Infographic about Planet 9, the required planet to explain the trajectory of six of the most distand known Kuiper Belt Objects.
Source: http://imgur.com/S5faizX
ESO - European Southern Observatory logo. 13 July 2016
Artist’s impression of the water snowline around the young star V883 Orionis
The Atacama Large Millimeter/submillimeter Array (ALMA) has made the first ever resolved observation of a water snow line within a protoplanetary disc. This line marks where the temperature in the disc surrounding a young star drops sufficiently low for snow to form. A dramatic increase in the brightness of the young star V883 Orionis flash heated the inner portion of the disc, pushing the water snow line out to a far greater distance than is normal for a protostar, and making it possible to observe it for the first time. The results are published in the journal Nature on 14 July 2016.
ALMA image of the protoplanetary disc around V883 Orionis
Young stars are often surrounded by dense, rotating discs of gas and dust, known as protoplanetary discs, from which planets are born. The heat from a typical young solar-type star means that the water within a protoplanetary disc is gaseous up to distances of around 3 au from the star [1] — less than 3 times the average distance between the Earth and the Sun — or around 450 million kilometres [2]. Further out, due to the extremely low pressure, the water molecules transition directly from a gaseous state to form a patina of ice on dust grains and other particles. The region in the protoplanetary disc where water transitions between the gas and solid phases is known as the water snow line [3].
The star V883 Orionis in the constellation of Orion
But the star V883 Orionis is unusual. A dramatic increase in its brightness has pushed the water snow line out to a distance of around 40 au (about 6 billion kilometres or roughly the size of the orbit of the dwarf planet Pluto in our Solar System). This huge increase, combined with the resolution of ALMA at long baselines [4], has allowed a team led by Lucas Cieza (Millennium ALMA Disk Nucleus and Universidad Diego Portales, Santiago, Chile) to make the first ever resolved observations of a water snow line in a protoplanetary disc.
Shifting water snowline in V883 Orionis
The sudden brightening that V883 Orionis experienced is an example of what occurs when large amounts of material from the disc surrounding a young star fall onto its surface. V883 Orionis is only 30% more massive than the Sun, but thanks to the outburst it is experiencing, it is currently a staggering 400 times more luminous — and much hotter [5].
ALMA image of the protoplanetary disc around V883 Orionis (annotated)
Lead author Lucas Cieza explains: “The ALMA observations came as a surprise to us. Our observations were designed to look for disc fragmentation leading to planet formation. We saw none of that; instead, we found what looks like a ring at 40 au. This illustrates well the transformational power of ALMA, which delivers exciting results even if they are not the ones we were looking for.”
ALMA image of the protoplanetary disc around V883 Orionis
The bizarre idea of snow orbiting in space is fundamental to planet formation. The presence of water ice regulates the efficiency of the coagulation of dust grains — the first step in planet formation. Within the snow line, where water is vapourised, smaller, rocky planets like our own are believed to form. Outside the water snow line, the presence of water ice allows the rapid formation of cosmic snowballs, which eventually go on to form massive gaseous planets such as Jupiter.
Zooming on the protoplanetary disc around V883 Orionis
The discovery that these outbursts may blast the water snow line to about 10 times its typical radius is very significant for the development of good planetary formation models. Such outbursts are believed to be a stage in the evolution of most planetary systems, so this may be the first observation of a common occurrence. In that case, this observation from ALMA could contribute significantly to a better understanding of how planets throughout the Universe formed and evolved.
The protoplanetary disc around V883 Orionis (artist’s impression)
Notes: [1] 1 au, or one astronomical unit, is the mean distance between the Earth and the Sun, around 149.6 million kilometres.This unit is typically used to describe distances measured within the Solar System and planetary systems around other stars. [2] This line was between the orbits of Mars and Jupiter during the formation of the Solar System, hence the rocky planets Mercury, Venus, Earth and Mars formed within the line, and the gaseous planets Jupiter, Saturn, Uranus and Neptune formed outside. [3] The snow lines for other molecules, such as carbon monoxide and methane, have been observed previously with ALMA, at distances of greater than 30 au from the protostar within other protoplanetary discs. Water freezes at a relatively high temperature and this means that the water snow line is usually much too close to the protostar to observe directly. [4] Resolution is the ability to discern that objects are separate. To the human eye, several bright torches at a distance would seem like a single glowing spot, and only at closer quarters would each torch be distinguishable. The same principle applies to telescopes, and these new observations have exploited the exquisite resolution of ALMA in its long baseline modes. The resolution of ALMA at the distance of V883 Orionis is about 12 au — enough to resolve the water snow line at 40 au in this outbursting system, but not for a typical young star. [5] Stars like V883 Orionis are classed as FU Orionis stars, after the original star that was found to have this behaviour. The outbursts may last for hundreds of years. More information: This research was presented in a paper entitled “Imaging the water snow-line during a protostellar outburst”, by L. Cieza et al., to appear in Nature on 14 July 2016. The team is composed of Lucas A. Cieza (Millennium ALMA Disk Nucleus; Universidad Diego Portales, Santiago, Chile), Simon Casassus (Universidad de Chile, Santiago, Chile), John Tobin (Leiden Observatory, Leiden University, The Netherlands), Steven Bos (Leiden Observatory, Leiden University, The Netherlands), Jonathan P. Williams (University of Hawaii at Manoa, Honolulu, Hawai`i, USA), Sebastian Perez (Universidad de Chile, Santiago, Chile), Zhaohuan Zhu (Princeton University, Princeton, New Jersey, USA), Claudio Cáceres (Universidad Valparaiso, Valparaiso, Chile), Hector Canovas (Universidad Valparaiso, Valparaiso, Chile), Michael M. Dunham (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Antonio Hales (Joint ALMA Observatory, Santiago, Chile), Jose L. Prieto (Universidad Diego Portales, Santiago, Chile), David A. Principe (Universidad Diego Portales, Santiago, Chile), Matthias R. Schreiber (Universidad Valparaiso, Valparaiso, Chile), Dary Ruiz-Rodriguez (Australian National University, Mount Stromlo Observatory, Canberra, Australia) and Alice Zurlo (Universidad Diego Portales & Universidad de Chile, Santiago, Chile). The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA. ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”. Links: Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1626/eso1626a.pdf Photos of ALMA: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Atacama%20Large%20Millimeter/submillimeter%20Array For more information about ALMA, visit: https://www.eso.org/sci/facilities/alma.html Images, Text, Credits: ESO/Richard Hook/A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)/ALMA//L. Cieza/IAU and Sky & Telescope/Videos: ALMA (ESO/NAOJ/NRAO)/L. Cieza./ESO/Digitized Sky Survey 2/N. Risinger (skysurvey.org)/M. Kornmesser. Music: Johan B. Monell. Best regards, Orbiter.ch Full article
▪︎Copernican armillary sphere.
Date: 1807-1846
Place of origin: Paris
From the source: Copernican armillary sphere from set of two armillary spheres and a celestial globe constructed in paper on pasteboard with metal fitments supported on a decorative mahogany baluster base. Shows planets out to Uranus, plus four asteroids, Ceres, Pallas, Juno & Vesta, first quarter 19th century.
Got these notebooks for 5 cents so obviously going to buy more than one :D # strongnotebookgameisstrong
There’s a method to my madness I swear!! OK so on avg I seem to use up two of those 80 pg notebooks so I got two for each class. And consequently I needed the 4pack 32pg exercise books.
The 80 page notebook is used for in class notes. As soon as anything important is said it is scribbled down into the notebook. The 4 pack 32 pg exercise book is divided to two groups: Feymann technique and Cornell method.
Feymann Technique
Right after class I grab my textbook, my notebooks and two of my exercise books. I teach myself the lesson primarily with my notes and if I don’t understand something I turn to my textbook. If I am still lost I leave space and note that there is something I need to clarify with my professor. Even while I am doing this, I force myself to decrease the writing and increase the connections between every topic since the 32 pg is quite smaller than the 80 pg.
Thankfully when I am done with this, my 32pg becomes the go to whenever it seems like I am in need of revising a topic since it contains relevant notes from both my textbook and my notebook in my own words.
Cornell Method.
When exam time approaches I convert my notes into the cornell notes so that I can easily test myself with the main ideas and key questions.
There is no better way to revise than to try to make connections. That is all you are going to get tested on since it’s not that hard to spit back words on a page. Instead of being asked about photosynthesis for example, you might be told about some chemical that is sprayed on a plant that will block one process and asked about how that affects the growth of the plant overall. See what I mean?
I usually get a whiteboard and write all of the connections out and in front of me. When THAT is done I write it down in flashcard mode and quiz myself for the next week using the Leitner system, along with the topics that are basically just memorization.
LEITNER SYSTEM
Label 5 boxes 1-4, where 1 is for cards you don’t know and 4 is for cards you are basically a pro in. You frequently test yourself in box 1 (maybe every 30 mins, you choose) and increase the time in which you test yourself until you reach 4, where you would test yourself just once a day.
In the beginning all of your cards go in box 1,and as you get a card right it goes up a level and if you get it wrong it goes down a level. That way you are spending more time with ideas and topics you don’t have a strong hold on, rather than spending equal time with all the topics.
At this point I have rewritten my notes twice in my own words and then converted them into flashcard mode :) I recommend this method when it comes to the sciences or humanities. For the maths I have already done a post about it here.
Hope this helps for those still looking for study techniques!
-F
NASA’s announcement today was awe-inspiring. We’ve compiled the essential info you want to know about this incredible discovery.
OVERVIEW: 7 PLANETS, 3 HABITABLE
Astronomers have found at least seven Earth-sized planets orbiting the same star 40 light-years away, according to a study published Wednesday in the journal Nature.
The seven exoplanets were all found in tight formation around an ultracool dwarf star called TRAPPIST-1. Estimates of their mass also indicate that they are rocky planets, rather than being gaseous like Jupiter. Three planets are in the habitable zone of the star, known as TRAPPIST-1e, f and g, and may even have oceans on the surface.
“I think we’ve made a crucial step towards finding if there is life out there,” said Amaury Triaud, one of the study authors and an astronomer at the University of Cambridge. “I don’t think any time before we had the right planets to discover and find out if there was (life). Here, if life managed to thrive and releases gases similar to what we have on Earth, we will know.”
ONLY 40 LIGHT YEARS AWAY
The system is just 40 light-years away. On a cosmic scale, that’s right next door. Of course, practically speaking, it would still take us hundreds of millions of years to get there with today’s technology – but again, it is notable in that the find speaks volumes about the potential for life-as-we-know-it beyond Earth.
The Hubble Space Telescope is already being used to search for atmospheres around the planets, and Emmanuël Jehin, a scientist who also worked on the research, asserts that future telescopes could allow us to truly see into the heart of this system: “With the upcoming generation of telescopes, such as ESO’s European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope, we will soon be able to search for water and perhaps even evidence of life on these worlds.”
ALIEN SKIES
In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
WOW!!
This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole’s event horizon, where no light can escape the massive object’s gravitational grip. The black hole’s powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.
Credits: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)
Full Story at Hubble Space Telescope/NASA.- Behemoth Black Hole Found in an Unlikely Place
High-res images at HubbleSite.org
It’s a baby bat ray brunch! Using plate-like teeth to grind and chew their sustainable seafood, these youngsters will grow quickly into their role as majestic sea flap flaps.
This is a studyblr for everyone have some passion for science, especially astronomy and biology
129 posts