T Tauri stars

T Tauri stars are less than 10 million years old. A star begins its life as a protostar still enveloped in its molecular cloud. Over the years the newborn star accretes new material from the surrounding area and develops a proto-planetary disc. Slowly, stellar winds and radiation blow away the gas and dust and when the surrounding shell is all cleared up, the star enters the T-Tauri phase. SUBSCRIBE ► https://goo.gl/PLLFPz ---- Website ► cosmoknowledge.com Facebook ► https://facebook.com/cosmoknowledgee Instagram ► https://www.instagram.com/itscosmoknowledge Twitter ► https://www.twitter.com/cosmoknowledge Narrator: Russell Archey https://www.ravonmedia.com/ Credits: NASA/Goddard Space Flight Center and the National Center for Supercomputing Applications Music: Whirlwinds - Farrell Wooten - Cosmoknowledge brings news from space. We love you, explorers!

Text at http://howfarawayisit.com/wp-content/uploads/2019/10/How-Old-Is-It-03-Stars.pdf In this chapter of the “How Old Is It” video book, we’ll cover stars – second generation stars. We start with giant molecular clouds and what may trigger their collapse into star clusters. We’ll follow their size, density, and temperature as they move from hydrostatic equilibrium to fragments to stars. We’ll then follow the collapse of a fragment capable of creating a star like our Sun. We’ll cover how circumstellar disks around central massive objects are formed. We’ll cover the Protostar phase and examine a few like the ones in the Eagle Nebula and Orion. We’ll cover T-Tauri stars, their properties, and examine several including T Tauri itself, XZ Tauri, and others. We’ll cover how these giant molecular clouds form Open and Globular clusters and how Field Stars like our Sun have left their starting clusters. We’ll follow stars as they start burning hydrogen and migrate to the Main Sequence on the H-R Diagram. We’ll take a deep dive into the hydrogen fusion that powers stars. With a focus on our Sun, we’ll compute proton collision and fusion rates. In order to understand the mass-luminosity relationship better, we’ll cover the Coulomb Barrier and how Tunneling through it works. And finally, we’ll examine what happens to a star once it runs out of hydrogen fuel.

"T Tauri stars" are a class of variable stars named after their prototype – T Tauri. They are found near molecular clouds and identified by their optical variability and strong chromospheric lines. T Tauri stars are pre-main sequence stars in the process of contracting to the main sequence along the Hayashi track, a luminosity-temperature relationship obeyed by infant stars of less than 3 solar masses in the pre-main-sequence phase of stellar evolution. It ends when a star of develops a radiative zone, or when a larger star commences nuclear fusion on the main sequence. T Tauri stars are the youngest visible F, G, K, M spectral type stars . Their surface temperatures are similar to those of main sequence stars of the same mass, but they are significantly more luminous because their radii are larger. Their central temperatures are too low for hydrogen fusion. Instead, they are powered by gravitational energy released as the stars contract, while moving towards the main sequence, which they reach after about 100 million years. They typically rotate with a period between one and twelve days, compared to a month for the Sun, and are very active and variable. There is evidence of large areas of starspot coverage, and they have intense and variable X-ray and radio emissions . Many have extremely powerful stellar winds; some eject gas in high-velocity bipolar jets. Another source of brightness variability are clumps in the disk surrounding T Tauri stars. Wiz Science™ is "the" learning channel for children and all ages. SUBSCRIBE TODAY Disclaimer: This video is for your information only. The author or publisher does not guarantee the accuracy of the content presented in this video. USE AT YOUR OWN RISK. Background Music: "The Place Inside" by Silent Partner (royalty-free) from YouTube Audio Library. This video uses material/images from https://en.wikipedia.org/wiki/T+Tauri+star, which is released under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . This video is licensed under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . To reuse/adapt the content in your own work, you must comply with the license terms. Wiz Science™ is "the" learning channel for children and all ages. SUBSCRIBE TODAY Disclaimer: This video is for your information only. The author or publisher does not guarantee the accuracy of the content presented in this video. USE AT YOUR OWN RISK. Background Music: "The Place Inside" by Silent Partner (royalty-free) from YouTube Audio Library. This video uses material/images from https://en.wikipedia.org/wiki/T+Tauri+star, which is released under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . This video is licensed under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . To reuse/adapt the content in your own work, you must comply with the license terms.

Today Phil’s explaining the stars and how they can be categorized using their spectra. Together with their distance, this provides a wealth of information about them including their luminosity, size, and temperature. The HR diagram plots stars’ luminosity versus temperature, and most stars fall along the main sequence, where they live most of their lives. -- Table of Contents Stars Can Be Categorized Using Their Spectra 1:32 Spectra With Distance Can Identify Luminosity, Size, and Temperature 5:20 The HR Diagram Plots Luminosity vs Temperature 6:33 Most Stars Fall Along the Main Sequence 7:16 -- PBS Digital Studios: http://youtube.com/pbsdigitalstudios Follow Phil on Twitter: https://twitter.com/badastronomer Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Patreon: http://www.patreon.com/crashcourse -- PHOTOS/VIDEOS Stars http://www.nasa.gov/images/content/703724main_potw1244a.jpg [credit: ESA/Hubble & NASA] Spitzer Spectrum http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA03242 [credit: NASA/JPL-Caltech/Leiden/SRON] Sun spectrum https://www.noao.edu/image_gallery/html/im0600.html [credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF] Annie Jump Cannon https://en.wikipedia.org/wiki/Annie_Jump_Cannon#/media/File:Annie_Jump_Cannon_1922_Portrait.jpg [credit: New York World-Telegram and the Sun Newspaper] Cecilia Payne-Gaposchkin https://en.wikipedia.org/wiki/Cecilia_Payne-Gaposchkin#/media/File:Cecilia_Helena_Payne_Gaposchkin_(1900-1979)_(3).jpg [credit: Smithsonian Institution] OBAFGKM https://www.noao.edu/image_gallery/html/im0649.html [credit: NOAO/AURA/NSF] Betelgeuse http://www.eso.org/public/usa/images/eso0927e/ [credit: ESO/Digitized Sky Survey 2. Acknowledgment: Davide De Martin] Sirius https://www.nasa.gov/multimedia/imagegallery/image_feature_468.html [credit: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester)] Solar AM0 spectrum with visible spectrum background https://commons.wikimedia.org/wiki/File:Solar_AM0_spectrum_with_visible_spectrum_background_(en).png [credit: Danmichaelo, Wikimedia Commons] Blue sky http://www.pexels.com/photo/sky-sunny-clouds-cloudy-3768/ [credit: Skitter Photo] Hawaii sunset photo [credit: Phil Plait] Hertzsprung-Russell Diagram https://commons.wikimedia.org/wiki/File:ESO_-_Hertzsprung-Russell_Diagram_(by).jpg [credit: ESO]

http://www.teachastronomy.com/ The most important pre-main sequence stars are called T Tauri stars, named after the twentieth cataloged variable star in the constellation of Taurus. T Tauri stars are transitions between infrared stars in opaque cocoons or nebulae and stable stars settling for the first time onto the main sequence. The density of T Tauri stars in a rich star forming region like the Orion nebula exceeds the density of all stars in the solar neighborhood. T Tauri stars vary irregular in their brightness and are very young in the range twenty thousand to only a million years old.