- 3187 - NEUTRON STARS - from magnetars to pulsars? Stars larger than our Sun die with a different fate. They explode as Supernovae and their remnant cores become Pulsars of various types of Neutron Stars. Stars range in mass from 0.2 Solar Mass to 120 Solar Mass. Neutron Stars are in the 8 to 25 Solar Mass Range:
- -------------- 3187 - NEUTRON STARS - from magnetars to pulsars?
- When a star runs out of fuel it dies. When our star dies, the one we call our Sun, it will become a White Dwarf. When the central 10% of our Sun has no more hydrogen for fusion the core will shrink and the hydrogen fusion will move from the center to a shell surrounding a core of helium.
-
- This will happen about 5,000,000,000 years from now. When it happens the Sun will expand to many times its present size. The Sun will continue to get its energy from hydrogen fusion into helium until about 50% of the total mass is helium. Then, quite suddenly, it will switch to fusing helium into carbon and oxygen.
-
- When all the helium at the core is converted into carbon and oxygen the Sun’s core will go back to fusing hydrogen that is in the shell and a second process will begin. The Sun will increase in luminosity by 1,000 times.
-
- It will become unstable and start to pulsate It will shrink and grow in cycles that last about one year, becoming a Mira Variable Star. These pulsations produce waves of lost atmosphere until all that is left is the carbon-oxygen remnant. What is left is extremely dense. A teaspoon of mass would weigh one ton. The star is then called a White Dwarf.
-
- Stars larger than our Sun die with a different fate. They explode as Supernovae and their remnant cores become Pulsars of various types of Neutron Stars. Stars range in mass from 0.2 Solar Mass to 120 Solar Mass. Neutron Stars are in the 8 to 25 Solar Mass Range:
-
----------------------- 0.2 to 7 Solar Mass --------- White Dwarfs
-
----------------------- 8 to 25 Solar Mass --------- Neutron Stars
-
----------------------- 26 to 120 Solar Mass --------- Blackholes
-
- The remnants after the Supernovae explodes are Neutron Stars are that are 1.4 Solar Mass and greater. When the mass is this great the center of the star cannot withstand the pressure against the balancing outward pressure of electron degeneracy.
-
- The electrons collapse into the nuclei and the inner layers of the star becomes neutrons. Matter at the surface of the star can remain largely of electrons and positively charged atomic nuclei. This matter is the neutron star’s crust.
-
- The Neutron Stars become Pulsars of various types. Don’t be put off by all the names and acronyms. Astronomers are studying and categorizing different behaviors to understand how Pulsars evolve.
-
--------------------- Magnetars
-
--------------------- X-ray Pulsars
-
--------------------- Soft Gamma Repeaters (SGRs)
-
--------------------- Rotating Radio Transients (RRATs)
-
--------------------- Compact Central Objects (CCOs)
-
--------------------- Isolated Neutron Stars (INSs)
-
--------------------- Rotating Powered Pulsars (PPRs)
-
------------------------------------------------ It is a zoo of Pulsars.
- This is not unlike the field of Particle Physics that discovered a zoo of sub-atomic particles and did not know what to make of it. Until, they learned enough to come up with the “Standard Model” that introduced the quarks as fundamental particles.
- The Crab Nebula is a famous supernova. It has a Neutron Star at its center that rotates 30 times per second. The reason we can measure this rotation is a beam of radiation sweeps by Earth like a lighthouse beam 30 times every second.
-
- Rotation Powered Pulsars (PPRs) have a narrow beam of radiation emanating from their magnetic poles. With the magnetic axis slightly misaligned with the rotational axis the beams rotate like a lighthouse beacon. Over 2,000 of the lighthouse Pulsars have been discovered in our Milky Way Galaxy.
-
- Neutron Stars have been found to rotate up to 700 revolutions per second. On the surface of these stars you would be pulling over 1,000,000 G’s. How fast can these stars spin without flying apart?
-
- Neutron stars are born in Supernovae explosions. As the remainder of the exploded star collapses, the Conservation of Momentum requires that the velocity of rotation increase. This is analogous to an ice skater pulling in her arms as she twirls on the ice.
-
- A magnetic field in the rotating star acts as a brake to the rapid rotation. Again, the Conservation of Energy causes radiation to emit from the rotating magnetic poles. Slowing rotational energy is transformed to kinetic energy of particles leaving the star. The intensity of the magnetic field can be a trillion times that of Earth’s , up to 10^12 gauss.
-
- Magnetars have magnetic fields up to 1,000 times greater than that of regular radio pulsars. Magnetic flares off the surface of the spinning star can release as much energy in seconds as the Sun will release in 1,000 years. Astronomers think the flares are caused by “earthquakes, rather starquakes”, opening a crack in the surface of the Neutron Star.
-
- Compact Central Objects (CCOs) are located in the centers of supernova remnants. Cassiopeia A is an example. Very low rotation rates imply very high magnetic fields..
- PSR B1509-58 is a pulsar that rotates every 150 milliseconds and powers an X-ray nebula.
-
- About 12 Rotating Radio Transients stars, (RRATs) have been identified to date.
-
- 7 Isolated Neutron stars (INSs) have been discovered. They have very low X-ray luminosity and have rotational periods of 3 to 11 seconds.
-
-------- TYPES OF PULSARS ------------ ------ GAUSS ------------- AGE,YEARS
---------------------------- -------- ---------------
-
-------- High Magnetic Field Radio Pulsars ----- 10^15 gauss ------------- 10,000,000
-
-------- Magnetars ----------------------------------- 10^14 gauss ------------- 100
-
-------- Isolated Neutron Stars --------------------- 10^13 gauss ------------- 1,000,000
-
-------- Rotational Powered Pulsars --------------- 10^11 gauss ------------- 1,000,000
-
-------- Rotating Radio Transients ----------------- 10^4 gauss ------------- 1,000,000
-
-------- Compact Central Objects ------------------ 10^10 gauss ------------- 100
-
-------- Millisecond Pulsars ------------------------- 10^9 gauss ------------- 10,000,000,000
-
- Neutron Star astronomers have their work cut out for them. How to understand the physics that control these supernova remnant behaviors. How to understand their evolution.
-
- There are relationships between temperature effects, magnetic field decays, spin rates, electrical resistance of the curst, the number of pulsars in each galaxy that need to be understood. There is likely a grand unifying theory in all this data if we just understood it. That is what makes it interesting.
-
- How dense is a neutron star? Radius is 10 kilometers, mass is 2*10^30 Kilograms.
-
- Density = 2*10^30 / 4*pi*10^12 /3 = 0.5* 10^12 kilograms / centimeter^3.
-
- One sugar cube of Neutron Star weighs 500,000,000,000 kilograms. At these high densities our math formulas in physics no longer work. We need new math to calculate behaviors of Neutron Stars.
-
------------------------------ Other Reviews about neutron stars:
-
- 3113 - NEUTRON STARS - We have much more to learn about Neutron Stars. Each property shows itself a little differently depending on our observations and the instruments we use to make the discoveries. It is possible that Neutron Stars become Quark Stars before they become Black Holes. All stars, depending on their size, are destined to evolve into one of these three, :(1) White Dwarf (2) Neutron Star(3) Black Hole. The White Dwarf goes through a giant Red Dwarf stage before it collapses but it is not large enough to go supernova. The Neutron Star and Black Hole both evolve after a giant Supernova explosion.
-
- 3084 - NEUTRON STARS - how can they carry charges? Can we have a super-strong magnetic field coming from the inside of a blackhole? We see blackhole magnetic fields, but are they generated inside the event horizon or outside, such as in the accretion disk? And if they do come from the inside, what’s the physics behind that?
-
- 2999 - NEUTRON STARS - and magnetars? - Astronomers may have captured the first good look at giant flares from the strongest magnets in the universe. The likely cause of these giant flares that are Starquakes trillions of trillions of times stronger than any earthquakes.
-
- 2960 - NEUTRON STARS - to measure expansion of the universe. How fast is the Universe expanding? Ever since the expanding Universe was first discovered nearly 100 years ago, it’s been one of the biggest questions plaguing cosmology. If you can measure how fast the Universe is expanding right now, as well as how the expansion rate is changing over time, you can figure out everything you’d want to know about the Universe as a whole.
-
- 2950 - NEUTRON STARS - it dosn’t get any stranger? Astronomy has many, many strange things to try to figure out. Let’s start with “neutron stars“. The crushing gravity, intense magnetic fields, and lightning-fast rotations place “neutron stars” among the most exotic beasts in the universe. Next come the most powerful magnetic fields in the universe wrack the searing surfaces of neutron stars called “magnetars“. These magnetic monsters form one of the most eccentric branches on the neutron star-pulsar family tree.
-
- 1897 - The mysterious Neutron Stars, Pulsars, and Quasars create radio bursts of energy that astronomers are still trying to explain. There are mysterious radio bursts coming to us from far away galaxies. Since 2007 some 20 pulses have been recorded. The pulses only last for a few milliseconds, but, they release the energy equal to a million suns.
-
- 1327 - Neutron Stars - The surface is solid and harder that a diamond, 50 trillion times denser than solid lead. Its magnetic field is a trillion times more intense than that of our Sun.
-
- 1273 - Neutron Star - Are Astronomical Mergers in our Future? Mergers are going on all the time in our Universe. Some are large, some are relatively small. Our galaxy is relatively quiet right now. We should use this time to study what might happen when these mergers do occur?
-
- 1192 - 3187 - The new zoo of Pulsars. When a star runs out of fuel it dies. When our star dies, the one we call our Sun, it will become a White Dwarf. When the central 10% of our Sun has no more hydrogen for fusion the core will shrink and the hydrogen fusion will move from the center to a shell surrounding a core of helium. This will happen about 5,000,000,000 years from now. When it happens the Sun will expand to many times its present size. The Sun will continue to get its energy from hydrogen fusion into helium until about 50% of the total mass is helium. Then, quite suddenly, it will switch to fusing helium into carbon and oxygen.
-
- 861 - Cannon Ball Star. Astronomers have discovered a Neutron Star shooting across the Milky Way Galaxy at 3,000,000 miles per hour. The star is traveling so fast it exceeds the escape velocity for the galaxy and will launch itself into intergalactic space. Astronomers are trying to find the cannon that could shoot this star into space with so much energy.
-
- 642 - Neutron Stars, Pulsars, and Magnetars.
-
- 21 - 381 - Stars grow old and become White Dwarfs, Neutron Stars, or Blackholes
-
- June 10, 2021 NEUTRON STARS - magnetars to pulsars? 1192 3187
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
--------------------- --- Thursday, June 10, 2021 ---------------------------
No comments:
Post a Comment