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 ).
Laird Close, University of Arizona, Department of Astronomy, email@example.com
Daniel Stolte, University of Arizona Office of Communications, (520) 626-4402; firstname.lastname@example.orgLINKS:
Midwife and signpost for photons
11.12.2017 | Julius-Maximilians-Universität Würzburg
New research identifies how 3-D printed metals can be both strong and ductile
11.12.2017 | University of Birmingham
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Information Technology
11.12.2017 | Power and Electrical Engineering
11.12.2017 | Event News