Monday, December 7, 2015
Fast Wind
Astronomers found that the planet HD 189733b has winds traveling at 5400 mph from the hotter side to the cooler side. So fast. Check out the article about it.
Red Dwarf With a Strong Magnetic Field
Black Hole Grows Fast
Astronomers have discovered a black hole that grew faster than its galaxy. This normally does not happen. Read about it here.
Black Hole Eats Star
Astronomers recently saw a black hole engulf a star and release a flare that moved close to the speed of light. This is the first time anyone witnessed this. Read about it here.
Sunday, December 6, 2015
Quasar Time Delays
Quasars are objects in the universe that emit radio waves that can be detected. These quasars can be identified by their similar appearance to stars, and they exist as far away as distant galaxies. It has been postulated that some of these quasars exist at the center of some of these galaxies and interact with supermassive blackholes. Quasars can be powered by the energies released by supermassive blackholes from the absorption of matter and particles. Although quasars exist visibly at the center of galaxies, they are able to emit radio waves that expand outside of their galaxies. These radio waves are generated through a process where electrons at the center of the quasars approach the speed of light and interact with magnetic fields, allowing the electrons to travel in a helical fashion.
Quasars are also known to have high redshifts. A redshift occurs when an object's spectral lines shift to the red region of the wavelength spectrum. Redshift is equal to (λobs - λrest)/λrest where λobs is the observed wavelength, and λrest is the absorbed or emitted wavelength. The redshift value can be used to determine an object's distance. Also, for small recession velocities, the redshift is approximately equal to an object's recession velocity divided by the speed of light. A high redshift means a large distance, so quasars are very far away.
Astronomers have recently discovered a unique quasar that has five other similar-looking quasars near it that are all at the same distance. They also detected this quintuple quasar's time delays between flaring events. The time delays are important because they can be used to determine certain parameters that can help them understand things like the universe's age and expansion rate.
The image of the quintuple quasar is shown below where A-D is the quintuple quasar, and G1-G3 are galaxies:
Quasars are also known to have high redshifts. A redshift occurs when an object's spectral lines shift to the red region of the wavelength spectrum. Redshift is equal to (λobs - λrest)/λrest where λobs is the observed wavelength, and λrest is the absorbed or emitted wavelength. The redshift value can be used to determine an object's distance. Also, for small recession velocities, the redshift is approximately equal to an object's recession velocity divided by the speed of light. A high redshift means a large distance, so quasars are very far away.
Astronomers have recently discovered a unique quasar that has five other similar-looking quasars near it that are all at the same distance. They also detected this quintuple quasar's time delays between flaring events. The time delays are important because they can be used to determine certain parameters that can help them understand things like the universe's age and expansion rate.
The image of the quintuple quasar is shown below where A-D is the quintuple quasar, and G1-G3 are galaxies:
Source: http://scitechdaily.com/astronomers-detect-time-delays-between-flaring-events-in-a-quasar/
Magnets Inside Stars
Astronomers have recently found that magnetic fields inside stars are highly magnetized using a technique known as asteroseismology. Asteroseismology is used to observe the inner structure of stars using their oscillations. A star can be observed at various depths with different oscillation types. Two oscillation types are typically used: gravity modes and acoustic modes. Gravity modes have a smaller frequency with a high buoyancy, and acoustic modes have a large frequency with a high pressure.
These astronomers think that observing the magnetic fields of stars can help them understand the rotation rates, which play a large role on the lifetime of stars and the magnetic fields they generate. The rotation rate of a star can vary as its forming and even after it has formed. When a star first forms, it starts off with a cloud of gas and dust that collapses and rotates. During this process, the rotation rate of the cloud of gas continues to get higher until it eventually slows down, and a star is finally able to form. Stars can gradually lose mass as time goes by due to stellar wind, causing the rotation rate to decrease. Stars with a high rotation rate tend to lose mass quickly and experience a rapid decrease in rotation rate.
One of the things they found was that red giants have a core that is much denser than other stars. Because of this, sound waves are unable to reflect from the core and become gravity waves, resulting in unique oscillations. These gravity waves travel all the way to the core of a star and can get trapped there by the star's magnetic fields, which can result in some of the star's oscillation energy to disappear.
They also discovered that red giants have strong magnetic fields. Strong magnetic fields play a large role in how these stars evolve. These magnetic fields are similar to white dwarfs and are even 10 million times greater than the Earth's magnetic field.
Source: http://www.sciencedaily.com/releases/2015/10/151022161230.htm
These astronomers think that observing the magnetic fields of stars can help them understand the rotation rates, which play a large role on the lifetime of stars and the magnetic fields they generate. The rotation rate of a star can vary as its forming and even after it has formed. When a star first forms, it starts off with a cloud of gas and dust that collapses and rotates. During this process, the rotation rate of the cloud of gas continues to get higher until it eventually slows down, and a star is finally able to form. Stars can gradually lose mass as time goes by due to stellar wind, causing the rotation rate to decrease. Stars with a high rotation rate tend to lose mass quickly and experience a rapid decrease in rotation rate.
One of the things they found was that red giants have a core that is much denser than other stars. Because of this, sound waves are unable to reflect from the core and become gravity waves, resulting in unique oscillations. These gravity waves travel all the way to the core of a star and can get trapped there by the star's magnetic fields, which can result in some of the star's oscillation energy to disappear.
They also discovered that red giants have strong magnetic fields. Strong magnetic fields play a large role in how these stars evolve. These magnetic fields are similar to white dwarfs and are even 10 million times greater than the Earth's magnetic field.
Source: http://www.sciencedaily.com/releases/2015/10/151022161230.htm
Thursday, December 3, 2015
Explosive Energy
Scientists have recently discovered evidence for the existence of explosive releases of energy in Saturn's magnetic bubble. This was done using data from the Cassini spacecraft.
These explosive releases of energy are produced through magnetic reconnection. Magnetic reconnection is a process where oppositely directed magnetic field lines in a plasma break and reconnect. Throughout this process, magnetic energy is converted to thermal energy, kinetic energy, and particle acceleration. Magnetic reconnection typically takes place on timescales between Alfcenic timescales and resistive diffusion, and it is involved in many events in the solar system, such as solar magnetic activity and auroras near the polar regions of magnetized planets.
These scientists found that the Cassini spacecraft encountered a region of Saturn where magnetic reconnection was occurring. This has given them an idea of how Saturn's magnetosphere eliminates gas from its moon, Enceladus.
A magnetosphere is the space surrounding an astronomical object that is controlled by the object's magnetic field. Magnetospheres vary in type and structure depending on certain factors. The type of astronomical object, the object's spin period, the magnetic dipole axis, solar wind flow direction and magnitude, the type of axis on which the object spins, and the nature of sources of plasma and momentum all play a role in determining the type and structure of magnetospheres. Magnetospheres can also be classified into two categories: intrinsic and induced. A magnetosphere is considered intrinsic when the main opposition to the solar wind flow is the object's magnetic field. A magnetosphere is considered induced if the object's magnetic field does not oppose the solar wind flow. A magnetosphere is neither intrinsic nor induced if the radius of the object is equal to the Chapman-Ferraro distance (i.e. the distance at which an object can resist the solar wind pressure).
The results that these scientists discovered show that all plasma is able to escape from Saturn's magnetosphere. They had previously thought that magnetic reconnection prevented this from occurring when this wasn't actually the case.
Source: http://www.sciencedaily.com/releases/2015/12/151201094239.htm
These explosive releases of energy are produced through magnetic reconnection. Magnetic reconnection is a process where oppositely directed magnetic field lines in a plasma break and reconnect. Throughout this process, magnetic energy is converted to thermal energy, kinetic energy, and particle acceleration. Magnetic reconnection typically takes place on timescales between Alfcenic timescales and resistive diffusion, and it is involved in many events in the solar system, such as solar magnetic activity and auroras near the polar regions of magnetized planets.
These scientists found that the Cassini spacecraft encountered a region of Saturn where magnetic reconnection was occurring. This has given them an idea of how Saturn's magnetosphere eliminates gas from its moon, Enceladus.
A magnetosphere is the space surrounding an astronomical object that is controlled by the object's magnetic field. Magnetospheres vary in type and structure depending on certain factors. The type of astronomical object, the object's spin period, the magnetic dipole axis, solar wind flow direction and magnitude, the type of axis on which the object spins, and the nature of sources of plasma and momentum all play a role in determining the type and structure of magnetospheres. Magnetospheres can also be classified into two categories: intrinsic and induced. A magnetosphere is considered intrinsic when the main opposition to the solar wind flow is the object's magnetic field. A magnetosphere is considered induced if the object's magnetic field does not oppose the solar wind flow. A magnetosphere is neither intrinsic nor induced if the radius of the object is equal to the Chapman-Ferraro distance (i.e. the distance at which an object can resist the solar wind pressure).
The results that these scientists discovered show that all plasma is able to escape from Saturn's magnetosphere. They had previously thought that magnetic reconnection prevented this from occurring when this wasn't actually the case.
Source: http://www.sciencedaily.com/releases/2015/12/151201094239.htm
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