I Realized Why The Idea Of Constellations Has Always Swayed Me. Constellations Are So Very Human.

Beware of the Big, Bad Wolf

Visible within the center of the Crescent nebula is what’s classified as a Wolf-Rayet star. This star is a staggering 250,000 times brighter than the Sun, 15 times more massive, and 3.3 times larger. Its surface temperature is nearly 70,000° C/ 125,000° F. At just 4.7 million years old, it is already toward the end of it’s life and is shedding its outer envelope, ejecting the equivalent of the Sun’s mass every 10,000 years. Within a few hundred thousand years, it is expected to explode as a supernova.   (Image Credit: Michael Miller, Jimmy Walker)

Sunset from the International Space Station, taken by Scott Kelly

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stars, mercury, and solar corona, photographed by stereo a, january 2009.

27 frames, photographed over 36 hours, 2nd-3rd january. the sun is out of frame right.

image credit: nasa/stereo. animation: ageofdestruction.

If you were on the moon during a lunar eclipse and you looked back at the Earth, you would see it surrounded by the red ring of the sun behind it. You’d be looking at every sunset and every sunrise on Earth at the same time.

Edge-on Spiral Galaxy

New awesome edge-on view of the galaxy NGC 1055 captured by ESO’s Very Large Telescope. This large galaxy is thought to be up to 15 percent larger in diameter than the Milky Way but shares the characteristic spiral arms. (Credit: ESO)

Atmospheric Jellyfish are described as jellyfish-like creature seen floating in the Earth’s atmosphere. Atmospheric Jellyfish are said to look like normal jellyfish except they are floating in the sky much like a cloud and are seen mostly around military bases. Skeptics believe that the Atmospheric Jellyfish could be misidentified clouds or weather balloons however believers hold true to the idea and remember the time that NASA sent 60,000 jellyfish into space during their From Undersea to Outer Space experiment.

The icy blue wings of Hen 2-437

The patterns and symmetries in space never cease to amaze. Hen 2-437 is a planetary nebula which has spectacularly symmetrical wings. It was first identified in 1946 by Rudolph Minkowski, who later also discovered the famous and equally beautiful M2-9, otherwise known as the Twin Jet Nebula:

Hen 2-437 was added to a catalogue of planetary nebula over two decades later by astronomer and NASA astronaut Karl Gordon Henize. If you’re interested in how planetary nebulae form, go here

Credit: ESA/Hubble & NASA

- Carl Sagan, Cosmos: A Spacetime Odyssey

A Blue Bridge of Stars between Cluster Galaxies designated SDSS J1531+3414

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Stellar Winds

Stellar winds are fast moving flows of material (protons, electrons and atoms of heavier metals) that are ejected from stars. These winds are characterised by a continuous outflow of material moving at speeds anywhere between 20 and 2,000 km/s.

In the case of the Sun, the wind ‘blows’ at a speed of 200 to 300 km/s from quiet regions, and 700 km/s from coronal holes and active regions.

The causes, ejection rates and speeds of stellar winds vary with the mass of the star. In relatively cool, low-mass stars such as the Sun, the wind is caused by the extremely high temperature (millions of degrees Kelvin) of the corona.

his high temperature is thought to be the result of interactions between magnetic fields at the star’s surface, and gives the coronal gas sufficient energy to escape the gravitational attraction of the star as a wind. Stars of this type eject only a tiny fraction of their mass per year as a stellar wind (for example, only 1 part in 1014 of the Sun’s mass is ejected in this way each year), but this still represents losses of millions of tonnes of material each second. Even over their entire lifetime, stars like our Sun lose only a tiny fraction of 1% of their mass through stellar winds.

In contrast, hot, massive stars can produce stellar winds a billion times stronger than those of low-mass stars. Over their short lifetimes, they can eject many solar masses (perhaps up to 50% of their initial mass) of material in the form of 2,000 km/sec winds.

These stellar winds are driven directly by the radiation pressure from photons escaping the star. In some cases, high-mass stars can eject virtually all of their outer envelopes in winds. The result is a Wolf-Rayet star.

Stellar winds play an important part in the chemical evolution of the Universe, as they carry dust and metals back into the interstellar medium where they will be incorporated into the next generation of stars. 

source (read more) + Wolf–Rayet star