# STARS



## Drone (Mar 12, 2014)

A powerful telescope in Chile has imaged the largest yellow star ever discovered.
The star, called *HR 5171 A*, shines 12000 ly from Earth in the center of a new image released today (March 12). Known as a "yellow hypergiant,"







The star is more than ..... wait for it ...... *1300 times the diameter of the sun*

HR 5171 A is 50% larger than the red supergiant Betelgeuse.

The observations showed that *this star has a very close binary partner*. The two stars are so close that they touch and the whole system resembles a gigantic peanut.

The star shines ~ 1 million times brighter than the sun. Can be spotted with the naked eye.


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## stuartb04 (Mar 12, 2014)

it really does hurt my brain sometimes when i think too deep about the size of 
these stars in comparison to our own.

why is the star yellow at this size though?

maybe it changes colour later on.


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## Drone (Mar 12, 2014)

I agree, Stuart. It's mind blowing. And I agree about the color. Maybe it'll get redder in some million years. We'll have to wait and see lol


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## 15th Warlock (Mar 12, 2014)

How can another star be so close to such a massive star and not collide with it due to the gravitational pull? The universe never ceases to amaze me and humble my limited human reasoning 

Thanks for this most interesting post.


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## remixedcat (Mar 13, 2014)

Feed it some iron


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## xenocide (Mar 17, 2014)

remixedcat said:


> Feed it some iron


 
I would think you would need an amount of pure iron equivalent to the sun to make a dent.



stuartb04 said:


> it really does hurt my brain sometimes when i think too deep about the size of
> these stars in comparison to our own.
> 
> why is the star yellow at this size though?
> ...


 
If I recall the color of a star isn't entirely dependant on the size, but more of the chemical composition (so to speak) of it which affects the rate of fusion within the star.  There are generally speaking, a lot of outliers when it comes to outer space


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## Drone (Mar 17, 2014)

xenocide said:


> If I recall the color of a star isn't entirely dependant on the size, but more of the chemical composition (so to speak) of it which affects the rate of fusion within the star.  There are generally speaking, a lot of outliers when it comes to outer space



Star's colour depends solely on its *temperature* and nothing else. Basically all stars are made of the same stuff.


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## Drone (Nov 19, 2015)

Astronomers used ALMA to study the well-known cool, dim red dwarf star *TVLM 513-46546*, which is located ~ 35 ly from us in the constellation Boötes.

*The star is a mere 10% the mass of the Sun* and is so small and cool that it's right on the dividing line between stars (which fuse hydrogen) and brown dwarfs (which don't). One of the things that make this small star remarkable is that it spins rapidly, *completing a full rotation about every two hours*. Our Sun takes about 25 days to rotate once at its equator. What's more, _this *star exhibits a magnetic field* that rivals the Sun's most extreme magnetic regions and is *several hundred times stronger than the Sun's average magnetic field*_.

When the researchers examined the star with ALMA they detected emission at a particularly high frequency (95 GHz or a wavelength of about 3 mm). Such a radio signal is produced by a process known as *synchrotron emission*, in which electrons zip around powerful magnetic field lines: the more powerful the magnetic field, the higher the frequency.




Radio emission from TVLM 513-46546. The time between each bright pulse corresponds to 1.958 hours, which is the period of rotation of the dwarf.
Astronomers will study similar stars in the future to determine whether this one is an oddball or an example of an entire class of stormy stars.


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## Drone (Feb 19, 2016)

*Gamma Velorum
*
This system contains two stars (30 and 10 Solar Mass). Their orbital parameters are well-studied and they are separated by about the same distance as Earth and Sun. *This binary system is ~ 200 000 times more luminous than the Sun* and strong stellar winds have very high mass loss rate: *10^-5* and *2*10^-7* of a solar mass per year_._ Though these figures seem to be small, actually this amount is huge, particularly comparing to the solar wind which only amounts to *10^-14 solar mass per annum*. As the stellar winds in the Gamma Velorum system collide on a speed exceeding 1000 km/s, particles are accelerated in the shock. Though an exact mechanism of this acceleration is still unknown, it definitely leads to a high energy photon radiation.


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## Drone (Feb 19, 2016)

Star *HD 209458* is similar to our Sun and lies 150 ly from us in the constellation of Pegasus. This star harbors a close-in giant planet that transits across the star's disk.


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## dorsetknob (Feb 19, 2016)

Drone said:


> Basically all stars are made of the same stuff.



 Does this include the ones made from Dark Matter   if they exist 

"Oh and its not a piss take "
  if Enough Dark Matter exists then its possible for enough to accumulate like Normal matter to form a Dark Matter Sun !!!!!


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## Drone (Feb 19, 2016)

dorsetknob said:


> Does this include the ones made from Dark Matter   if they exist
> 
> "Oh and its not a piss take "
> if Enough Dark Matter exists then its possible for enough to accumulate like Normal matter to form a Dark Matter Sun !!!!!




Yes and that's a really interesting question/theory. I remember the articles and I even have original links in my bookmarks:

http://www.nature.com/news/physicists-see-potential-dark-matter-from-the-sun-1.16174
http://physicsworld.com/cws/article...ld-the-sun-be-trapping-asymmetric-dark-matter
https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.114.081302

Unfortunately it's still unknown whether our Sun (and other stars) contain dark matter within their cores.


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## Drone (Feb 19, 2016)

Illustration depicting gravitational capture (black arrows) of dark matter as the Sun passes through the galactic halo and outward heat transport inside the Sun (yellow arrows). (Courtesy: Aaron Vincent, Durham University)








And here's another interesting article

http://www-sk.icrr.u-tokyo.ac.jp/whatsnew/2015/04/10/solarwimp-e.html


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## Drone (Feb 28, 2016)

Cygnus X-1 is ~ 10 000 ly years from Earth and one of the brightest high-energy emitters in the sky. It was discovered in the 1960s and is thought to be a black hole, ripping its companion star to pieces. The companion star, HDE 226868, is a blue supergiant with a surface temperature of ~ 31 000K. It orbits the black hole once every 5.6 days.


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## Drone (Feb 29, 2016)

Emission-line star *IRAS 12196-6300*.

Located just under 2300 ly from Earth, this star displays prominent emission lines. Under 10 million years old and not yet burning hydrogen at its core this star is still in its infancy. Further evidence of IRAS 12196-6300's youth is provided by the presence of reflection nebulae. These hazy clouds, pictured floating above and below IRAS 12196-6300, are created when light from a star reflects off a high concentration of nearby dust, such as the dusty material still remaining from IRAS 12196-6300's formation.


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## Drone (Mar 3, 2016)

Researchers using ALMA have observed late-phase protostar named TMC-1A located 450 ly away from us, in the constellation Taurus. The mass of the baby star is 0.68 times the mass of the Sun.






Dense gas seen around the baby star is shown in red. Outflowing gas is shown in white. The position of the star is indicated with a cross.

*Stars form in dense gas clouds. Baby stars grow by taking in the surrounding gas. In this process, gas cannot flow directly into the star. Instead it first accumulates and forms a disk around the star, and then the disk feeds into the star.
*
*



*​Gas motion around TMC-1A. The red color indicates gas is moving away from us while the blue color is coming closer to us.

*Gas is infalling to the disk from the envelope further out*. Astronomers found that the boundary between the disk and envelope is located 90 AU (3 times longer than the orbit of Neptune) from the central baby star. _As the baby star grows, the boundary between the disk and the infall region moves outward.

The gas infall rate to be a millionth of the mass of the Sun per year, with a speed of 1 km/s. Gravity causes gas to fall towards the central baby star, but the measured speed is much less than the free-fall speed. Something must be slowing the gas down. The researchers suspect that a magnetic field around the baby star might be what is slowing the gas.

_


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## Drone (Mar 5, 2016)

Nostalgic photos:






Star called* CoRoT-2a* is blasting a planet in its orbit with an extremely high level of X-rays. This high-energy radiation is eroding the planet at a rate of 5 million tons of material per second. The planet, in turn, may be speeding up the star's rotation, which keeps the star's magnetic fields very active. This system is ~ 880 ly from Earth and it's 100-300 million years old.  The separation between the star and the planet is only 3% of the distance between the Earth and the Sun (AU).






The star *CoRoT-7* is located towards the constellation of Monoceros at a distance of ~ 500 ly. Slightly smaller and cooler than our Sun, CoRoT-7 is also thought to be younger, with an age ~ 1.5 billion years. *It's now known to have two planets*, one of them being the first to be found with a density similar to that of Earth. CoRoT-7 is in the center of the image.


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## Drone (Mar 5, 2016)

The image on the left from NASA's Chandra X-ray Observatory shows the first _double-sided X-ray jet_ ever detected from a young star, named *DG Tau*. A similar jet may have been launched from the young Sun and could have had a significant impact on the early solar system.

DG Tau is located in the Taurus star-forming region, ~ 450 ly from us. The bright source of X-rays in the middle of the image is DG Tau and the jet runs from the top left to the bottom right, extending to about 70 billion miles away (~ 700 AU) from the star.

DG Tau has about the same mass as the Sun, but is much younger with an age of about one million years. X-ray irradiation of disks may be important in the production of complex molecules in the disk that will later end up on the forming planets.


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## Drone (Mar 9, 2016)

*The Very Large Telescope Interferometer at ESO's Paranal Observatory in Chile has obtained the sharpest view ever of the dusty disc around an aging star.
*
This is so cool that I almost peed my pants lol 






Their target was the old double star IRAS 08544-4431, lying ~ 4000 ly from Earth in the southern constellation of Vela. This double star consists of a red giant star, which expelled the material in the surrounding dusty disc, and a less-evolved more normal star orbiting close to it.

The most prominent feature of the image is the _clearly resolved ring_.

The team finds that discs around old stars are indeed very similar to the planet-forming ones around young stars. Whether a second crop of planets can really form around these old stars is yet to be determined, but it is an _intriguing possibility_.


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## Drone (Mar 16, 2016)

VY Canis Majoris in Polarized and Visible light











*VY Canis Majoris*, also known as VY CMa, HD 58061 or HIP 35793, is a red hypergiant located in the constellation Canis Major.

This star is 3840 ly distant from Earth and is one of the largest known stars.

According to astronomers, *VY Canis Majoris has a radius of approximately 1420 solar radii. It is about 35 times the mass of our Sun and 300 000 times more luminous.*

*VY Canis Majoris sees 30 times the mass of Earth expelled from its surface in the form of dust and gas every year*. Analysis of the polarization results revealed these particles to be comparatively large particles, 0.5 micrometers across, which may seem small, but grains of this size are about 50 times larger than the dust normally found in interstellar space. These are big enough to be pushed away by the star's intense radiation pressure, which explains the star's rapid mass loss.


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## Frick (Mar 16, 2016)

The top image of CMa looks so awesome on my phone. I desperately want a high res version for my desktop.


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## Drone (Mar 17, 2016)

I really hope that nextgen telescopes will provide sharper images of VY Cma and Kappa Ceti. BTW forgot to add this old article:

Detection of two titanium oxides around the giant star VY Canis Majoris



> The observations of TiO and TiO2 show that the two molecules are easily formed around VY CMa at a location that is more or less as predicted by theory. It seems, however, that some portion of those molecules avoid forming dust and are observable as gas phase species. Another possibility is that the dust is destroyed in the nebula and releases fresh TiO molecules back to the gas. The latter scenario is quite likely as parts of the wind in VY CMa seem to collide with each other.




Another interesting star:

*Kappa Ceti*​
*




*​
Kappa Ceti located 30 ly away in the constellation Cetus, is *remarkably similar to our Sun* but younger. It's only 400-600 million years old.

Like other stars its age, Kappa Ceti is *very magnetically active*. Its surface is blotched with many giant *starspots*. It also propels a *steady stream of plasma* out into space. This stellar wind is *50 times stronger* than our Sun's solar wind.

Kappa Ceti also shows evidence of "*superflares*" that release _10 to 100 million times more energy than the largest flares ever observed on our Sun_. Flares that energetic can strip a planet's atmosphere.


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## Drone (Mar 17, 2016)

Astronomers used the VLA to see unprecedented detail of the inner portion of a dusty disk surrounding the star, called *HL Tau*, some 450 ly from us.

_*HL Tau is only about a million years old - very young by stellar standards.*_

The ALMA image showed details of the system in the outer portions of the disk, but in the inner portions of the disk, nearest to the young star, the thicker dust is opaque to the short radio wavelengths received by ALMA. To study this region, astronomers turned to the VLA, which receives longer wavelengths. Their VLA images show that region better than any previous studies.

The new VLA images revealed a *distinct clump of dust in the inner region of the disk*. The clump contains roughly 3-8 times the mass of the Earth.

Analysis of the VLA data indicates that the inner region of the disk contains grains as large as 1cm in diameter. This region is presumably where Earth-like planets would form, as clumps of dust grow by pulling in material from their surroundings. Eventually, the clumps would gather enough mass to form solid bodies that would continue to grow into planets.


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## Drone (Mar 17, 2016)

Astronomers using the unique UV capabilities of Hubble Space Telescope have identified 'monster' stars in the star cluster R136.

R136 is only a few ly across and is located in the Tarantula Nebula within the Large Magellanic Cloud, ~ 170 000 ly away. The young cluster hosts many _extremely massive_, hot and luminous stars whose energy is mostly radiated in the UV.




This new study was able to reveal* 9 very massive stars in the cluster, all > 100 times more massive as the Sun*. The detected stars are not only extremely massive, but also extremely bright. *Together these 9 stars outshine the Sun by a factor of 30 million*.

The scientists were also able to investigate outflows from these behemoths. *They eject up to an Earth mass of material per month at a speed approaching 1% of the speed of light, resulting in extreme weight loss throughout their brief lives*.


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## Drone (Mar 19, 2016)

This false-color near-infrared image has been processed to remove most of the scattered light from the star Kappa Andromedae (masked out at center). The "super-Jupiter" companion, Kappa Andromedae b (upper left), lies at a projected distance of about 55 AU or about 1.8 times farther than Neptune, whose orbit is shown for comparison (dashed circle). The white region marking the companion indicates a signal present in all near-infrared wavelengths, while colored blobs represent residual noise.






Scientists focused on the star Kappa Andromedae because of its relative youth - estimated at the tender age of 30 million years, or just 0.7% the age of our Sun, based on its likely membership in a stellar group known as the Columba Association. The B9-type star is located 170 ly away in the direction of the constellation Andromeda and is visible to the unaided eye.

Exoplanet *Kappa Andromedae b* has a mass ~ 12.8 times greater than Jupiter's. It has a temperature of ~ 1400 Celsius and would appear bright red if seen up close by the human eye.


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## Drone (Mar 22, 2016)

The brilliant flash of an exploding star's shockwave [*shock breakout*] has been captured for the first time in visible light by NASA's Kepler Space Telescope.

Scientists analyzed light captured by Kepler every 30 minutes over a three-year period from 500 distant galaxies, searching some 50 trillion stars.

2 of these massive stars exploded while in Kepler's view. The first behemoth, *KSN 2011a*, is nearly _300 times the size of our sun and a mere 700 million ly from Earth_. The second, *KSN 2011d*, is roughly _500 times the size of our sun and around 1.2 billion ly away_. Supernovae like these are known as *Type II*.







​The explosive death of a star, called KSN 2011d, as it reaches its maximum brightness takes 14 days. The shock breakout itself lasts only about 20 minutes. This type of star is called a _red supergiant_ star and it's 20 000 times brighter than our sun. As the supergiant star goes supernova, the energy traveling from the core reaches the surface with a burst of light that is 130 million times brighter than the sun. The star continues to explode and grow reaching maximum brightness that is about 1 billion times brighter than the sun.


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## Drone (Mar 23, 2016)

Supernova 2012cg

Located 50 million ly away in the constellation Virgo, the supernova is blowing up next to a companion star, and the explosion impacts the companion star. The side of that companion star that's hit gets hot and bright. The excess blue light is coming from the side of the companion star that gets heated up.

Combined with the models, the observations indicate that the binary companion star has a minimum mass of six suns.


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## Drone (Mar 24, 2016)

​The yellow-orange host galaxy (left) before the supernova, and afterwards (right) when the *ASASSN-15lh* super-luminous supernova's blue light outshines its host galaxy.

ASASSN-15lh, was discovered in 2015 and is possibly the most luminous and powerful explosion ever seen, more than 500 times brighter than normal supernovae. *For more than a month its luminosity was 20 times brighter than the whole Milky Way galaxy*.


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## Drone (Apr 2, 2016)

Astronomers discover white dwarf star with an* atmosphere completely dominated by oxygen *SDSS J124043.01+671034.68 (SDSS J1240+6710 for short).






Stars born with masses ≤ 8-11 solar masses end their lives as small, hot, and extremely dense objects known as white dwarfs. Their atmospheres are dominated by the lightest elements, such as hydrogen or helium, because _gravitational diffusion brings the lightest element to the surface_.

Scientists identified oxygen-neon white dwarf SDSS J1240+6710 with its outer layer of light elements stripped away, revealing a nearly pure layer of oxygen.

Oxygen, neon, and magnesium are the products of carbon burning, which occurs in stars at the high-mass end of pre-white dwarf formation. SDSS J1240+6710 has a mass of 0.56 solar masses and is located 1174 ly away.
*
One possibility is that interactions with a nearby companion in a binary star caused this unique star to bare its oxygen envelope.

Another possibility is that a massive pulse of burning carbon from the center of the star, emanating outwards, eliminated the lighter elements.
*


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## Drone (Apr 13, 2016)

This is so mysterious exciting magnificent and simply mind blowing that I can hardly breath ... 


PB3877 is a *hyper-velocity wide binary star* zooming through the outskirts of the Milky Way. This binary star is moving nearly at the escape velocity of our galaxy.

The surface of the hot compact star is > 5 times hotter than the Sun, while the companion is a thousand degrees cooler than our Sun. The system was determined to be 18 000 ly away. The mass of the hot compact star is .5 times the mass of our Sun, and the companion is .7 times the mass of the Sun.










PB3877 could be an *intruder that has been born in another galaxy* and may or may not leave the Milky Way again.


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## Drone (Apr 23, 2016)

My favorite star - *Alpha Virginis* (Spica)




Alpha Virginis is the 15th brightest star in the night sky, in part because it is relatively nearby, only ~ 250 ly away. Spica is a "spectroscopic" binary, two stars orbiting each other and too close together to separate visually. The stars in Spica are, moreover, an unusual pair: They are very close, separated by ~ 28 solar-radii, and orbit each other in only 4.01 days. This puts them _so close together that their mutual gravity tidally distorts their atmospheres_, with the result that the stars are not spherical. Oh, and the more massive star pulses in size and luminosity. Spica's two stars are both massive, at 11.4 and 7.2 solar-masses, respectively.


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## Caring1 (Apr 23, 2016)

That might get messy if and when they collide.


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## Drone (May 4, 2016)

By using multiple telescopes, scientists were able to get one of the best maps ever of a star other than the Sun.





A star like the Sun has an internal driving in the form of a magnetic field that can be seen on the surface as sunspots. Now astrophysicists from the Niels Bohr Institute have observed a distant star *ζ Andromedae* with a different positioning of sunspots and this indicates a magnetic field that is driven by completely different internal dynamics.

Stars are glowing balls of gas that through atomic processes release energy that is emitted as light and heat. In the interior of the star are charged particles that swirl and spin and thereby create a magnetic field that can burst out onto the surface of the star, where it appears as starspots. Starspots are cool areas caused by the strong magnetic fields where the flow of heat is slowed. _On the Sun the sunspots are seen in a belt around the equator_, but now scientists have observed a _large, distant star where sunspots are located near the poles_.

ζ Andromedae is an old active massive star that is ~ 16 times the size of the Sun in diameter. It's located 180 ly away. It's part of a binary star system, causing the stars to rotate more quickly. The larger of the two stars, rotates at 40 km/s. The Sun rotates at 2 km/s.


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## Drone (May 5, 2016)

More info on Zeta Andromedae (aka HD 4502) and pics:


















http://www.sci-news.com/astronomy/zeta-andromedae-surface-images-03841.html
http://ns.umich.edu/new/releases/23792-starspot-images-give-insights-into-early-sun

ζ Andromedae is a tidally locked close binary system consisting of an orange K-type giant star and an unseen lower-mass companion star.


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## Drone (Jul 15, 2016)

ALMA Observes First Protoplanetary Water Snow Line Thanks to Stellar Outburst






*********






The upper right image shows *Polaris A* and its distant companion *Polaris B*, as viewed by Hubble. They are separated by ~ 240 billion miles. Polaris B, the wide companion, is visible in small telescopes, and was first noticed by William Herschel in 1780. The close companion, *Polaris Ab* was known to exist from its gravitational tug on Polaris A, but has only been seen directly now using Hubble (lower right image). The companion is only 2 billion miles from Polaris A.

The triple system is 430 ly away.


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## Drone (Aug 7, 2016)

Star Size Comparison 2


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## Caring1 (Aug 7, 2016)

Holy shite, way to make us feel insignificant 
I hope my other self in another multiverse realises one of us is going to die before the other, and we'll never know which one, or perhaps we all die simultaneously.


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## hat (Aug 7, 2016)

The only thing it takes to make me feel insignificant is to look around, not even towards the heavens. Of course, it remains true that the more upward you look, the more insignificant you and even your surroundings appear...


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## Drone (Aug 15, 2016)

Resembling the puffs of smoke and sparks from a summer fireworks display, this Hubble image depicts the delicate filaments debris from a stellar explosion in a neighboring galaxy.

N 49, or DEM L 190 is a supernova remnant whose light would have reached Earth thousands of years ago. This filamentary material will eventually be recycled into building new generations of stars. Our own sun and planets are constructed from similar debris of supernovae that exploded in the Milky Way billions of years ago.

This seemingly gentle structure also harbors a very powerful spinning neutron star that may be the central remnant from the initial blast. It is quite common for the core of an exploded supernova star to become a spinning neutron star (pulsar) after the immediate shedding of the star's outer layers. In the case of N 49, not only is the neutron star spinning at a rate of once every 8 seconds, it also has a *super-strong magnetic field a quadrillion times stronger than Earth's magnetic field*. This places this star into the exclusive class of objects called *magnetars*.


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## Drone (Aug 18, 2016)

Bright star named *Hen 2-427* (otherwise known as WR 124).

It's a Wolf-Rayet star, a rare type of star known to have very high surface temperatures – well over 25 000ºC, next to the Sun's comparatively cool 5500ºC – and enormous mass, which ranges over 5-20 times our Sun's. Such stars are constantly losing vast amounts of mass via thick winds that continuously pour from their surfaces out into space.






A new image of supernova remnant *G11.2-0.3* is being released in conjunction with this week's workshop titled "Chandra Science for the Next Decade" being held in Cambridge, Massachusetts.

The supernova explosion produced a pulsar - a rapidly rotating neutron star - and a pulsar wind nebula, shown by the blue X-ray emission in the center of the remnant. The combination of the pulsar's rapid rotation and strong magnetic field generates an intense electromagnetic field that creates jets of matter and anti-matter moving away from the north and south poles of the pulsar, and an intense wind flowing out along its equator.

•New Chandra data raise new questions about the timing of its origin.

•Previously, G11.2-0.3 was associated with an event recorded by Chinese observers in 386 CE.

•Chandra observations show that dense gas clouds lie along the line of sight between Earth and G11.2-0.3.

•This new information means that the supernova explosion would have been too faint to be seen with the naked eye from Earth.

•This leaves the nature of the observed 386 CE event a mystery.


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## Drone (Aug 23, 2016)

Brilliant vids


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## Drone (Aug 24, 2016)

New images by ESA:







This image of the sky around the bright star *Alpha Centauri AB* also shows the much fainter red dwarf star, *Proxima Centauri*, the closest star to the Solar System. The picture was created from pictures forming part of the Digitized Sky Survey 2. The blue halo around Alpha Centauri AB is an artifact of the photographic process, the star is really pale yellow in color like our Sun. (Download original image 714 MB)







The relative sizes of a number of objects, including the three (known) members of Alpha Centauri triple system and some other stars. Sun and Jupiter are also shown for comparison.


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## Drone (Aug 28, 2016)

Dying star IRC+10216 is surrounded by a large volume of high-temperature water vapor.

A swollen red giant star is having the final, spectacular party of its life. If it weren't for these dying stars _ enriching _ the chemistry of the matter in the galaxy, there would be no rocky planets and no life.


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## Drone (Aug 30, 2016)

An age-defying star designated as *IRAS 19312+1950* exhibits features characteristic of a very young star and a very old star. The object stands out as extremely bright inside a large, chemically rich cloud of material, as shown in this image from NASA's Spitzer Space Telescope. A NASA-led team of scientists thinks the star – which is ~ 10 times as massive as our sun and emits about 20000 times as much energy – is a newly forming protostar.

Scientists found large quantities of ices made from water and carbon dioxide in the cloud around the object. These ices are located on dust grains relatively close to the star, and all this dust and ice blocks out starlight making the star seem dimmer than it really is.


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## Drone (Sep 3, 2016)

*Eta Carinae* is a celebrity among objects in the Universe. An hourglass-shaped, billowing cloud of glowing gas and dust enshrouds the star and its companion. Known as the *Homunculus* nebula, the cloud consists of stellar material hurled into space during the *Great Eruption* (19th-century brightening).

This animated view of Hubble Space Telescope images taken between 1993 and 2014 reveals how much the mass ejections from Eta Carinae have moved outward into space, some at a speed of 2 million mph.






The expansion rate of gas that was far outside the Homunculus indicated that it was moving slowly and must have been ejected centuries before the Great Eruption. In fact, the motions of the outer material point to two separate eruptions in the mid-13th and mid-16th centuries.


Eta Carinae is a binary system located 7000 ly away. Two very massive stars orbit each other every 5.5 years. Both are much bigger than our sun and at least one of them is nearing the end of its life. These are very large stars that appear very volatile, even when they're not blowing off nebulae. They have a dense core and very fluffy envelopes. If you replaced our sun by the larger of the two, which has ~ 90-100 solar masses, it could very well extend into the orbit of Mars.


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## Drone (Sep 6, 2016)

Brown Dwarfs and Quark Novae explained.


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## dont whant to set it"' (Sep 7, 2016)

Second video nu mai este disponibil(no longer available)


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## EarthDog (Sep 7, 2016)

WOrks for me.


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## Drone (Sep 8, 2016)

dont whant to set it"' said:


> Second video nu mai este disponibil(no longer available)


You mean quark nova video? Here's other video by physicsworld where the author himself explains it. Sound quality isn't really good but it's audible and provides thorough scientific explanation.












Short and nice videos by science & u

Dr. Emily Rice explains where the term "nebula" comes from and what it is used to define.










Dr. Emily Rice explains what a Brown Dwarf is and how it differs from other stars.


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## Drone (Sep 9, 2016)

For decades, astronomers have known there is a dense, compact source at the center of RCW 103 - supernova remnant located ~ 9000 ly from us.

RCW 103's central source, known officially as _*1E 1613*48-5055_ is a *young magnetar* (~ 2000 years old). It's rotating once every 24000 seconds (6.67 hours), much slower than the slowest magnetars known until now, which spin around once every 10 seconds. This would make 1E 1613 the *slowest spinning neutron star ever detected*.

While it's still unclear why 1E 1613 is spinning so slowly, scientists do have some ideas. One leading scenario is that *debris from the exploded star has fallen back onto magnetic field lines around the spinning neutron star, causing it to spin more slowly with time*. Searches are currently being made for other very slowly spinning magnetars to study this idea in more detail.


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## Drone (Sep 12, 2016)

The newly launched *ESA Star Mapper* allows users to explore the *3D distribution of almost 60 000 stars* from the Hipparcos Catalogue. Stars are visualised as a function of their brightness; it's also possible to show their colors, as well as names and parent constellations for the brightest stars.

Users can get a sense of where in the sky stars were located in the past – or will be in the future – based on their motions.

A visualisation of the 'Hertzsprung-Russell diagram', a tool used by astronomers to study the evolution of stars, is provided as well.


Just click here

  I'm running out of emotions


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## BiggieShady (Sep 12, 2016)

In the same vein, this one comes with a tour ... mute button is in upper right corner: http://stars.chromeexperiments.com/


... and weirdly google sky is still up: https://www.google.com/sky/

oh, and I love this one http://server3.sky-map.org/v2


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## Drone (Sep 13, 2016)

This animation shows the fast evolution of *SAO 244567*. The animation starts 10 300 BC, with the star having a radius 152 times the size of the Sun and a surface temperature of ~ 3500 degree Celsius, giving it its orange color. At this point of its life the star had already lost half of its initial mass.

After 10 000 years the star slowly shrinks to only 40 times the size of the Sun; at the same time its temperature rises to 6800 degree Celsius, causing its color to change to white-yellow. As the star heats up to ~  20 000 degree Celsius Helium fusion inside the star suddenly gets re-ignited — the late thermal pulse.

After the flash the star heats quickly and becomes a blue-white star with a temperature of 21 000 degree Celsius, only 4 times larger than the Sun. SAO 244567 shrinks further till it only a third the size of the Sun and a temperature of 60 000 degree Celsius; this status was reached in the year 2002. Now new observations show that the star is still blue and hot — with ~ 50 000 degree Celsius — but started to expand again: its size is ~ two third of our Sun.

Within the next few hundreds of years SAO 244567 will expand back to its giant dimensions and also change its color to orange — as shown at the end of the animation.


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## Drone (Sep 14, 2016)

The first catalogue of > *1 billion stars* from ESA's Gaia satellite was published today – *the largest all-sky survey of celestial objects to date*.

On its way to assembling the most detailed 3D map ever made of our Milky Way galaxy, Gaia has pinned down the *precise position on the sky and the brightness of 1142 million stars*.










ONE. BILLION. STARS.


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## Drone (Oct 11, 2016)

Nebula PK 329-02.2 (aka Menzel 2)

Two bright blue spiral arms perfectly align with the two stars at the center.

It may look like the spiral arms are connected, but it is the stars that are companions. They are part of a visual binary, though only the one at the upper right gave rise to the nebula. While the stars will continue to orbit each other for millions or billions of years, the nebula – and its spiral arms – will spread out from the center and eventually fade away over the next few thousands of years.


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## Drone (Oct 19, 2016)

Highest Resolution Image of Eta Carinae






Astronomers found new and unexpected structures within the binary system, including in the area between the two stars where extremely high velocity stellar winds are colliding.


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## Drone (Oct 27, 2016)

ALMA image of the *L1448 IRS3B* system, with two young stars at the center and a third distant from them.

This young triple-star system is located in a cloud of gas in the constellation Perseus, some _750 ly_ from us. The most central of the young stars is separated from the other two by _61 and 183 AU_. All three are surrounded by a _disk of material_ that ALMA revealed to have _spiral structure_, a feature that indicates _ instability in the disk_. This whole system probably is < 150000 years old.






Artist's conception of how the triple-star system develops. Left, disk of material fragments into separate protostars. Right, the resulting stellar system.


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## Drone (Oct 30, 2016)

Zooming in on the red giant star L2 Puppis


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## Drone (Nov 9, 2016)

Using the ESO's SPHERE instrument at the Very Large Telescope, a team of astronomers observed the _planetary disc_ surrounding the star *HD 135344B*, ~ 450 ly away. The disc shows _prominent spiral arm-like structures_. These are thought to have been created by one or multiple *massive protoplanets*, destined to become Jupiter-like worlds. The central part of the image appears dark because SPHERE blocks out the light from the brilliant central star to reveal the much fainter structures surrounding it.


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## Drone (Nov 30, 2016)

This wide field image shows the sky around the very faint isolated neutron star *RX J1856.5-3754* in the southern constellation of Corona Australis. This part of the sky also contains interesting regions of dark and bright nebulosity surrounding the variable star R Coronae Australis (upper left), as well as the globular star cluster NGC 6723. The neutron star itself is too faint to be seen here, but lies very close to the center of the image.


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## Drone (Dec 6, 2016)

Dust disk around the young star HD 142527 observed with ALMA

*HD 142527* is located 500 ly away from Earth, in the direction of the constellation Lupus, the Wolf. The age of the star is estimated to be 5 million years old and its mass twice that of the Sun.






ALMA is really powerful.  Just think about it, we can see dust disk around a star which is 500 ly away


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## Drone (Dec 20, 2016)

*Betelgeuse ate a companion star* 100000 years ago?

In a word: perhaps.


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## Drone (Feb 24, 2017)

30 years ago, astronomers spotted one of the brightest exploding stars in more than 400 years. The titanic supernova, called *Supernova 1987A* (SN 1987A), blazed with the power of *100 million suns* for several months following its discovery on Feb. 23, 1987.


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## Drone (Mar 12, 2017)

Zooming in on the star Tau Boötis


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## Drone (Mar 18, 2017)




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## Drone (Mar 21, 2017)

A star explodes: The story of supernova 1987A


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## infrared (Mar 22, 2017)

Cool thread! Cheers for posting all the vids, Drone 
Subscribed!


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## Drone (Mar 23, 2017)




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## Drone (Mar 24, 2017)




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## Drone (Apr 3, 2017)

ALMA's image depicts the dusty disc encircling the young, isolated star *HD 169142*. Observing such dusty protoplanetary discs with ALMA allows scientists to investigate the first steps of planet formation in a bid to unveil the evolutionary paths of these infant systems.


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## Drone (Apr 7, 2017)

*ALMA Captures Dramatic Stellar Fireworks*​


















The new ALMA images showcase the explosive nature in high resolution, unveiling important details about the distribution and high-velocity motion of the carbon monoxide (CO) gas inside the streamers. This will help astronomers understand the underlying force of the blast, and what impact such events could have on star formation across the galaxy.


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## Drone (Apr 11, 2017)




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## Drone (Apr 12, 2017)




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## Drone (May 4, 2017)




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## Drone (Mar 7, 2018)

New hypothetical types of Stars

Quasi Stars; Quark Stars; Electroweak Stars;


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## Drone (Jul 31, 2018)




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## Drone (Nov 20, 2018)




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## MrGenius (Nov 25, 2018)

13.53 billion year old red dwarf star(2MASS J18082002-5104378 B), in our own galaxy, is possibly the oldest star in the Universe.








http://www.sci-news.com/astronomy/ultra-metal-poor-star-06577.html


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## Drone (Dec 28, 2019)




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## Drone (Dec 30, 2019)




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## Drone (Jan 31, 2020)

Space-warping star system proves Einstein's general theory of relativity right


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## lexluthermiester (Jan 31, 2020)

Drone said:


> Space-warping star system proves Einstein's general theory of relativity right


Except that it doesn't. It only proves that the gravity effect of a mass object is warping space, which we already knew from observations(black holes anyone?). Proving General and Special relativity is another matter entirely(pun intended).


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## Drone (Jan 31, 2020)

lexluthermiester said:


> Except that it doesn't. It only proves that the gravity effect of a mass object is warping space, which we already knew from observations(black holes anyone?). Proving General and Special relativity is another matter entirely(pun intended).


No. It's not warping. It's called frame-dragging. This is the first observational evidence of white dwarf + pulsar pair frame-dragging. Frame-dragging caused by black hole will be detected in the future.


> In the case of stars orbiting close to a spinning, supermassive black hole, frame dragging should cause the star's orbital plane to precess about the black hole spin axis. This effect should be detectable within the next few years via astrometric monitoring of stars at the center of the Milky Way galaxy.


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## lexluthermiester (Jan 31, 2020)

Drone said:


> No. It's not warping. It's called frame-dragging.


We can call it whatever we desire, it's still only a mass/gravity object distorting the space around it. While this might be the first occurrence where we have identified what we have observed, it doesn't prove the fundamentals of Relativity, either mathematically or in theory. It does offer a fascinating piece of the puzzle, but it's not a keystone.


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## Countryside (Jan 31, 2020)

Startalk with my favourite astrophysicist Neil deGrasse Tyson and comic co-host Paul Mecurio


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## lexluthermiester (Jan 31, 2020)

Here's a good one;








Kinda short, but very fasinating.


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## EarthDog (Jan 31, 2020)

lexluthermiester said:


> Kinda short, but very _fasinating_.


Fascinating, indeed.

I saw this a couple of days back... I had a still as my wallpaper, but... messed with my head, lol!


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## Antykain (Feb 1, 2020)

Here is another vid showcasing the Inouye Solar Telescope and it's first images of the Sun.. 










Pretty amazing stuff!


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## Drone (Feb 5, 2020)

Stellar fight


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## Drone (Feb 14, 2020)

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed.


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## Drone (Feb 20, 2020)




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## Drone (Mar 9, 2020)




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## Drone (Aug 10, 2020)

R136a1 is the most massive and luminous star known to date [at 315 M☉ and 8.7 million L☉]










UY Scuti is no longer the champion of the known universe. The largest star in the universe now is *Stephenson 2-18*


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## Drone (Sep 24, 2020)




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## Drone (Oct 18, 2020)

New info on Betelgeuse:









						Supergiant Betelgeuse smaller, closer than first thought
					

It may be another 100,000 years until the giant red star Betelgeuse dies in a fiery explosion, according to a new study by an international team of researchers. The study, led by Dr Meridith Joyce from The Australian National University (ANU), not only gives Betelgeuse a new lease on life, but...




					www.anu.edu.au
				




Supergiant Betelgeuse smaller, closer than first thought. It may be another 100k years until the giant explodes.
New results say Betelgeuse's radius is 750 times the radius of the Sun and distance from Earth = 530 ly.


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## Drone (May 3, 2021)




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## Drone (Aug 14, 2021)




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## Drone (Sep 8, 2021)

A Black Hole Triggers a Premature Supernova | www.caltech.edu



















Teardrop star reveals hidden supernova doom (warwick.ac.uk)


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