Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Keeping an Eye on the Universe

16.01.2012
Astronomers from the California Institute of Technology and the University of Arizona have released the largest data set ever collected that documents the brightening and dimming of stars and other celestial objects ­ 200 million in total.

The University of Arizona's Catalina Sky Survey keeps a watchful eye on asteroids that might cross the Earth's path. A byproduct of that effort is the largest database compiling the brightnesses of 200 million objects in the universe, including supernovae and stars torn up by super-massive black holes.

The night sky is filled with objects such as asteroids that dash across the sky and others ­ such as exploding stars and variable stars ­ that flash, dim, and brighten. Studying such phenomena can help astronomers better understand the evolution of stars, massive black holes in the centers of galaxies, and the structure of the Milky Way.

These types of objects also were essential for the recent discovery of dark energy ­ the mysterious energy that dominates the expansion of the universe ­ that earned last year's Nobel Prize.

Using images obtained by the UA's asteroid-hunting Catalina Sky Survey, the Catalina Real-Time Transient Survey, or CRTS, lets CalTech astronomers systematically scan the heavens for these dynamic objects, resulting in an unprecedented data set that will allow scientists worldwide to pursue new research.

"Exploring variable objects and transient phenomena like stellar explosions is one of the most vibrant and growing research areas in astrophysics," said S. George Djorgovski, professor of astronomy at Caltech and principal investigator on the CRTS. "In many cases, this yields unique information needed to understand these objects."

The new data set is based on observations taken with the 0.7-meter telescope on Mt. Bigelow in Arizona. The observations were part of the Catalina Sky Survey, a search for Near-Earth Objects, or NEOs ­ asteroids that may pose a threat to Earth ­ conducted by astronomers at the UA.

By repeatedly taking pictures of large swaths of the sky and comparing these images to previous ones, the CRTS is able to monitor the brightness of about half-billion objects, allowing it to search for those that dramatically brighten or dim. In this way, the CRTS team identified tens of thousands of variables, maximizing the science that can be gleaned from the original data.

The new data set contains the so-called brightness histories of a total of
200 million stars and other objects, incorporating more than 20 billion independent measurements.

"This set of objects is an order of magnitude larger than the largest previously available data sets of their kind," said Andrew Drake, a staff scientist at Caltech and lead author on a poster presented at the meeting of the American Astronomical Society in Austin on Jan. 12.

"It will enable many interesting studies by the entire astronomical community."

One of the unique features of the survey, Drake said, is that it emphasizes an open-data philosophy. "We discover transient events and publish them electronically in real time, so that anyone can follow them and make additional discoveries."

"It is a good example of scientific-data sharing and reuse," Djorgovski added. "We hope to set an example of how data-intensive science should be done in the 21st century."

The data set includes more than 1,000 exploding stars called supernovae, including many unusual and novel types, as well as hundreds of so-called cataclysmic variables, pairs of stars in which one spills matter onto another, called a white dwarf; tens of thousands of other variable stars; and dwarf novae, which are binary stars that dramatically change in brightness.

"We take hundreds of images every night from each of our telescopes as we search for hazardous asteroids," said Edward Beshore, principal investigator of the UA's asteroid-hunting CSS. "As far back as 2005, we were asking if these data could be useful to the community of astronomers.

We are delighted that we could forge this partnership. In my estimation, it has been a great success and is a superb example of finding ways to get greater value from taxpayers' investments in basic science."

The team said it soon plans to release additional data taken with a 1.5-meter telescope on Mt. Lemmon in Arizona and a 0.5-meter telescope in Siding Spring in Australia.

In addition to Djorgovski, Drake and Beshore, the team includes staff scientist Ashish Mahabal, computational scientist Matthew Graham, postdoctoral scholar Ciro Donalek and research scientist Roy Williams from Caltech.

Researchers from other institutions include Steve Larson, Andrea Boattini, Alex Gibbs, Al Grauer, Rik Hill and Richard Kowalski from the UA; Mauricio Catelan from Universidad Catholica in Chile; Eric Christensen from the Gemini Observatory in Hawaii; and Jose Prieto from Princeton University.

The Caltech research is supported by the National Science Foundation. The work done at the UA is supported by NASA.

LINKS:
Catalina Sky Survey: http://www.lpl.arizona.edu/css
Catalina Real-Time Transient Survey: http://crts.caltech.edu
CONTACTS:
Edward Beshore
Lunar and Planetary Laboratory and Steward Observatory The University of Arizona
520-621-4900
ebeshore@lpl.arizona.edu
Deborah Williams-Hedges
California Institute of Technology
debwms@caltech.edu
626-395-3227
Daniel Stolte
University Communications
The University of Arizona
520-626-4402
stolte@email.arizona.edu

Daniel Stolte | University of Arizona
Further information:
http://www.arizona.edu

More articles from Earth Sciences:

nachricht Climate Change in West Africa
17.06.2019 | Julius-Maximilians-Universität Würzburg

nachricht Determining the Earth’s gravity field more accurately than ever before
13.06.2019 | Technische Universität Graz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

A new force for optical tweezers awakens

19.06.2019 | Physics and Astronomy

New AI system manages road infrastructure via Google Street View

19.06.2019 | Information Technology

A new manufacturing process for aluminum alloys

19.06.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>