Spiral Arms Embrace Young Star; First Direct Evidence for Density Waves in a Protoplanetary Disk
Swirling around the young star Elias 2-27 is a stunning spiral-shape pinwheel of dust. This striking feature, seen with the Atacama Large Millimeter/submillimeter Array (ALMA), is the product of density waves – gravitational perturbations in the star’s protoplanetary disk that produce sweeping arms reminiscent of a spiral galaxy, but on a much smaller scale.
“These observations are the first direct evidence for density waves in a protoplanetary disk,” said Laura Pérez, an astronomer and Alexander von Humboldt Research Fellow with the Max Planck Institute for Radio Astronomy in Bonn, Germany, and lead author on a paper published in the journal Science.
Nearest to the star, ALMA found a familiar flattened disk of dust, which extends past what would be the orbit of Neptune in our own solar system. Beyond that point, ALMA detected a narrow band with significantly less dust, which may be indicative of a planet in formation. Springing from the outer edge of this gap are two sweeping spiral arms that extend more than 10 billion kilometers away from their host star.
Finding density waves at these extreme distances may have implications for planet-formation theory, Pérez notes. The standard picture of planet formation begins with small planetesimals coming together under gravity. In the outer reaches of a protoplanetary disk, where there is a dearth of planetesimals, disk instabilities may also lead directly to the formation of a planet. ALMA’s detection of spiral density waves may be evidence that such a process is taking place.
Elias 2-27 is located approximately 450 light-years from Earth in the Ophiuchus star-forming complex. Even though it contains only about half the mass of our Sun, this star has an unusually massive protoplanetary disk. The star is estimated to be at least one million years old and still encased in its parent molecular cloud, obscuring it from optical telescopes.
“There are still questions of how these features form. Perhaps they are the result of a newly forged planet interacting with the protoplanetary disk or simply gravitational instabilities driven by the shear mass of the disk,” said Andrea Isella, an astronomer at Rice University in Houston, Texas, and co-author of the paper.
“Fortunately, the power of ALMA will be used in the future to answer this puzzle,” concludes Pérez. “ALMA will further dissect this and other similar disks in an upcoming large program, helping astronomers understand the seemingly chaotic forces that eventually give rise to stable planetary systems like our own.”
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.
Source:
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world. Anyone can join. Anyone can contribute. Anyone can become informed about their world. "United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
LION'S MANE PRODUCT
Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules
Mushrooms are having a moment. One fabulous fungus in particular, lion’s mane, may help improve memory, depression and anxiety symptoms. They are also an excellent source of nutrients that show promise as a therapy for dementia, and other neurodegenerative diseases. If you’re living with anxiety or depression, you may be curious about all the therapy options out there — including the natural ones.Our Lion’s Mane WHOLE MIND Nootropic Blend has been formulated to utilize the potency of Lion’s mane but also include the benefits of four other Highly Beneficial Mushrooms. Synergistically, they work together to Build your health through improving cognitive function and immunity regardless of your age. Our Nootropic not only improves your Cognitive Function and Activates your Immune System, but it benefits growth of Essential Gut Flora, further enhancing your Vitality.
Our Formula includes: Lion’s Mane Mushrooms which Increase Brain Power through nerve growth, lessen anxiety, reduce depression, and improve concentration. Its an excellent adaptogen, promotes sleep and improves immunity. Shiitake Mushrooms which Fight cancer cells and infectious disease, boost the immune system, promotes brain function, and serves as a source of B vitamins. Maitake Mushrooms which regulate blood sugar levels of diabetics, reduce hypertension and boosts the immune system. Reishi Mushrooms which Fight inflammation, liver disease, fatigue, tumor growth and cancer. They Improve skin disorders and soothes digestive problems, stomach ulcers and leaky gut syndrome. Chaga Mushrooms which have anti-aging effects, boost immune function, improve stamina and athletic performance, even act as a natural aphrodisiac, fighting diabetes and improving liver function. Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules Today. Be 100% Satisfied or Receive a Full Money Back Guarantee. Order Yours Today by Following This Link.
