Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Invisible world discovered

09.09.2011
Usually, running five minutes late is a bad thing since you might lose your dinner reservation or miss out on tickets to the latest show. But when a planet runs five minutes late, astronomers get excited because it suggests that another world is nearby.

NASA's Kepler spacecraft has spotted a planet that alternately runs late and early in its orbit because a second, "invisible" world is tugging on it. This is the first definite detection of a previously unknown planet using this method. No other technique could have found the unseen companion.

"This invisible planet makes itself known by its influence on the planet we can see," said astronomer Sarah Ballard of the Harvard-Smithsonian Center for Astrophysics (CfA). Ballard is lead author on the study, which has been accepted for publication in The Astrophysical Journal.

"It's like having someone play a prank on you by ringing your doorbell and running away. You know someone was there, even if you don't see them when you get outside," she added.

Both the seen and unseen worlds orbit the Sun-like star Kepler-19, which is located 650 light-years from Earth in the constellation Lyra. The 12th-magnitude star is well placed for viewing by backyard telescopes on September evenings.

Kepler locates planets by looking for a star that dims slightly as a planet transits the star, passing across the star's face from our point of view. Transits give one crucial piece of information - the planet's physical size. The greater the dip in light, the larger the planet relative to its star. However, the planet and star must line up exactly for us to see a transit.

The first planet, Kepler-19b, transits its star every 9 days and 7 hours. It orbits the star at a distance of 8.4 million miles, where it is heated to a temperature of about 900 degrees Fahrenheit. Kepler-19b has a diameter of 18,000 miles, making it slightly more than twice the size of Earth. It may resemble a "mini-Neptune," however its mass and composition remain unknown.

If Kepler-19b were alone, each transit would follow the next like clockwork. Instead, the transits come up to five minutes early or five minutes late. Such transit timing variations show that another world's gravity is pulling on Kepler-19b, alternately speeding it up or slowing it down.

Historically, the planet Neptune was discovered similarly. Astronomers tracking Uranus noticed that its orbit didn't match predictions. They realized that a more distant planet might be nudging Uranus and calculated the expected location of the unseen world. Telescopes soon observed Neptune near its predicted position.

"This method holds great promise for finding planets that can't be found otherwise," stated Harvard astronomer and co-author David Charbonneau.

So far, astronomers don't know anything about the invisible world Kepler-19c, other than that it exists. It weighs too little to gravitationally tug the star enough for them to measure its mass. And Kepler hasn't detected it transiting the star, suggesting that its orbit is tilted relative to Kepler-19b.

"Kepler-19c has multiple personalities consistent with our data. For instance, it could be a rocky planet on a circular 5-day orbit, or a gas-giant planet on an oblong 100-day orbit," said co-author Daniel Fabrycky of the University of California, Santa Cruz (UCSC).

The Kepler spacecraft will continue to monitor Kepler-19 throughout its mission. Those additional data will help nail down the orbit of Kepler-19c. Future ground-based instruments like HARPS-North will attempt to measure the mass of Kepler-19c. Only then will we have a clue to the nature of this invisible world.

Christine Pulliam | EurekAlert!
Further information:
http://www.harvard.edu

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>