Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astonomers discover Jupiter-Saturn-like planet in distant solar system

15.02.2008
The simultaneous discovery of two exoplanets slightly smaller than Jupiter and Saturn by an international team of astronomers that includes University of Notre Dame research associate professor of astrophysics David Bennett gives astrophysicists an important clue that solar systems like ours might be quite common.

The report, to be published in the Feb. 15 issue of the journal Science, describes the series of observations that began March 28, 2006, when a collaboration known as Optical Gravitational Microlensing Equipment (OGLE) detected a signal, possibly due to a planet in microlensing event OGLE-2006-BLG-109, that the researchers had discovered and announced two days earlier.

After the OGLE group announced this possible detection of a planetary system via e-mail, other astronomers from the Microlensing Follow-Up Network (MicroFUN), Microlensing Observations in Astrophysics (MOA) and Probing Lensing Anomalies NETwork (PLANET) collaborations also began intensive, round-the-clock observations of this event. The combined data from these four groups revealed a series of brightness variations over the ensuing 11 days that indicated that two planets orbit a star half the mass of the sun located 5,000 light years from Earth. This star, called OGLE-2006-BLG-109L, and its planets were discovered using a technique known as gravitational microlensing.

Early calculations by the report’s lead author, Scott Gaudi of Ohio State University, and the MicroFUN group indicated that most of the telltale brightness variations were due to a planet with a mass similar to that of Saturn, but that there was a brief additional brightening observed from Israel and Chile that could only be explained by an additional planet with nearly the mass of Jupiter. However, Gaudi’s calculations did not provide a perfect fit to the data and involved several approximations.

Subsequently, Bennett performed more sophisticated calculations in his office at Notre Dame using his own advanced computer program that included an important additional feature: the orbital motion of the Saturn-mass planet.

“Even though we observed the micolensing effect of the Saturn for less than 0.3 percent of its orbit, the observations simply could not be explained without accounting for the orbit,” Bennett said.

Critical assistance with these calculations was provided by Sergei Nikolaev at Lawrence Livermore National Laboratory, who devoted much supercomputer time to the calculations.

The result was one of the most complicated calculations of a star-planet system using the gravitational microlensing method.

Gravitational microlensing takes advantage of the fact that light is bent as the rays pass close to a massive object, like a star. The gravity from the mass of the intervening object, or lens star, warps surrounding space and acts like a giant magnifying glass. As predicted by Albert Einstein and later confirmed, this phenomena causes an apparent brightening of the light from the background “source” star. The effect is seen only if the astronomer’s telescope lies in almost perfect alignment with the source star and the lens star. Astronomers are then able to detect planets orbiting the lens star if the light from the background star also is warped by the planets.

The discovery of the double planet system was a triumph for astronomers who use this method, which is of such high sensitivity that it can detect planets similar to those in our own solar system, with the exception of Mercury.

“These planets could not have been detected without any other technique,” Bennett said.

“The light curve of this event revealed an unprecedented amount of information about the planetary host star and the planets,” he continued.

The effect of the orbital motion of the Earth can be detected in the light curve, and this reveals that the mass of the host star is half the mass of the sun. This mass estimate was confirmed by subsequent observations of the planetary host star with the Keck telescope.

The light curve also reveals the orbital motion of the Saturn-mass planet during the 11 days when the planetary signal was visible.

To date, only 25 multiple planet systems have been observed. A majority are very dissimilar to our solar system and that of OGLE-2006-BLG-109L.

The Jupiter- and Saturn-sized planets orbiting OGLE-2006-BLG-109L are only the fifth and sixth planets that have been detected using the gravitational lensing method. Gaudi and Bennett conclude that if the OGLE-2006-BLG-109L planetary system is typical, then it is possible that they would have similar planets as our own solar system.

William Gilroy | EurekAlert!
Further information:
http://www.nd.edu

More articles from Physics and Astronomy:

nachricht Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

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...

Im Focus: Successful Mechanical Testing of Nanowires

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>