"This planet is a complete mystery," says astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics (CfA). "We don't know how it formed or how it got to where it is today. What we do know is that it's not going to last forever."
"Kepler-78b is going to end up in the star very soon, astronomically speaking," agrees CfA astronomer Dimitar Sasselov.
Not only is Kepler-78b a mystery world, it is the first known Earth-sized planet with an Earth-like density. Kepler-78b is about 20 percent larger than the Earth, with a diameter of 9,200 miles, and weighs almost twice as much. As a result it has a density similar to Earth's, which suggests an Earth-like composition of iron and rock.
The tight orbit of Kepler-78b poses a challenge to theorists. When this planetary system was forming, the young star was larger than it is now. As a result, the current orbit of Kepler-78b would have been inside the swollen star.
"It couldn't have formed in place because you can't form a planet inside a star. It couldn't have formed further out and migrated inward, because it would have migrated all the way into the star. This planet is an enigma," explains Sasselov.
According to Latham, Kepler-78b is a member of a new class of planets recently identified in data from NASA's Kepler spacecraft. These newfound worlds all orbit their stars with periods of less than 12 hours. They're also small, about the size of Earth. Kepler-78b is the first planet in the new class to have its mass measured.
"Kepler-78b is the poster child for this new class of planets," notes Latham.
The team studied Kepler-78b using a newly commissioned, high-precision spectrograph known as HARPS-North, at the Roque de los Muchachos Observatory on La Palma. They coordinated their work with a second, independent team using the HIRES spectrograph at the Keck Observatory. The teams' measurements agreed with each other, increasing their confidence in the result.
Kepler-78b is a doomed world. Gravitational tides will draw it even closer to its star. Eventually it will move so close that the star's gravity will rip the world apart. Theorists predict that Kepler-78b will vanish within three billion years.
Interestingly, our solar system could have held a planet like Kepler-78b. If it had, the planet would have been destroyed long ago leaving no signs for astronomers today.
Kepler-78b orbits a Sun-like G-type star located 400 light-years from Earth in the constellation Cygnus.
Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
For more information, contact:David A. Aguilar
Christine Pulliam | EurekAlert!
First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester
Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology
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....
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....
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...
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...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy