In: Physics
Compare a nova to a Type I supernova to a Type II supernova. What do these three objects have in common? How are these three objects different?
A nova , Type I supernova, and Type II supernova have things common which is all three are from a dying star. And all three generate tremendous energy.
A nova is an explosion from the surface of a white-dwarf star in a binary star system. A nova occurs when the white dwarf, which is the dense core of a once-normal star, “steals” gas from its nearby companion star. When enough gas builts up on the surface of the white dwarf it triggers an explosion. For a brief time, the system can shine up to a million times brighter than normal. As long as it continues to take gas from its companion star, the white dwarf can produce nova outbursts at regular intervals. A supernova is a violent stellar explosion that can shine as brightly as an entire galaxy of billions of normal stars. Astronomers divide supernovae into two groups: Type I and Type II.
Type I supernovae most likely form as a white dwarf “steals” hot gas from a companion star. If enough gas piles up on the surface of the white dwarf, a runaway thermonuclear explosion blasts the star to bits, leaving nothing behind. These are the brightest supernovae, and can be used to measure the distances to other galaxies.
Type II supernovae are the final stage in the evolution of stars that are at least eight times as massive as the Sun. Such a star reaches a point where it can no longer produce nuclear energy in its core. Without the outward pressure created by this energy, gravity wins out and causes the star’s core to collapse to form a neutron star or black hole. The star’s outer layers “rebound” violently, blasting into space at several percent of the speed of light.
The major difference between a nova and a supernova is that in a supernova a lot of the object’s mass is ejected with the explosion. The amount of this mass is more than the mass of the sun. Where as in a nova, very less mass is ejected as compared to that in a supernova.
A nova does not destroy its host star whereas a super nova does.
A nova can be seen at the same place multiple times, on the other hand, a supernova cannot.