Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Much faster than a speeding bullet, planets and stars escape the Milky Way

30.03.2012
Idan Ginsburg, a graduate student in Dartmouth's Department of Physics and Astronomy, studies some of the fastest moving objects in the cosmos.

When stars and their orbiting plants wander too close to the supermassive black hole at the center of the Milky Way, their encounter with the black hole's gravitational force can either capture them or eject them from the galaxy, like a slingshot, at millions of miles per hour.

Although their origin remains a mystery and although they are invisible, black holes found at galaxy centers make their presence known through the effects they have on their celestial surroundings. The Milky Way's black hole, a monster with a mass four million times that of the Sun, feeds on some of its neighbors and thrusts others out into the intergalactic void.

It's the expelled objects that "become hypervelocity planets and stars," say Ginsburg. "What we learn from these high-speed travelers has significance for our understanding of planetary formation and evolution near the central black hole."

Ginsburg, along with his doctoral adviser Professor Gary Wegner, and Harvard Professor Abraham Loeb are publishing a paper in the Monthly Notices of the Royal Astronomical Society. It describes how the team constructed computer simulations of these hypervelocity bodies as a means to understanding the dynamics involved. "The paper is a 'call to arms' for other astronomers to join the search," Ginsburg announces.

Born in Israel, Ginsburg came to the United States as a child and grew up as a Midwesterner. After high school in Lawrence, Kan., graduating from the University of Illinois at Urbana-Champaign, and studies at Harvard, Ginsburg came to Dartmouth almost five years ago.

For the origin of hypervelocity bodies, Ginsburg and his colleagues point to the close interaction of a binary star system—two stars orbiting a common center—with a massive black hole. The likely scenario is the black hole draws one of the pair into its gravitational well while simultaneously ejecting the other at 1.5 million miles per hour. More than 20 of these hypervelocity stars have been identified in the Milky Way.

"You can also have a lone hypervelocity planet, peeled away from its star and ejected from the black hole. The same mechanism that produces a hypervelocity star produces a hypervelocity planet," Ginsburg explains. "But because it is so small and traveling up to 30 million miles per hour, it cannot be seen. That doesn't mean they won't eventually be found, but currently it is beyond the limitations of our technology."

Ginsburg contends, however, that you could see a hypervelocity star ejected with planets still in tow. In this case, you might be able to see the planets as they cross in front of the star like an eclipse, appearing as a dip in its light curve. While the paper discusses the lone hypervelocity planets, it also draws attention to the planets rotating around the hypervelocity stars.

"That is something that we can detect now," Ginsburg says, "which I think makes it very interesting. … As of yet nobody has looked for these planets transiting hypervelocity stars. We are telling people in this paper that you should look for these."

Joseph Blumberg | EurekAlert!
Further information:
http://www.dartmouth.edu

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and 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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>