Widely spaced telescopes also determined asteroid pair's shapes
When the double asteroid Patroclus-Menoetius passed directly in front of a star on the night of Oct. 20, a team of volunteer astronomers across the U.S. was waiting.
Observing the event, known as an occultation, from multiple sites where each observer recorded the precise time the star was obscured, yielded the first accurate determination of the two objects' size and shape. The analysis was led by Dr. Marc W. Buie, staff scientist in Southwest Research Institute's (SwRI) Space Studies Department in Boulder, Colo.
The team effort was a pilot program of the Research and Education Collaborative Occultation Network (RECON), whose recently announced expansion was made possible through a $1 million National Science Foundation grant.
Managed jointly by SwRI and Cal Poly (California Polytechnic State University), RECON supplies telescopes to schools and citizen scientists in rural western states from north-central Washington to southwest Arizona for occultation observations. With the grant, RECON membership will grow from 13 pilot communities to 40.
The October collaborative observations involved volunteers distributed east-west across the United States. Observers were from the International Occultation Timing Association (IOTA) as well as a subset of RECON's observer team. Eleven of 36 observation sites were able to record the occultation. Seven of those were analyzed to estimate an outline, or an elliptical limb fit, of Patroclus of 125 kilometers (km) by 98 km. Six of the observations were combined for Menoetius and yielded a size of 117 km by 93 km.
"Previous estimates of the shape of the asteroid pair had indicated essentially spherical objects," Buie said. "Our new observations indicate a significantly more non-spherical shape, and that shape is identical for the two bodies."
Based on this occultation data combined with previous data, both objects possess axial ratios of 1.3:1.21:1, which indicates a mostly oblate shape, or one that appears flattened at the poles and slightly bulged at the equator.
"The very similar shapes of the pair suggest that they were both spinning much faster when they formed," Buie said. "The current system is in a doubly synchronous state, much like Pluto and Charon, where they orbit each other in the same time it takes for them to rotate."
This asteroid pair orbits the Sun in the Jupiter Trojan cloud of asteroids at 5 AU, or Astronomical Units, from the Sun. (One AU equals the distance from the Sun to Earth). "It shows striking similarities to objects from the more distant Kuiper Belt, suggesting that perhaps this object was relocated inward at some time in the early history of the solar system," Buie said.
Joe Fohn | EurekAlert!
New manifestation of magnetic monopoles discovered
08.12.2017 | Institute of Science and Technology Austria
NASA's SuperTIGER balloon flies again to study heavy cosmic particles
07.12.2017 | NASA/Goddard Space Flight Center
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...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology