The narrow component of the spectral lines is produced by circumstellar gas, ionised as the shock breaks out of the star by the accompanying UV flash. The intermediate and broad components are produced by shocked, high-velocity supernova ejecta, the result of the collision of the ejecta with the circumstellar gas .
What is the difference between a Type Ia and a Type Ib supernova?
Type Ib/Ic supernovae are distinguished from Type Ia by the lack of an absorption line of singly ionized silicon at a wavelength of 635.5 nanometres . ... Type Ic supernovae are distinguished from Type Ib in that the former also lack lines of helium at 587.6 nm.
What kind of supernova exhibits strong hydrogen lines in its spectrum?
The presence of hydrogen lines in the spectra of Type II supernovae (SNII) characterises this class of object. These lines have P Cygni profiles and are usually very broad, indicating rapid expansion velocities for the material in the supernova.
How are supernovas categorized?
Supernovae are classified based on the presence or absence of certain features in their optical spectra taken near maximum light . ... We now know that Type II, Type Ib and Type Ic supernovae result from the core-collapse of massive stars, while Type Ia supernovae are the thermonuclear explosions of white dwarfs.
What causes a type 1b supernova?
Type Ib: Type Ib supernovae are formed when a massive star collapses under its own gravity . This star must have its outer envelope of hydrogen stripped away, because we observe no hydrogen in these spectra of these objects. However, we do observe the second ‘onion layer’ of helium.
What are the 2 types of supernovae?
There are two main types of supernovae, the Type I and the Type II .
What is the difference between type I and type II supernova?
A star can go supernova in one of two ways: Type I supernova: star accumulates matter from a nearby neighbor until a runaway nuclear reaction ignites. Type II supernova: star runs out of nuclear fuel and collapses under its own gravity .
Why do Type Ia supernovae have no hydrogen in their spectra?
If the star’s iron core is massive enough , it will collapse and become a supernova. ... However, if the original star was so massive that its strong stellar wind had already blown off the hydrogen from its atmosphere by the time of the explosion, then it too will not show hydrogen spectral lines.
What remnant does a supernova type Ia leave?
Type Ia supernovae are several times more luminous than Type Ib, Ic, and Type II supernovae, leave no core remnant behind , and result from when a low-mass star’s core remnant (a white dwarf) detonates. They have a strong ionized silicon emission line at 615 nm.
Which of the following is an important difference between a Type Ia and a Type II supernova?
A type I supernova occurs in closed binary systems where two average stars orbit around each other quite closely. When one of the stars exhausts its hydrogen it will enter the red giant stage and then collapse into a white dwarf . ... A type II supernova occurs in larger stars of around 10 solar masses.
Can our sun go supernova?
The Sun as a red giant will then... go supernova? Actually, no—it doesn’t have enough mass to explode . Instead, it will lose its outer layers and condense into a white dwarf star about the same size as our planet is now. ... A planetary nebula is the glowing gas around a dying, Sun-like star.
Why do we say we are made of stardust?
The star then explodes outward as a supernova. This supernova explosion creates all the elements heavier than iron. ... And, these particles were all forged in the nuclear fusion fires of stars. We truly are made of star dust.
What is the difference between Type 1 and Type 2 supernovae quizlet?
What is the difference between Type Ia and Type II supernovae? Physically, type II supernovae are caused by the collapse of a massive star . Type Ia supernovae are driven by a white dwarf which accretes enough mass to exceed the Chandrasekhar limit and collapses into a neutron star.
When was the last supernova seen?
The most recent supernova to be seen in the Milky Way galaxy was SN 1604 , which was observed on October 9, 1604. Several people, including Johannes van Heeck, noted the sudden appearance of this star, but it was Johannes Kepler who became noted for his systematic study of the object itself.
What happens when a star goes supernova?
It’s a balance of gravity pushing in on the star and heat and pressure pushing outward from the star’s core. When a massive star runs out of fuel, it cools off. This causes the pressure to drop. ... The collapse happens so quickly that it creates enormous shock waves that cause the outer part of the star to explode!
How long does it take for a star to go supernova?
The explosion of a supernova occurs in a star in a very short timespan of about 100 seconds .
