Astrophysicist Dr. Neil DeGrasse Tyson was asked by a reader of TIME magazine, "What is the most astounding fact you can share with us about the Universe?" This is his answer.
http://youtu.be/9D05ej8u-gU
http://vimeo.com/38101676
Watch the documentaries at the end of this videoclip:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Black holes are among the most extreme objects in the known universe and astronomers using the NASA-ESA XMM-Newton space telescope have now taken detailed observations of one that's a great example of just how extreme they can be.
This black hole whips a companion star around it so fast that the star completes one orbit in just 2.4 hours, that's around two million kilometres per hour.
"The companion star revolves around the common centre of mass at a dizzying rate, almost 20 times faster than Earth orbits the Sun. You really wouldn’t like to be on such a merry-go-round in this Galactic fair!" said Erik Kuulkers, who leads the X-ray binary group at the ESA's European Space Astronomy Centre in Spain.
This black hole, named MAXI J1659-152, is estimated to be around three times the size of our Sun. It is the leftover remnant of a massive star that burned through its stellar fuel very quickly and then collapsed under the crushing weight of its own gravity, setting off a cataclysmic supernova explosion that left only the black hole and its companion behind.
The black hole's companion is a small, cool red dwarf star, about 20 per cent the size of our Sun. It orbits at about 1 million kilometres away (a little over twice the distance from Earth to the Moon), which is close enough for the black hole's immense gravity to tear matter from the star's surface. It spirals in, creating an 'accretion disk' around the singularity. The video above is an animation that shows what the stellar pair looks like as the black hole whips its companion around.
Watch videos at end of this one:
http://youtu.be/UDTuu-UAhFs
What is the relationship between the mass content of a Black Hole and its volume?
ReplyDeleteAccording to the "Big Bang" creation myth/theory...all the matter/energy of the universe originally unfolded/exploded from an infinitesimal point.
As difficult as it may be to comprehend how the entire universe could be compressed into an infinitesimal volume,..
this would mean that mass is infinitely compressible.
That is, there is no limit to how much matter/energy can be compressed.
Therefore there is no minimum limit to the size/volume of a Black Hole!
A Black Hole is defined as having sufficient mass to prevent the emission/radiation of light (photons).
This requires a Black Hole to have a minimum mass content of about 3 solar masses.
What volume would a mass like that occupy?
This does not place any restriction/limitation on the size and therefore density(mass/volume) of a Black Hole.
(One solar mass = 1.989 × 10^30 kg)
"Wherever that cutoff between a neutron star and a black hole lies — whether it's 2.5 or 2.7 or 3.0 or 3.2 solar masses — that's where you might think the minimum mass black hole could possibly be."
https://medium.com/starts-with-a-bang/the-smallest-black-hole-in-the-universe-e75c4b56e538#.tyk16vaf7