Irandaily | No. 4417 | Science

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New Insights Into Birth Of Giant Planets

Astronomers studying a newborn star have caught a detailed glimpse of planets forming around it, revealing a never-before seen stage of planetary evolution.
Large gas giant planets appear to be clearing a gap in the disk of material surrounding the star, and using gravity to channel material across the gap to the interior, helping the star to grow, Nature said.
Theoretical simulations have predicted such bridges between outer and inner portions of disks surrounding stars, but none have been directly observed until now.
An international team of astronomers have used the partially completed Atacama Large Millimeter/submillimeter Array (ALMA) to study a young star about 450 light-years from Earth. They identified two thin filaments of gas streaming from the outer disk to the inner, across a broad gap cut by young planets.
“Currently, the only mechanism known to produce such gap-crossing dense molecular flows, with residual carbon monoxide gas more diffusely spread out inside the gap, is planetary formation,” lead scientist Simon Casassus of the University of Chile told SPACE.com in an email.
Far from Earth, the fledgling star HD 142527 is nearing the end of its formation process. Around 2 million years old, the young star is about twice as massive as the sun, though it is still slowly growing. A disk of spinning dust and gas left over from its formation surrounds the star, and from this material, planets are being created.
As baby planets, or planetesimals, travel through the disk, they absorb the material around them, creating gaps. Such paths have been seen in a number of newborn systems. HD 142527 boasts a gap that starts at a point equivalent to Saturn’s position in the solar system and extends outward 14 times as far. The gap, which scientists had previously measured, is so large that several planets would be required to clear it of debris.
Using ALMA to observe the system, Casassus and his team have found that the gap is not completely empty. Two filaments reach from the outer disk to the inner, indicating that at least two young planets exist within the space.
The gravity of the planets draws material from the outer ring inward. But while some of the gas and dust falls into orbit around the young gas giants, a fraction of it overshoots the planetesimals, traveling instead to the inner disk. Eventually, the star absorbs the material.

Iranian Man Grows Hair On Eyeball

A 19-year-old Iranian man could see an unusually hairy problem.
A rare cyst on his right eyeball sprouted hairs--impairing his vision and causing him discomfort every time he blinked, Daily Mail reported.
The hairy eyeball was the result of a limbal dermoid--skin tissue that can sprout hair, cartilage, sweat glands and even teeth.
Doctors had to surgically remove the tumor--which measured 5mm by 6mm--after it began to interfere with the patient’s daily life.
The New England Journal of Medicine reported the bizarre medical anomaly after it was submitted by doctors at Tabriz University of Medical Sciences in Tabriz, Iran.
“He did not have pain, but the mass caused vision defects, mild discomfort on blinking, and the intermittent sensation of the presence of a foreign body,” the journal reported.
The man said he had been born with the mass, but it had gradually been growing in size.
It had begun impairing his vision--his left eye was 20/20, but his right eye saw only 20/60.
The hairy cyst is about twice the size of libal dermoids that doctors usually see, Dr. Richard Meetz, a clinical professor at the Indiana University School of Optometry, told MailOnline.
Limbal dermoids are rare--occurring in about one in 10,000 patients.
“I have seen a couple in my career, but I’ve seen over a 10,000 patients,” he said.
The cysts are always congenital--developing in the womb when skin cells get misplaced in the eye as it is developing.
The hairy spot on the Iranian man’s eye is made of the same kinds of tissue that forms skin.
Cysts like the one pictured can occur in various places on the body.
They can grow can hair follicles, sweat glands and cartilage. In very rare cases, teeth can even form. However, Dr. Meetz said he is unsure whether a limbal dermoid with teeth had ever been found on an eyeball.
The biggest complication from limbal dermoids come from vision impairment. Because of the placement of the cyst on the eyeball, they warp a patient’s vision and can prevent sharp, clear eyesight from developing.

Deepest Corals in Great Barrier Reef Discovered

Even four times as deep as most scuba divers venture, the Great Barrier Reef blooms.
A new exploration by a remote-operated submersible has found the reef’s deepest coral yet, LiveScience said.
The common coral Leptoseris is living 410 feet (125 meters) below the ocean’s surface, a discovery that expedition leader Pim Bongaerts of the University of Queensland called “mind-blowing.”
Coral reefs are made of colonies of polyps which secret a rock-like exoskeleton. The polyps have a symbiotic relationship with algae that provide them nutrients using photosynthesis. Because this process requires light, coral reefs thrive in clear, relatively shallow water.
“The discovery shows that there are coral communities on the Great Barrier Reef existing at considerably greater depths than we could have ever imagined,” Bongaerts said in a statement.
Coral colonies
The 410-foot distance is surprising for the Great Barrier Reef, where scuba divers find stunning coral displays at depths down to 100 feet. But corals are known to live deep elsewhere. In the Gulf of Mexico, researchers have found the coral Lophelia pertusa thriving 2,620 feet (799 m) down. Lophelia doesn’t need sunlight to survive. In Puerto Rico, light-dependent corals survive as far down as 500 feet (150 m).
Bongaerts and his colleagues received funding from insurer the Catlin Group Limited to explore the Great Barrier Reef as part of an effort to understand how climate change is altering the oceans.
On the outer edge of the Ribbon Reefs, off the northern Great Barrier Reef, the researchers hit unusually calm seas and were able to deploy a remote-operated vehicle, or ROV, off the edge of the Australian continental shelf, where the ocean floor plummets hundreds of feet. It was a tough dive, said expedition member Paul Muir, a taxonomist from the Museum of Tropical Queensland.
“With more than 250 meters of cable out to provide power and communications with the ROV, it was a real struggle to collect a specimen of one of these corals,” Muir said in a statement.
The deep reef
The team persevered and brought one precious Leptoseris coral sample back to sea level. Typically, such corals peter out in the Great Barrier Reef above 330 feet (100 m), replaced by non-light-dependent sponges and sea fans. The team also found the deepest Staghorn Acropora, a type of coral that makes up the majority of most of the world’s reefs.

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