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 DGIST develops 20 times faster biosensor
24.04.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of 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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>