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Science & Technology » Astronomy and Space Sciences Share

Solving the star-formation puzzle

Solving the star-formation puzzle

New Delhi, Feb 8 (UNI) Using measurements taken by radio antennas, a group of astrophysicists from the RIKEN Star and Planet Formation Laboratory has found clues as to how gas from collapsing molecular clouds in star-forming regions of the universe find its way to the surface of the stars that are still at the formative stage.
One of the big puzzles in astrophysics is how stars like the sun manage to form from the collapsing molecular clouds.
Technically, he puzzle is known as the angular momentum problem in stellar formation.
The problem essentially is that the gas in the star-forming cloud has some rotation, which gives each element of the gas an amount of angular momentum.
As it collapses inward, eventually it reaches a state where the gravitational pull of the nascent star is balanced by the centrifugal force, so that it will no longer collapse inward of a certain radius unless it can shed some of the angular momentum.
This point is known as the centrifugal barrier.
To gain a better understanding of the process, Nami Sakai and her group turned to the ALMA observatory, a network of 66 radio dishes located high in the Atacama Desert of northern Chile.
The research has been published in the Monthly Notices of the Royal Astronomical Society published by Oxford University Press.
The ALMA dishes are connected together in a carefully choreographed configuration so that they can provide images on radio emissions from protostellar regions around the sky.
The group chose to observe a protostar designated as L1527, located in a nearby star-forming region known as the Taurus Molecular Cloud.
The protostar, located about 450 light years away, has a spinning protoplanetary disk, almost edge-on to our view, embedded in a large envelope of molecules and dust.
Previously, Sakai had discovered, from observations of molecules around the same protostar, that unlike the commonly held hypothesis, the transition from envelope to the inner disk-which later forms into planets-was not smooth but very complex.
"As we looked at the observational data," says Sakai, "we realized that the region near the centrifugal barrier-where particles can no longer infall-is quite complex, and we realized that analysing the movements in this transition zone could be crucial for understanding how the envelope collapses,” she says.
The observations showed that there is a broadening of the envelope at that place, indicating something like a "traffic jam" in the region just outside the centrifugal barrier, where the gas heats up as the result of a shock wave.
It became clear from the observations that a significant part of the angular momentum is lost by gas being cast in the vertical direction from the flattened protoplanetary disk that formed around the protostar.
This behaviour accorded well with calculations the group had done using a purely ballistic model, where the particles behave like simple projectiles that do not need to be influenced by magnetic or other forces.
"We plan to continue to use observations from the powerful ALMA array to further refine our understanding of the dynamics of stellar formation and fully explain how matter collapses onto the forming star,” says Sakai.
“This work could also help us to better understand the evolution of our own solar system.
" UNI YSG SHS RAI1205

Cipla

Cipla Receives Final Approval for Generic Pulmicort Respules

Mumbai, Nov 17(UNI) Pharma major, Cipla Ltd, today said that it
has received final approval for its Abbreviated New Drug Application
(ANDA) for Budesonide Inhalation Suspension, 0.

Antibiotic

Antibiotic resistance is one of the biggest threats to global health

Kolkata, Nov 14 (UNI) Antibiotic resistance is one of the biggest threats to global health, food security and development today.

Drop

Drop in cases of plague in Madagascar: WHO

Geneva, Nov 4 (UNI) While progress has been made in response to the plague outbreak in Madagascar, and the number of suspected new cases continues to decline, the World Health Organisation (WHO) has said that sustaining operations through the remainder of the plague season would be critical as there was still a risk of potential further spread of the disease.

Hepatitis

Hepatitis C, a liver disease caused by the hepatitis C virus

Kolkata, Nov 1 (UNI) Hepatitis C is a liver disease caused by the hepatitis C virus: the virus can cause both acute and chronic hepatitis, ranging in severity from a mild illness lasting a few weeks to a serious, lifelong illness.

As

As India stares at breast cancer epidemic, CURA launches robotic device for early detection

Chennai, Oct 31 (UNI) India was staring at a breast cancer epidemic and breast screening was virtually non-existent in India as one in 28 women get breast cancer and one in two die due to late detection, making survival one of the lowest in the world.

Solar eclipse 2017: North America will witness total solar eclipse

Solar eclipse 2017: North America will witness total solar eclipse

New York, Aug 21 (UNI) Today, all of North America will witness a total solar eclipse for the first time in 99 years, where the Moon will pass in front of the Sun, casting darkness across swathes of the Earth's surface - with up to 14 states shrouded in complete blackout.

Nano-particle fertilizer could lead to new 'green revolution'

Nano-particle fertilizer could lead to new 'green revolution'

New Delhi, Jan 26 (UNI) Sri Lankan scientists report having developed a simple way to make a benign, more efficient fertilizer – described as nano-particle fertilizer - that could contribute to a second food revolution across the globe.

Broken pebbles offer clues to Palaeolithic funeral rituals

Broken pebbles offer clues to Palaeolithic funeral rituals

New Delhi, Feb 9 (UNI) Humans may have ritualistically "killed" objects to remove their symbolic power, some 5,000 years earlier than previously thought, a new international study of marine pebble tools from an Upper Palaeolithic burial site in Italy suggests.

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