Wissenschaft und Deutsch
A Mysterious Ring
The European Space Agency’s Herschel space telescope pictured a puzzling ring (top, center) in the middle of a stellar nursery in this image released on June 12. The nursery, labeled NGC 7538, contains clumps of gas that astronomers believe could eventually give rise to O-type stars, the most massive stars in the universe.
Violent winds given off by these stars can result in bubble- or ring-shaped formations in their surrounding cloud of gas and dust. The death of O-type stars, in the stellar explosions called supernovae, can also produce these structures.
However, the remains of such a star are absent in the middle of this particular ring. It’s possible that one of the enormous stars blew this bubble, then scooted away before researchers were able to detect it, leaving behind the ring.
source 

A Mysterious Ring

The European Space Agency’s Herschel space telescope pictured a puzzling ring (top, center) in the middle of a stellar nursery in this image released on June 12. The nursery, labeled NGC 7538, contains clumps of gas that astronomers believe could eventually give rise to O-type stars, the most massive stars in the universe.

Violent winds given off by these stars can result in bubble- or ring-shaped formations in their surrounding cloud of gas and dust. The death of O-type stars, in the stellar explosions called supernovae, can also produce these structures.

However, the remains of such a star are absent in the middle of this particular ring. It’s possible that one of the enormous stars blew this bubble, then scooted away before researchers were able to detect it, leaving behind the ring.

source 

Hidden Hole
Photograph by Stéphane Guisard, European Southern Observatory
Viewed through an amateur telescope, the Milky Way’s dusty center sweeps diagonally across the sky, draping stellar nurseries. Behind the veil lurks the supermassive black hole at the center of our galaxy.
source

Hidden Hole

Photograph by Stéphane Guisard, European Southern Observatory

Viewed through an amateur telescope, the Milky Way’s dusty center sweeps diagonally across the sky, draping stellar nurseries. Behind the veil lurks the supermassive black hole at the center of our galaxy.

source

Astronomers for the first time have peered into the heart of a supernova that exploded 343 years ago. NASA’s NuSTAR mission has produced the first map of high-energy X-ray emissions from material created in the core of the exploding star.Read more: http://bit.ly/MKip1s via UC Berkeley
through Science Alert

Astronomers for the first time have peered into the heart of a supernova that exploded 343 years ago. NASA’s NuSTAR mission has produced the first map of high-energy X-ray emissions from material created in the core of the exploding star.

Read more: http://bit.ly/MKip1s via UC Berkeley

through Science Alert

Space photo weekend edition: The beautiful leftover debris from an exploded starhttp://wrd.cm/1mhpkPC
from wired science

Space photo weekend edition: The beautiful leftover debris from an exploded star

http://wrd.cm/1mhpkPC

from wired science

Tags: science stars
How are stars born? How do they die? 
You’ve probably been told that staring directly at the Sun is bad for your eyes. However, we don’t have to have uncomfortable staring contests with the Stars to try and get them to give up their secrets! After years and years of research, scientists have managed to find out quite a bit about the oh-so-secretive stars without losing a staring contest.     Firstly, stars go through the same process that we do in the sense that they are born, live, and then die. The difference is that they do it far more dramatically, and take a much longer time doing it. Depending on the mass of the star, the lifetime can range from a few million years to trillions of years! So let’s take a moment to get to know a little something about the lives of some of the oldest inhabitants of the universe: STARS.Learn about the lives of stars at:http://www.fromquarkstoquasars.com/how-are-stars-born-how-do-they-die/Image: NASA, open the image in a new tab to see larger 

source  

How are stars born? How do they die? 


You’ve probably been told that staring directly at the Sun is bad for your eyes. However, we don’t have to have uncomfortable staring contests with the Stars to try and get them to give up their secrets! After years and years of research, scientists have managed to find out quite a bit about the oh-so-secretive stars without losing a staring contest.
     Firstly, stars go through the same process that we do in the sense that they are born, live, and then die. The difference is that they do it far more dramatically, and take a much longer time doing it. Depending on the mass of the star, the lifetime can range from a few million years to trillions of years! So let’s take a moment to get to know a little something about the lives of some of the oldest inhabitants of the universe: STARS.
Learn about the lives of stars at:
http://www.fromquarkstoquasars.com/how-are-stars-born-how-do-they-die/

Image: NASA, open the image in a new tab to see larger 
A G-type main-sequence star (G V), often (and imprecisely) called a yellow dwarf, or G dwarf star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K. Like other main-sequence stars, a G-type main-sequence star is in the process of converting hydrogen to helium in its core by means of nuclear fusion. The Sun is the best known (and most visible) example of a G-type main-sequence star. Each second, it fuses approximately 600 million tons of hydrogen to helium, converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri A, Tau Ceti, and 51 Pegasi.The term yellow dwarf is a misnomer, as G stars actually range in color from white, for more luminous types like the Sun, to only slightly yellow for the less luminous GV stars. The Sun is in fact white, but appears yellow through the Earth’s atmosphere due to Rayleigh scattering. In addition, although the term “dwarf” is used to contrast yellow main-sequence stars from giant stars, yellow dwarfs like the Sun outshine 90% of the stars in the Galaxy (which are largely orange dwarfs, red dwarfs, and white dwarfs, the latter being a post-main-sequence star).
read more

A G-type main-sequence star (G V), often (and imprecisely) called a yellow dwarf, or G dwarf star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K. Like other main-sequence stars, a G-type main-sequence star is in the process of converting hydrogen to helium in its core by means of nuclear fusion. The Sun is the best known (and most visible) example of a G-type main-sequence star. Each second, it fuses approximately 600 million tons of hydrogen to helium, converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri A, Tau Ceti, and 51 Pegasi.

The term yellow dwarf is a misnomer, as G stars actually range in color from white, for more luminous types like the Sun, to only slightly yellow for the less luminous GV stars. The Sun is in fact white, but appears yellow through the Earth’s atmosphere due to Rayleigh scattering. In addition, although the term “dwarf” is used to contrast yellow main-sequence stars from giant stars, yellow dwarfs like the Sun outshine 90% of the stars in the Galaxy (which are largely orange dwarfs, red dwarfs, and white dwarfs, the latter being a post-main-sequence star).

read more

Why is the Sun called a 3rd generation star?Shortly after the big bang, most of the atoms in the universe were hydrogen. (Trace amounts of helium and lithium, but for all intents and purposes, hydrogen was pretty muc ‘it.’)Those first stars, through fusion, began creating heavier elements, as heavy as iron. Some of those stars were massive enough to “go” supernova, and create even heavier elements.Our sun, and the planets that orbit it, all formed from a nebulous cloud of a star that had previously gone supernova. Based on the amount of heavy elemnts in our solar system, there must have been at least two predecessor stars to have been “precursors” to our sun and it’s planets.The sun, being about 4.5 billion years old, vs. a galaxy that is estimated to be about 13.7 billion years old, seems to have formed in the timespan when 2nd and 3rd generation high-mass stars would have been going supernova. So we have methods that support this statement.
source

Why is the Sun called a 3rd generation star?

Shortly after the big bang, most of the atoms in the universe were hydrogen. (Trace amounts of helium and lithium, but for all intents and purposes, hydrogen was pretty muc ‘it.’)

Those first stars, through fusion, began creating heavier elements, as heavy as iron. Some of those stars were massive enough to “go” supernova, and create even heavier elements.

Our sun, and the planets that orbit it, all formed from a nebulous cloud of a star that had previously gone supernova. Based on the amount of heavy elemnts in our solar system, there must have been at least two predecessor stars to have been “precursors” to our sun and it’s planets.

The sun, being about 4.5 billion years old, vs. a galaxy that is estimated to be about 13.7 billion years old, seems to have formed in the timespan when 2nd and 3rd generation high-mass stars would have been going supernova. So we have methods that support this statement.

source

The Olbers’ Paradox: Why is the Night Sky Dark?Even if have never heard of Olbers’ paradox, you might still be familiar with its basic premise. It basically asks the question, ‘why isn’t the entire night sky as bright as the sun?’ You might be a bit taken back as to why this question is even considered by astronomers, but it isn’t unfounded. Since the universe could extend infinitely in all directions, there might be an infinite number of stars. This means that, no matter where we looked, every point in the sky should shine with light.Ultimately, this is a serious question that may help answer more of the universe’s mysteries; however, this is by no means a modern question. As far back as 1610, individuals were considering this question. Kepler was one of the first to bring this question to light (get the pun), though it wasn’t until the 19th century that Heinrich Wilhelm Olbers popularized it as a paradox. There have been several proposed attempts to solve this mystery, and I’ll run through some of the major ones.Discover why the sky is dark at:http://www.fromquarkstoquasars.com/the-olbers-paradox-why-is-the-night-sky-dark/Image source:http://wanderingowloutside.wordpress.com/2010/11/07/a-winter-project-learning-the-night-skies/
source 

The Olbers’ Paradox: Why is the Night Sky Dark?

Even if have never heard of Olbers’ paradox, you might still be familiar with its basic premise. It basically asks the question, ‘why isn’t the entire night sky as bright as the sun?’ You might be a bit taken back as to why this question is even considered by astronomers, but it isn’t unfounded. Since the universe could extend infinitely in all directions, there might be an infinite number of stars. This means that, no matter where we looked, every point in the sky should shine with light.

Ultimately, this is a serious question that may help answer more of the universe’s mysteries; however, this is by no means a modern question. As far back as 1610, individuals were considering this question. Kepler was one of the first to bring this question to light (get the pun), though it wasn’t until the 19th century that Heinrich Wilhelm Olbers popularized it as a paradox. There have been several proposed attempts to solve this mystery, and I’ll run through some of the major ones.

Discover why the sky is dark at:
http://www.fromquarkstoquasars.com/the-olbers-paradox-why-is-the-night-sky-dark/

Image source:
http://wanderingowloutside.wordpress.com/2010/11/07/a-winter-project-learning-the-night-skies/

source 

The Darkness
Don’t be fooled by the title; the mysterious, almost mystical bright light emerging from these thick, ominous clouds is actually a telltale sign of star formation. Here, a very young star is being born in the guts of the dark cloud LDN 43 — a massive blob of gas, dust, and ices, gathered 520 light-years from Earth in the constellation of Ophiuchus (The Serpent Bearer).
Stars are born from cosmic dust and gas, which floats freely in space until gravity forces it to bind together. The hidden newborn star in this image, revealed only by light reflected onto the plumes of the dark cloud, is named RNO 91. It is what astronomers call a pre-main sequence star, meaning that it has not yet started burning hydrogen in its core.
The energy that allows RNO 91 to shine comes from gravitational contraction. The star is being compressed by its own weight until, at some point, a critical mass will be reached and hydrogen, its main component, will begin to fuse together, releasing huge amounts of energy in the process. This will mark the beginning of adulthood for the star. But even before this happens the adolescent star is bright enough to shine and generate powerful stellar winds, emitting intense X-ray and radio emission.
RNO 91 is a variable star around half the mass of the Sun. Astronomers have been able to observe the existence of a dusty, icy disc surrounding it, stretching out to over 1700 times the distance from Earth to the Sun. It is believed that this disc may host protoplanets — planets in the process of being formed — and will eventually evolve into a fully-fledged planetary system.
This image is based on data gathered by the NASA/ESA Hubble Space Telescope. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.
Image: ESA/Hubble & NASA Acknowledgement: Judy Schmidt 
source

The Darkness

Don’t be fooled by the title; the mysterious, almost mystical bright light emerging from these thick, ominous clouds is actually a telltale sign of star formation. Here, a very young star is being born in the guts of the dark cloud LDN 43 — a massive blob of gas, dust, and ices, gathered 520 light-years from Earth in the constellation of Ophiuchus (The Serpent Bearer).

Stars are born from cosmic dust and gas, which floats freely in space until gravity forces it to bind together. The hidden newborn star in this image, revealed only by light reflected onto the plumes of the dark cloud, is named RNO 91. It is what astronomers call a pre-main sequence star, meaning that it has not yet started burning hydrogen in its core.

The energy that allows RNO 91 to shine comes from gravitational contraction. The star is being compressed by its own weight until, at some point, a critical mass will be reached and hydrogen, its main component, will begin to fuse together, releasing huge amounts of energy in the process. This will mark the beginning of adulthood for the star. But even before this happens the adolescent star is bright enough to shine and generate powerful stellar winds, emitting intense X-ray and radio emission.

RNO 91 is a variable star around half the mass of the Sun. Astronomers have been able to observe the existence of a dusty, icy disc surrounding it, stretching out to over 1700 times the distance from Earth to the Sun. It is believed that this disc may host protoplanets — planets in the process of being formed — and will eventually evolve into a fully-fledged planetary system.

This image is based on data gathered by the NASA/ESA Hubble Space Telescope. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.

Image: ESA/Hubble & NASA Acknowledgement: Judy Schmidt 

source

Life Cycle of a StarStarting on the left (9’o’clock) move clockwise.The difference which causes the splits after the Red Giant (3’o’clock) and Supernova (5’o’clock) is determined by how much mass the star has. Occasionally a supernova will result in another nebula and the process restarts (inner circle, dotted line)
open in a new tab or window to see larger
source

Life Cycle of a Star

Starting on the left (9’o’clock) move clockwise.
The difference which causes the splits after the Red Giant (3’o’clock) and Supernova (5’o’clock) is determined by how much mass the star has. 
Occasionally a supernova will result in another nebula and the process restarts (inner circle, dotted line)

open in a new tab or window to see larger

source