Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers take close-up pictures of mysterious dark object

09.04.2010
For the first time, astronomers have directly observed the mysterious dark companion in a binary star system that has puzzled skywatchers since the 19th century.

Using an instrument developed at the University of Michigan, scientists have taken close-up pictures of Epsilon Aurigae during its eclipse, which happens every 27 years. "Close up" in this case is a relative term, but the images zoom in enough to show the shape of the dark object's shadow.

"Seeing is believing," said John Monnier, an associate professor in the U-M Department of Astronomy who is an author of a paper about the research findings published in the April 8 edition of Nature. Researchers from the University of Denver and Georgia State University were involved as well.

Epsilon Aurigae is the fifth brightest star in the northern constellation Auriga. For more than 175 years, astronomers have known it is dimmer than it should be, given its mass. They also noticed its brightness dip for more than a year every few decades. They surmised that it was a binary system in which one companion was invisible. But what type of object was the companion?

Because astronomers hadn't observed much light from it, the prevailing theory labeled it a smaller star orbited edge-on by a thick disk of dust. The theory held that the disk's orbit must be in precisely the same plane as the dark object's orbit around the brighter star, and all of this had to be occurring in the same plane as Earth's vantage point. This would be an unlikely alignment, but it explained observations.

The new images show that this is indeed the case. A geometrically thin, dark, dense, but partially translucent cloud can be seen passing in front of Epsilon Aurigae.

"This really shows that the basic paradigm was right, despite the slim probability," Monnier said. "It kind of blows my mind that we could capture this. There's no other system like this known. On top of that, it seems to be in a rare phase of stellar life. And it happens to be so close to us. It's extremely fortuitous."

The disk appears much flatter than recent modeling from the Spitzer Space Telescope suggests, Monnier said.

"It's really flat as a pancake," he said.

Monnier led the creation of the Michigan Infra-Red Combiner (MIRC) instrument that was used to produce these images. MIRC uses a process called "interferometry" to combine the light entering four telescopes at the CHARA array at Georgia State University and amplify it so that it seems to be coming through a device 100 times larger than the Hubble Space Telescope.

MIRC allowed astronomers to see the shape and surface characteristics of stars for the first time. Previously, stars were mere points of light even with the largest telescopes.

"Interferometry has made high resolution imaging of distant objects a reality," said Fabien Baron, a post-doctoral researcher in the Department of Astronomy who helped with the imaging in this study. "It most probably will solve many mysteries but also raise many new questions."

The paper is called "Infrared images of the transiting disk in the epsilon Aurigae System." Xiao Che, a graduate student in the U-M Department of Astronomy, contributed to the research. The lead authors are astrophysics graduate student Brian Kloppenborg and astronomy professor Bob Stencel at the University of Denver.

This research is funded by the National Science Foundation and the office of the dean of the College of Arts and Sciences at Georgia State University.

John Monnier: www.astro.lsa.umich.edu/~monnier

Nicole Casal Moore | EurekAlert!
Further information:
http://www.umich.edu

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of 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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>