A University of Toronto-led team of astronomers has discovered over two dozen new free-floating brown dwarfs, including a lightweight youngster only about six times heftier than Jupiter, that reside in two young star clusters. What's more, one cluster contains a surprising surplus of them, harbouring half as many of these astronomical oddballs as normal stars.
"Our findings suggest once again that objects not much bigger than Jupiter could form the same way as stars do. In other words, nature appears to have more than one trick up its sleeve for producing planetary mass objects," says Professor Ray Jayawardhana, Canada Research Chair in Observational Astrophysics at the University of Toronto and leader of the international team that made the discovery.
Brown dwarfs straddle the boundary between stars and planets. Sometimes described as failed stars, they glow brightly when young, from the heat of formation, but cool down over time and end up with atmospheres that exhibit planet-like characteristics. Scientists think that most brown dwarfs may have formed like stars, in isolation from contracting gas clouds, but some of the puniest free-floaters may have formed like planets around a star and later ejected.
The findings come from observations using the Subaru Telescope in Hawaii and the Very Large Telescope (VLT) in Chile during the Substellar Objects in Nearby Young Clusters (SONYC) survey. Astronomers took extremely deep images of the NGC 1333 and rho Ophiuchi star clusters with Subaru at both optical and infrared wavelengths. Once they identified candidate brown dwarfs from the very red colors, the research team confirmed them with spectra taken at Subaru and the VLT. The team's findings will be reported in two upcoming papers in the Astrophysical Journal and presented this week at a scientific conference in Garching, Germany.
The six-Jupiter-mass brown dwarf found in the NGC 1333 cluster is one of the least massive free-floating objects known. "Its mass is comparable to those of giant planets, yet it doesn't circle a star. How it formed is a mystery," said Aleks Scholz of the Dublin Institute of Advanced Studies in Ireland, lead author of one paper and a former postdoctoral fellow at the University of Toronto.
Several other newly identified brown dwarfs in both NGC 1333 and rho Ophiuchi clusters have masses below 20 times that of Jupiter.
"Brown dwarfs seem to be more common in NGC 1333 than in other young star clusters. That difference may be hinting at how different environmental conditions affect their formation," says University of Toronto’s Koraljka Muzic, lead author of the second paper.
"We could not have made these exciting discoveries if not for the remarkable capabilities of Subaru and the VLT. Instruments that can image large patches of the sky and take hundreds of spectra at once are key to our success," said co-author Motohide Tamura of the National Astronomical Observatory of Japan.
Other co-authors of the two papers are Vincent Geers of ETH Zurich in Switzerland, also a former UofT postdoc, and Mariangela Bonavita of the University of Toronto.
Note to media: Visit www.artsci.utoronto.ca/main/media-releases/brown-dwarfs-from-sonyc-survey for images and research papers associate with this media release.
MEDIA CONTACTS:Ray Jayawardhana
Sean Bettam | EurekAlert!
Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas
22.09.2017 | Forschungszentrum MATHEON ECMath
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy