Hubble found only two brown dwarfs as companions to normal stars. This means the so-called "brown dwarf desert" (the absence of brown dwarfs around solar-type stars) extends to the smallest stars in the universe.
Sergio Dieterich of Georgia State University in Atlanta and team leader of the study is reporting the results today at the 213th meeting of the American Astronomical Society (AAS) in Long Beach, Calif.
"We still did not find brown dwarfs around small red stars whose mass is only slightly above the hydrogen burning limit. Especially when we consider the fact that brown dwarfs binaries do exist, the fact that there are very few binaries whose components lie on different sides of the hydrogen burning limit is significant," says Dieterich.
The 233 stars surveyed are part of the RECONS (Research Consortium on Nearby Stars) survey meant to understand the nature of the sun's nearest stellar neighbors, both individually and as a population. The current primary goals are to discover and characterize "missing" members of the sample of stars within 32.6 light-years (10 parsecs) of Earth.
RECONS searches for nearby stars through analyzing existing all-sky surveys, combined with observations by a variety of telescopes in both hemispheres. A total of 12 brown dwarfs are currently known within 32.6 light-years of Earth, as compared to 239 red dwarf stars (stars that are largely 20 percent the mass of our sun and are roughly half its diameter and temperature).
In fact, the number of known brown dwarfs is close to that of known extrasolar planets. However, the number of exoplanets known in this region so far is very likely only a lower limit as smaller mass exoplanets are not within our capability of detection at present.
These results are complementary to another study also being reported at the AAS meeting by Micaela Stumpf of the Max Planck Institute for Astronomy in Heidelberg, Germany. The results imply that brown dwarfs tend to hang out with their own kind.
Nearly ten years' worth of NICMOS observations, combined with recent ground-based adaptive optics results, have provided a first estimate of the orbit of the double brown dwarf system Kelu-1 AB. The eccentric orbit is tilted nearly edge-on to Earth and the dwarfs complete an orbit every 38 years.
Based on the orbital dynamics, the total mass of the system is estimated to be 184 Jupiter masses. But, based on spectroscopic and photometric measurements, the two brown dwarfs are no larger than 61 and 50 Jupiter masses, respectively (a star is no smaller than 75 Jupiter masses). Stumpf is reporting that there may in fact be a third member of the system to account for the "missing mass." This would make it potentially the first ever confirmed triple brown dwarf system.
All-sky surveys planned for the next decade, with advanced telescopes like the Large Synoptic Survey Telescope, promise to ultimately solve the puzzle of the "brown dwarf desert" by doing deep infrared searches for the underlying brown dwarf population.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA) and is managed by NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Md. The Space Telescope Science Institute (STScI) conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington, D.C.
STScI is an International Year of Astronomy 2009 (IYA 2009) program partner.
One-way roads for spin currents
23.05.2018 | Singapore University of Technology and Design
Tunable diamond string may hold key to quantum memory
23.05.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy