astrophysics popular medias
9 minutes ago
Nature 🌴🌎 .
Which one is your favorite ❤
Are you ready to explore every angle of Nature @natureveryangle 🌴🌎 .
Image credits: @jurkopagac
9 minutes ago
Novembre 1572, in cielo c’è una nuova stella: si chiama SN 1572 (sempre grande fantasia con i nomi eh). Oggi (foto NASA) vediamo una nube di gas che si espande nello spazio come un broccolo e sappiamo che SN 1572 è una supernova di tipo Ia, un fenomeno con due attrici: una stella normale e una nana bianca.
Che cos’è una nana bianca? Quando una stella tipo il Sole smette di avere reazioni di fusione nucleare, ci sono una serie di processi portano all’espulsione nello spazio del gas che si trova negli strati più esterni della stella. Ciò che resta poi è il nocciolo inerte della stella, fatto di nuclei atomici di carbonio e ossigeno ed elettroni. Questo nocciolo è una nana bianca, un oggetto con densità e gravità molto intense.
Come si tiene in piedi una nana bianca? Di solito la pressione della materia si oppone al peso di un corpo. Come la tinozza della vendemmia: se si preme con i piedi, l’uva regge il peso della persona.
In una nana bianca sono gli elettroni a tenere in piedi la baracca. Qui siamo a densità più elevate di quelle di una tinozza d’uva, e la pressione degli elettroni funziona come un cinema dove, anziché poltrone, ci sono divanetti a due posti. Per gli elettroni vale il principio di Pauli: in uno stato fisico non ci possono essere più di due elettroni insieme. Quindi gli elettroni della nana bianca vanno a occupare a coppie i divanetti del cinema; anche se magari c’è spazio su un divanetto, un elettrone non può andare su un divanetto già occupato da altri due. Che ansia, non vorrei mai essere un elettrone quando uscirà il nuovo film di Tarantino.
Con questo meccanismo si crea una specie di struttura robusta con cui una nana bianca si regge in piedi e sostiene il suo peso.
Ma questa situazione è precaria. Se infatti una nana bianca si trova vicino a una stella allora inizia a succhiarle il gas., il quale cade sulla nana bianca e aumenta la quantità di elettroni in cerca di divanetti. Quando poi la massa della nana bianca aumenta troppo e raggiunge un valore critico (circa 1,4 volte la massa del Sole), il cinema crolla, la nana bianca esplode.
Ecco una supernova di tipo Ia: bella, ma non ci vivrei. Meglio il Molise.
10 minutes ago
Please welcome our new member, Emily Deibert.
Emily is a PhD student and Vanier Scholar in the Department of Astronomy & Astrophysics at the University of Toronto. Prior to beginning her graduate students, Emily completed an undergraduate degree in Astronomy, English, and Mathematics from the University of Toronto as well. She is in the second year of her PhD program.
Emily’s research focuses on characterizing the atmospheres of exoplanets, which are planets orbiting stars other than the Sun. To do this, she uses extremely high-resolution telescopes located around the world. Although it’s difficult to study the atmospheres of other worlds from here on the ground—mainly because the Earth’s atmosphere gets in the way—Emily is researching advanced new techniques that will allow astronomers to get the best possible look into these strange new worlds.
Emily is also a science writer and communicator, and currently writes bi-weekly science articles for Research2Reality ( @research2reality), a Canadian organization shining a light on research and innovation across the country. She also runs the Research2Reality Instagram account, where she shares scientific stories from researchers in all disciplines.
In her spare time, Emily likes reading, biking, and traveling.
We welcome you to The Addictive Brain community and we look forward to reading your contributions about ‘Studying the Atmospheres of Other Worlds’
10 minutes ago
Astronomers right now, are looking up to monster Galaxy COSMOS-AzTEC-1 located 12.4 billion light-years away, which is forming stars 1000 times more rapidly than our Milky Way Galaxy!
🌌✨ (Typically, very active, starburst galaxies form stars at a pace some 100 times)
Using the Atacama Large Millimeter/submillimeter Array (ALMA), the team revealed that the molecular clouds in the galaxy are highly unstable, which leads to runaway star formation. Monster galaxies are thought to be the ancestors of the huge elliptical galaxies in today’s Universe, therefore these findings pave the way to understand the formation and evolution of such galaxies.
Are you ready to explore Space 🔭 @theourspace
Image credits: Artist’s concept ESOAstronomy
17 minutes ago
#Repost @sciencehumanist ( @get_repost)
This picture shows spectacular ribbons of gas and dust wrapping around the pearly centre of the barred spiral galaxy NGC 1398. This galaxy is located in the constellation of Fornax (The Furnace), approximately 65 million light-years away.
Rather than beginning at the very middle of the galaxy and swirling outwards, NGC 1398’s graceful spiral arms stem from a straight bar, formed of stars, that cuts through the galaxy’s central region. Most spiral galaxies — around two thirds — are observed to have this feature, but it’s not yet clear whether or how these bars affect a galaxy’s behaviour and development.
This image comprises data gathered by the FOcal Reducer/low dispersion Spectrograph 2 (FORS2) instrument, mounted on ESO’s Very Large Telescope (VLT) at Paranal Observatory, Chile. It shows NGC 1398 in striking detail, from the dark lanes of dust mottling its spiral arms, through to the pink-hued star-forming regions sprinkled throughout its outer regions.
This image was created as part of the ESO Cosmic Gems programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.
#ESO #Cosmology #Astronomy #Astrophysics #Science #Galaxy #VLT #Stars #Space #Universe
1 hour ago
The Laser Interferometer Space Antenna (LISA) is a forthcoming European space mission which aims to measure gravitational waves in a way not possible from Earth. Although not set for launch until 2034, scientists have calculated that LISA should be able to detect the existence of a theoretical particle called the ultralight boson.
This image is an artistic impression showing how the light boson would be detected. If light the particle does exists, theory suggests that they form bosonic clouds (the white donut) around massive black holes (black spiral in the centre of the cloud donut). When a smaller black hole (the small black spiral at the edge of the donut) orbits the bigger black hole-bosonic-cloud system, it emits gravitational waves. This signal provides a direct measurement of the ultralight boson which should be detectable by LISA (the red triangle, partially shown). .
The calculations were published recently in Nature Astronomy (doi.org/10.1038/s41550-019-0712-4) and first author Otto Hannuksela, a PhD student at the Chinese University of Hong Kong, provides some background and context on the Nature Research Astronomy Community: go.nature.com/2NF2YbJ (link in bio).
Artistic illustration by Antonio Mati.
#astronomy #astrophysics #particlephysics #quantumphysics #planetaryscience #blackhole #space #gravitationalwaves #theoreticalphysics #boson
1 hour ago
If you’re outside the event horizon, being near a black hole is no different than being near any other source of gravity. If the Sun were surreptitiously replaced by a black hole of the exact same mass — 1.99 × 10^30 kg the Earth and all the planets would continue in their orbits in exactly the same fashion they’re moving right now. The reason quasars do what they do, so to speak, is because these incredibly large masses can accelerate matter near them to very rapid speeds.The matter itself forms an accretion disk around the black hole, where it gets accelerated to speeds so great that they give off radiation of many different frequencies, including in the radio. We also see two “lobes” perpendicular to the accretion disk, which are jets of accelerated matter getting ejected at relativistic speeds. The sources we call blazars happen to be oriented with one of the lobes/jets pointed right towards us, while other active galaxies tend to be oriented otherwise. Quasars shine as brightly as they do because the things they devour get stretched apart, torn into bits, and accelerated by the irresistible force of gravity. They put out so much energy because that matter interacts with other bits of matter, heats up and has no choice but to emit radiation. And they’re visible from such great distances because these are black holes hundreds of millions or even billions of times the mass of our Sun, devouring millions of solar masses worth of matter but not devouring tens or hundreds of millions more..
nature #science #theorticalphysics #thermodynamics #physics #astronomer #astronomy #nasa🚀 #nebula #galaxy #knowledge #particlephysics #universe #cosmology #cosmologist #astrophysics #scientist #elonmusk #spacex #stellarphysics #interstellar #education #exploration #star #astrophysicist #hubblespacetelescope #hubble #quantumphysics #gravitationalwaves #physicist #realtivity
2 hours ago
An international research team led by the University of Göttingen has discovered two new Earth-like planets near one of our closest neighboring stars. "Teegarden's star" is only about 12.5 light years away from Earth and is one of the smallest known stars. It is only about 2,700 °C warm and about ten times lighter than the Sun. Although it is so close to us, the star wasn't discovered until 2003. The scientists observed the star for about three years. The results were published in the journal Astronomy and Astrophysics. Their data clearly show the existence of two planets. "The two planets resemble the inner planets of our solar system," explains lead author Mathias Zechmeister of the Institute for Astrophysics at the University of Göttingen. "They are only slightly heavier than Earth and are located in the so-called habitable zone, where water can be present in liquid form." The astronomers suspect that the two planets could be part of a larger system. "Many stars are apparently surrounded by systems with several planets," explains co-author Professor Stefan Dreizler of the University of Göttingen. Teegarden's star is the smallest star where researchers have so far been able to measure the weight of a planet directly. "This is a great success for the Carmenes project, which was specifically designed to search for planets around the lightest stars," says Professor Ansgar Reiners of the University of Göttingen, one of the scientific directors of the project.
#world2019 #9 #divinefeminine #divinemasculine #spirituality #spiritualawake #humanrace #planetlovers #newdiscoveries #earthlikeplanets #teegardens #stars #125light #years #astronomy #astrophysics #Scientists #habitalzone #water #liquidform #measure #weight #smalleststar #lighterthanthesun #iloveastronomy #iloveastrophysics #research #shows