First clear image made of accretion disk surrounding young star

center_img © 2017 Phys.org Astrophysics have theorized that accretion disks form around young stars acting as food, helping the young star to grow bigger. Such an accretion disk would also make up the material that would over time accrete into planets. But until now, no clear image of an accretion disk had been made because the technology to do so did not exist. Now, thanks to hard work by the team and the ALMA radio telescope in Chile, that has changed.ALMA came online just four years ago—at a cost of $1.4 billion, it holds the record for the most expensive radio telescope ever built. But it also offers unprecedented resolution, capturing images in sharp detail that have appeared as fuzzy blobs in prior images. That resolution allowed the researchers to zoom in on a young star named IRAS 05413-0104 (part of the HH212 system and believed to be just 40,000 years old) that had around it a rotating accretion disk. Such disks are believed to be made of matter such as silicate, iron and other interstellar matter, and provide a steady source of food for the star. And because the disks are triple layered with brighter outer layers, the researchers describe it as looking like a hamburger. More information: Chin-Fei Lee et al. First detection of equatorial dark dust lane in a protostellar disk at submillimeter wavelength, Science Advances (2017). DOI: 10.1126/sciadv.1602935AbstractIn the earliest (so-called “Class 0”) phase of Sun-like (low-mass) star formation, circumstellar disks are expected to form, feeding the protostars. However, these disks are difficult to resolve spatially because of their small sizes. Moreover, there are theoretical difficulties in producing these disks in the earliest phase because of the retarding effects of magnetic fields on the rotating, collapsing material (so-called “magnetic braking”). With the Atacama Large Millimeter/submillimeter Array (ALMA), it becomes possible to uncover these disks and study them in detail. HH 212 is a very young protostellar system. With ALMA, we not only detect but also spatially resolve its disk in dust emission at submillimeter wavelength. The disk is nearly edge-on and has a radius of ~60 astronomical unit. It shows a prominent equatorial dark lane sandwiched between two brighter features due to relatively low temperature and high optical depth near the disk midplane. For the first time, this dark lane is seen at submillimeter wavelength, producing a “hamburger”-shaped appearance that is reminiscent of the scattered-light image of an edge-on disk in optical and near infrared light. Our observations open up an exciting possibility of directly detecting and characterizing small disks around the youngest protostars through high-resolution imaging with ALMA, which provides strong constraints on theories of disk formation. Journal information: Science Advances Play Video explaining how a “dusty hamburger” (an accretion disk) feeds a central young star, or protostar, during the onset of an extra-solar system. Credit: Chin-Fei Lee/Lauren/ASIAA The captured image lays to rest one critique of the prediction of accretion disks around young stars, which was that the magnetic field from the core of the star would be so strong that it would prevent the accretion disk from spinning, thus preventing its ability to gather matter. That is clearly not the case, as the new image shows. Also seen in the image were gaseous jets ejected from the star, which appear to pierce the hamburger at its center.It is believed that more information about the formation of stars will contribute to understanding both the history of our sun and how planets form, perhaps offering a better way of filtering star systems while searching for signs of life beyond our own planet. Citation: First clear image made of accretion disk surrounding young star (2017, April 20) retrieved 18 August 2019 from https://phys.org/news/2017-04-image-accretion-disk-young-star.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Her story

first_imgAmerican Center in collaboration with Cinedarbaar aims to celebrate creative works of women through leading actresses and directors that have contributed to the American Cinema successfully and have charmed the audience world over with their exceptional talents. The 3 day festival from 27 – 29 March will showcase 5 movies at the American Center Auditorium (basement level) 24 Kasturba Gandhi Marg.‘Women’s History Month Film Festival’ will open with A Woman under the Influence byJohn Cassavetes. Each day the film showcase will be followed by an interactive session and an interesting quiz with exciting prizes. Do not miss out for an interesting session on the first day, about the relationship between the husband and wife duo of Gena Rowlands and John Cassavetes and their collaboration over 10 films. As a takeaway, the visitors will get informative handouts acknowledging the exceptional works of the women directors and actresses. Also Read – ‘Playing Jojo was emotionally exhausting’The festival will focus on auteur and actresses by showcasing their films which have been critically acclaimed & won several awards. The powerful performance by Gena Rowlands in A Woman under the Influence is often acclaimed as the finest performance by any actress ever committed to the big screen. Similarly Faye Dunaway in 1977 won the award for Best Actress in a Leading Role in the movie Network.  She turned this incredibly difficult character into gold. Other contemporary actresses like Scarlett Johansson have worked with some of the finest directors and their performances have been critically acclaimed like in the Ghost World. Also Read – Leslie doing new comedy special with NetflixHollywood has seen some of the big box office hits by the women directors whose movies will be a part of the film festival. Martha Coolidge has proved to be one of Hollywood’s most successful commercial director. With Real Genius an incredibly humorous and wonderful film, she has proved her talent yet again. Kathryn Bigelow became the first woman in Oscar history to win the Best Director award in 2010. However, her earlier work features some stunning films that showcase a brilliant visionary style, and no other movie reflects that better than Strange Days. It was nominated for several Saturn Awards including Best Science Fiction Film with Bigelow winning for Best Director.The entry to the festival is free and is on first come first serve basis. Entry is open for general public but by invitation only. E-mail to [email protected] or collect passes from the American Center. And yes, carry a valid photo ID to enter and an e-invite (poster’s print copy).WHEN: 27 to 29 MarchWHERE: American Center Auditorium (basement level)last_img read more

Net Neutrality Explained

first_img This story originally appeared on CNBC Register Now » Growing a business sometimes requires thinking outside the box. 2 min read Watching “House of Cards,” listening to Kayne West’s new album or emailing your mother. These daily, instinctive Internet actions are available to all of us anytime, free of charge, in what is known as net neutrality–the concept that Internet providers can’t discriminate between different types of content, such as movies and video.But this level playing field may soon be changing. Network giants, such as telephone and cable companies, are rallying to institute a “tiered” Internet, where broadband providers could offer speedier service and smoother access to those consumers who agree to pay a premium price for it.Think of the Internet as a highway with toll booths. Under the old policy of the open Internet, Internet companies weren’t allowed to distinguish between one kind of traffic or another. Under the new policies, these Internet providers would be allowed to charge more for different types of traffic, like streaming movies and music. If this happens, you will likely see an increase in your monthly bill.At this moment the FCC is working on a policy to ensure that Internet providers do not charge differently for consuming different types of content.If you think a provider has been in violation of the Open Internet rule, you can file a complaint with the FCC. Free Webinar | Sept. 9: The Entrepreneur’s Playbook for Going Global April 16, 2014last_img read more