Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Disks encircling hypergiant stars may spawn planets in inhospitable environment

10.02.2006


RIT astronomer uses NASA’s Spitzer Space Telescope to study massive stars


This illustration compares the size of a gargantuan star and its surrounding dusty disk (top) to that of our solar system.



The discovery of dusty disks--the building blocks of planets--around two of the most massive stars known suggests that planets might form and survive in surprisingly hostile environments.

The discovery was made through NASA’s Spitzer Space Telescope observations of two hypergiant stars in the Large Magellanic Cloud--the Milky Way’s nearest neighboring galaxy--by a team led by Joel Kastner, a professor at Rochester Institute of Technology’s Chester F. Carlson Center for Imaging Science. His team’s findings will appear in the Feb. 10 issue of Astrophysical Journal Letters.


So far, searches for planets outside the solar system have been restricted to sun-like stars. All of these stars are older, dimmer and cooler objects than hypergiants, which are extraordinarily large and luminous but shorter-lived by billions of years.

Kastner and his team used infrared spectra obtained by Spitzer to study a population of dying stars. They added a new direction to their project when Spitzer’s infrared spectrograph revealed unexpected information. Spitzer’s sensitive spectrometer, which breaks down infrared radiation into component wavelengths as a prism splits visible light into a rainbow, indicated that a third of the stars in the population thought to be in decline--including two massive and exceedingly luminous hypergiants--were actually younger stars in varying stages of development.

The curious spectra of these two hypergiants (R126 and R66)--with one star being 70 times bigger than the sun--led Kastner to reexamine the stars’ classifications as dying. The shape of the spectra, or the amount of light from different wavelengths, is characteristic of flattened disks of dust orbiting the stars.

The two stars’ similar spectra differ in detail, with one encircled by dust in crystalline form, the other by more shapeless, amorphous dust grains. This expands the range of known conditions under which complex dust grains and molecules can form and persist around stars, Kastner says.

Kastner describes the complex mixture of dust detected around the stars as the "tip of the iceberg," probably signaling that the disks of debris surrounding the stars are similar to the solar system’s Kuiper Belt, a vast, distant collection of comet- and even Pluto-like objects. "To explain the very strong infrared radiation we detected, the stars we observed would have to host especially large Kuiper belts," he says.

He adds: "If Kuiper belts are the smoking guns of planetary formation around stars, it seems that these stars, as massive as they are, may be forming planets."

Hypergiants are only a few million years old and have a relatively short lifespan as far as stars go, considering the billions of years it will take the sun to expire.

"These planetary systems, if they do form and exist, are short lived because these massive stars explode as supernovae," Kastner says. "So it’s amazing that the raw material for planets could be found in such a hostile environment."

Kastner’s study highlights only two of more than a dozen or so known examples of very massive stars in the Large Magellanic Cloud that are bright infrared sources. The next phase of the study will use new Spitzer spectra of the additional hypergiant stars to determine how many more are encircled by dusty disks and why only some of these disks contain crystalline dust grains.

"We’ve discovered a new class of object, and we need to use Spitzer to measure the infrared spectra of a lot more of these objects to learn how unique they really are," Kastner says.

Kastner’s team includes Catherine Buchanan from RIT and B. Sargent and W.J. Forrest from the University of Rochester.

Susan Gawlowicz | EurekAlert!
Further information:
http://www.rit.edu

More articles from Physics and Astronomy:

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

nachricht Unraveling the nature of 'whistlers' from space in the lab
15.08.2018 | American Institute of Physics

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Quantum material is promising 'ion conductor' for research, new technologies

17.08.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>