Planetrise

Alien world looms large in its neighbor's sky

2012-06-22

(Press-News.org) Few nighttime sights offer more drama than the full Moon rising over the horizon. Now imagine that instead of the Moon, a gas giant planet spanning three times more sky loomed over the molten landscape of a lava world. This alien vista exists in the newly discovered two-planet system of Kepler-36.

"These two worlds are having close encounters," said Josh Carter, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).

"They are the closest to each other of any planetary system we've found," added co-author Eric Agol of the University of Washington.

Carter, Agol and their colleagues report their discovery in the June 21st Science Express.

They spotted the planets in data from NASA's Kepler satellite, which can detect a planet when it passes in front of, and briefly reduces the light coming from, its parent star.

The newfound system contains two planets circling a subgiant star much like the Sun except several billion years older. The inner world, Kepler-36b, is a rocky planet 1.5 times the size of Earth and weighing 4.5 times as much. It orbits about every 14 days at an average distance of less than 11 million miles.

The outer world, Kepler-36c, is a gaseous planet 3.7 times the size of Earth and weighing 8 times as much. This "hot Neptune" orbits once each 16 days at a distance of 12 million miles.

The two planets experience a conjunction every 97 days on average. At that time, they are separated by less than 5 Earth-Moon distances. Since Kepler-36c is much larger than the Moon, it presents a spectacular view in its neighbor's sky. (Coincidentally, the smaller Kepler-36b would appear about the size of the Moon when viewed from Kepler-36c.) Such close approaches stir up tremendous gravitational tides that squeeze and stretch both planets.

Researchers are struggling to understand how these two very different worlds ended up in such close orbits. Within our solar system, rocky planets reside close to the Sun while the gas giants remain distant.

Although Kepler-36 is the first planetary system found to experience such close encounters, it undoubtedly won't be the last.

"We're wondering how many more like this are out there," said Agol.

"We found this one on a first quick look," added Carter. "We're now combing through the Kepler data to try to locate more."

This result was made possible with asteroseismology. Asteroseismology is the study of stars by observing their natural oscillations. Sunlike stars resonate like musical instruments, due to sound waves trapped in their interiors. And just like a musical instrument, the larger the star, the "deeper" are its resonances. This trapped sound makes the stars gently breathe in and out, or oscillate.

Co-author Bill Chaplin (University of Birmingham, UK) noted, "Kepler-36 shows beautiful oscillations. By measuring the oscillations we were able to measure the size, mass and age of the star to exquisite precision."

He added, "Without asteroseismology, it would not have been possible to place such tight constraints on the properties of the planets."

INFORMATION:

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Protein may be key to psoriasis and wound care

2012-06-22

Psoriasis is an autoimmune disorder in which skin cells proliferate out of control. For some hard-to-heal wounds, the problem is just the opposite: Restorative skin cells don't grow well or fast enough. In a paper published in the June 21, 2012 issue of Immunity, researchers at the University of California, San Diego School of Medicine describe a molecule that may lead to new treatments for both problems. An international team of scientists led by principal investigator Richard L. Gallo, MD, PhD, professor of medicine and chief of UC San Diego's Division of Dermatology, ...

Immune system molecule weaves cobweb-like nanonets to snag Salmonella, other intestinal microbes

2012-06-22

A team of researchers led by UC Davis Health System has found that human alpha-defensin 6 (HD6) – a key component of the body's innate defense system – binds to microbial surfaces and forms "nanonets" that surround, entangle and disable microbes, preventing bacteria from attaching to or invading intestinal cells. The research describes an entirely new mechanism of action for defensins, an important group of molecules known to bolster the defenses of circulating white blood cells, protect cellular borders from invasive pathogens and regulate which "friendly" microbes can ...

Our microbes, ourselves

2012-06-22

Gut bacteria's key role in immunity is tuned to the host species, researchers have found, suggesting that the superabundant microbes lining our digestive tract evolved with us—a tantalizing clue in the mysterious recent spike in human autoimmune disorders. A new study reports that the superabundance of microbial life lining our GI tracts has coevolved with us. These internal bacteria, which are essential for a healthy immune system, are ultimately our evolutionary partners. In other words, humans may have coevolved with gut bacteria unique to humans, which are not immunologically ...

Parents seen as critical stakeholders in expanding newborn screening

2012-06-22

Parents must be considered when states decide to expand genetic screening programs for newborns, according to a new study that looked at mandatory testing panels and political pressure by advocacy groups. Nearly all infants in the United States undergo a heel prick within days of birth for a simple blood test to detect rare genetic disorders. For decades, state-based mandatory newborn screening programs have focused on disorders such as phenylketonuria (PKU) or hypothyroidism in which a prompt diagnosis and treatment could prevent disability or even death. In recent ...

Penn researchers' study of phase change materials could lead to better computer memory

2012-06-22

PHILADELPHIA -- Memory devices for computers require a large collection of components that can switch between two states, which represent the 1's and 0's of binary language. Engineers hope to make next-generation chips with materials that distinguish between these states by physically rearranging their atoms into different phases. Researchers at the University of Pennsylvania have now provided new insight into how this phase change happens, which could help engineers make memory storage devices faster and more efficient. The research was conducted by Ritesh Agarwal, associate ...

Researchers tune the strain in graphene drumheads to create quantum dots

2012-06-22

Tightening or relaxing the tension on a drumhead will change the way the drum sounds. The same goes for drumheads made from graphene, only instead of changing the sound, stretching graphene has a profound effect on the material's electrical properties. Researchers working at the National Institute of Standards and Technology (NIST) and the University of Maryland have shown that subjecting graphene to mechanical strain can mimic the effects of magnetic fields and create a quantum dot, an exotic type of semiconductor with a wide range of potential uses in electronic devices. The ...

Genomics and African queens

2012-06-22

Researchers have started to unveil the genetic heritage of Ethiopian populations, who are among the most diverse in the world, and lie at the gateway from Africa. They found that the genomes of some Ethiopian populations bear striking similarities to those of populations in Israel and Syria, a potential genetic legacy of the Queen of Sheba and her companions. The team detected mixing between some Ethiopians and non-African populations dating to approximately 3,000 years ago. The origin and date of this genomic admixture, along with previous linguistic studies, is consistent ...

Enzyme offers new therapeutic target for cancer drugs

2012-06-22

Researchers at the University of California, San Diego School of Medicine have uncovered a new signal transduction pathway specifically devoted to the regulation of alternative RNA splicing, a process that allows a single gene to produce or code multiple types of protein variants. The discovery, published in the June 27, 2012 issue of Molecular Cell, suggests the new pathway might be a fruitful target for new cancer drugs. Signal transduction in the cell involves kinases and phosphatases, enzymes that transfer or remove phosphates in protein molecules in a cascade or ...

McGill researchers discover the cause of an inherited form of epilepsy

2012-06-22

Researchers at McGill University have discovered the cause of an inherited form of epilepsy. The disease, known as double-cortex syndrome, primarily affects females and arises from mutations on a gene located on the X chromosome. Drs. Susanne Bechstedt and Gary Brouhard of the Department of Biology have used a highly advanced microscope to discover how these mutations cause a malformation of the human brain. The results of their study are published in the journal Developmental Cell. When the brain develops in the uterus, new brain cells are born deep within the brain, ...

Climate drilling in the Arctic Circle

2012-06-22

During the past 2.8 million years extreme warm periods occurred in the Arctic at irregular intervals. Analytical results from the longest sediment core that has ever been drilled in the terrestrial areas of the Arctic have shown temperatures that were previously considered impossible for the Arctic Circle. In addition, a notable correlation of the warm periods in the Arctic with large melting events in Antarctica points to previously unknown interactions between the Polar Regions. These are the findings of an international research team led by Professor Martin Melles of ...

LAST 30 PRESS RELEASES:

Azacitidine–venetoclax combination outperforms standard care in acute myeloid leukemia patients eligible for intensive chemotherapy

Measurable residual disease shows strong potential as an early indicator of survival in patients with acute myeloid leukemia

Chemotherapy and radiation are comparable as pre-transplant conditioning for patients with b-acute lymphoblastic leukemia who have no measurable residual disease