Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brown Dwarf Found Orbiting a Young Sun-Like Star

30.07.2010
The discovery is expected to shed light on the early stages of solar system formation.

Astronomers have directly imaged a very young brown dwarf (or failed star) in a tight orbit around a young nearby Sun-like star. An international team led by University of Hawaii astronomers Beth Biller and Michael Liu with help from University of Arizona astronomer Laird Close with UA graduate students Eric Nielsen, Jared Males and Andy Skemer made the rare find using the Near-Infrared Coronagraphic Imager (NICI) on the international 8 meter Gemini-South Telescope in Chile.

What makes this discovery special is the proximity between the 36 Jupiter-mass brown dwarf companion (dubbed "PZ Tel B") and its primary star named PZ Tel A. Both are separated by only 18 Astronomical Units (AU), similar to the distance between Uranus to our Sun. Most young brown dwarf and planetary companions found by direct imaging are at orbital separations greater than 50 AU -- larger than the orbit of Pluto (40 AU). In addition to its small current separation, in just the past year, the researchers observed PZ Tel B moving quickly outward from its parent star.

An older image, taken seven years ago and reanalyzed by Laird Close, a professor at UA’s Steward Observatory/department of astronomy, showed PZ Tel B was completely obscured by the glare from its parent star as recently as 2003, indicating its orbit is more elliptical than circular.

“Because PZ Tel A is a rare star being both close and very young, it had been imaged several times in the past” said Laird Close. “So we were quite surprised to see a new companion around what was thought to be a single star.”

Lead author and UA graduate Beth Biller said: "PZ Tel B travels on a particularly eccentric orbit -- in the last 10 years, we have literally watched it careen through its inner solar system. This can best be explained by a highly eccentric, or oval-shaped, orbit.”

The host star, PZ Tel A, is a younger version of the Sun, having a similar mass but a very young age of only 12 million years (about 400 times younger than our Sun). In fact, the PZ Tel system is young enough to still possess significant amounts of cold circumstellar dust, which may have been sculpted by the gravitational interaction with the young brown dwarf companion.

This makes the PZ Tel system an important laboratory for studying the early stages of solar system formation. With an estimated mass of 36 times that of Jupiter, PZ Tel B's orbital motion has significant implications for what type of planets can form (and whether planets can form at all) in the PZ Tel system.

Because PZ Tel B is so close to its parent star, special techniques are necessary to distinguish the faint light of the companion from the light of the primary star. PZ Tel B is separated by about 0.33 arcseconds from PZ Tel A, equivalent to a dime seen at a distance of 7 miles (11 km). In order to take pictures so close to the star, the team used an adaptive optics system coupled to a coronagraph in order to block out excess starlight, and then applied specialized analysis techniques to the images to detect PZ Tel B and measure its orbital motion.

PZ Tel B was discovered using Near-Infrared Coronagraphic Imager (NICI), the most powerful high-contrast instrument designed for imaging brown dwarfs and extrasolar planets around other stars. NICI can detect companions 1 million times fainter than the host star at just 1 arcsecond separations. An international team of researchers drawn from across the Gemini Telescope community is currently carrying out a 300-star survey with NICI, the largest high contrast imaging survey conducted to date.

NICI Campaign leader Michael Liu says: "We are just beginning to glean the many configurations of solar systems around stars like the Sun. The unique capabilities of NICI provide us with a powerful tool for studying their constituents using direct imaging.”

This research was supported by grants from the National Science Foundation and NASA. NICI is a facility instrument at the Gemini Telescope http://www.gemini.edu/sciops/?q=sciops ).

CONTACTS:

Laird Close, University of Arizona, Department of Astronomy, lclose@as.arizona.edu

Daniel Stolte, University of Arizona Office of Communications, (520) 626-4402; stolte@email.arizona.edu

LINKS:
Research paper in
Astrophysical Journal Letters: http://arxiv.org/abs/1007.4808

Daniel Stolte | University of Arizona
Further information:
http://www.gemini.edu/sciops/?q=sciops
http://www.arizona.edu
http://uanews.org/node/33014

More articles from Physics and Astronomy:

nachricht Major discovery in controlling quantum states of single atoms
20.02.2018 | Institute for Basic Science

nachricht Observing and controlling ultrafast processes with attosecond resolution
20.02.2018 | Technische Universität München

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: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

'Lipid asymmetry' plays key role in activating immune cells

20.02.2018 | Life Sciences

MRI technique differentiates benign breast lesions from malignancies

20.02.2018 | Medical Engineering

Major discovery in controlling quantum states of single atoms

20.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>