to the sun, Provencal says.

The team’s primary target, GD358, is a white dwarf 120 light years away from Earth. Provencal has been studying it since she completed graduate school in 1994; her thesis adviser actually discovered the star.

“This star has changed a lot even since we started watching it several weeks ago,” notes Provencal, an assistant professor of physics and astronomy who directs the Delaware Asteroseismic Research Center (DARC). “It’s pulsating, or sloshing around, at new frequencies. Think of a pulsating star as a bell. If you have a bell and ring it, it makes a certain tone, but now suddenly it has a different tone. Well, what accounts for that? This is a challenge for the theorists.”

An astronomical relay team

Each participating observatory photographs the target star every 20 seconds throughout the night. As sunrise nears, the task is handed off to the next observatory where night has fallen, and so on. All of the images—hundreds of gigabytes of data—are transmitted daily to a computer in Provencal’s UD office.

The data is then transferred over the Internet to Mt. Cuba Astronomical Observatory in Greenville, Del., where it is reduced using software written by UD doctoral student James Dalessio. The observatory and the Crystal Trust are supporting the research.

“From all these images, we’ll pull out how many photons of light are coming from the star in a plot called a light curve,” Provencal says. The light curves are posted on the DARC website every day so the observers can see the data as the run proceeds.

“The star gets brighter and dimmer every 10 minutes because it is pulsating,” she explains. “The peaks in the light curve represent when the star is pulsating outward. From these data, we can determine the frequency of the pulsations, and theoretical physicists like my colleague Mike Montgomery at the University of Texas at Austin can tell us what is happening inside the star.”

After all of the number crunching and analysis, the research team will report their findings in a scientific paper. Generally, it is ready for publication about a year after an observing run, Provencal says.

One question Provencal hopes to answer is whether or not GD358 has a magnetic cycle, meaning that a magnetic field will tug on one side of the star and cause a shift in its rotation every so many years.

“We don’t understand why the sun has a magnetic field, although only a weak one,” she notes. “We’re trying to confirm that this star is similar to what the sun will become in about 4 billion years.”

One of WET’s secondary targets, a star called KIC10139564, more than 300 light years away (the equivalent of more than a quadrillion miles), also is being watched by NASA’s Kepler satellite. Yet no one has compared the satellite’s timings to see how good its clock is, Provencal says. The WET team’s data will help with the evaluation.

When WET started in 1980, having as many as eight telescopes on a run was an achievement, but under Provencal, more than double that number now participate. Her enthusiasm is infectious.

“We’re all interested in the science and get along really well,” she notes. “It’s also just plain fun.”

The team’s good humor and dedication continually impress Provencal.

She points out that a student from Poland with an injured foot is manning a telescope in Croatia, and that the robotic telescope at Mt. Lemmon in Arizona is being remotely operated by scientists in South Korea. And there’s still snow at Russia’s Peak Terskol Observatory at an elevation of 10,000 feet in the Caucasus Mountains. Aleksandr Sergeev, the observer there, has two cats to keep him company.

“He says the cats ‘sweep away the clouds,’” Provencal says, grinning.

When Provencal needs to clear her mind in the midst of such a long observing run, she goes horseback riding. Are her horses named “Star” or perhaps “Comet”?

“No,” Provencal says, “but I do have a cat named ‘Sparkles.’”

Tracey Bryant | Newswise Science News
Further information:
http://www.udel.edu

Further reports about: DARC Delaware Earth's magnetic field Observatory Provencal WET magnetic field white dwarf

More articles from Physics and Astronomy:

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>