Match the items below with the correct type of supernova

Match the items below with the correct type of supernova: massive star supernovae and white dwarf supernovae.

1. Star explodes completely, leaving no compact object behind
2. Can only occur in a galaxy with ongoing star formation
3. Black hole or neutron star left behind
4. Can only occur in a binary system
5. Can occur in a very old star cluster
6. Spectra always lack strong hydrogen lines
7. Has a brighter peak luminosity

The correct answer and explanation is :

Here is the correct matching of the items with their respective types of supernovae:

1. Star explodes completely, leaving no compact object behind:

• Massive star supernovae
  This occurs when a massive star (typically greater than 8 solar masses) ends its life in a core-collapse supernova. The core collapses into a black hole or neutron star, but the outer layers of the star are expelled, leaving no remnant compact object behind.

2. Can only occur in a galaxy with ongoing star formation:

• Massive star supernovae
  Massive star supernovae are linked to the death of large stars, which are more likely to form in star-forming regions of a galaxy. Since these stars have short lifespans, they are more common in galaxies with active star formation.

3. Black hole or neutron star left behind:

• Massive star supernovae
  After the explosion, the core of a massive star can collapse into a black hole or a neutron star, depending on the mass of the remnant. This is one of the defining features of massive star supernovae.

4. Can only occur in a binary system:

• White dwarf supernovae
  A white dwarf supernova (Type Ia) occurs when a white dwarf in a binary system accretes matter from a companion star. When the white dwarf’s mass exceeds the Chandrasekhar limit (~1.4 solar masses), it ignites a thermonuclear explosion that completely destroys the white dwarf.

5. Can occur in a very old star cluster:

• White dwarf supernovae
  White dwarf supernovae are more likely to occur in old star clusters because white dwarfs are remnants of older stars. These supernovae can be triggered by binary interactions in environments with older stars.

6. Spectra always lack strong hydrogen lines:

• White dwarf supernovae
  Type Ia supernovae, which are white dwarf supernovae, do not exhibit hydrogen lines in their spectra. This is because they arise from carbon and oxygen-rich white dwarfs rather than from stars with hydrogen in their outer layers.

7. Has a brighter peak luminosity:

• White dwarf supernovae
  White dwarf supernovae (Type Ia) generally have a much higher peak luminosity than massive star supernovae. This is due to the thermonuclear explosion of a white dwarf, which releases an enormous amount of energy, making them among the most luminous events in the universe.

Explanation:

Massive Star Supernovae (Core-collapse Supernovae):
These supernovae occur when a massive star runs out of nuclear fuel and its core collapses under gravity. The outer layers of the star are expelled in a catastrophic explosion. The remnant core typically becomes a neutron star or black hole. This type of supernova can only happen in galaxies with ongoing star formation because it requires massive, short-lived stars. The spectra of massive star supernovae often show hydrogen lines, reflecting their hydrogen-rich progenitors.

White Dwarf Supernovae (Type Ia Supernovae):
These supernovae result from the thermonuclear explosion of a white dwarf in a binary system. The white dwarf accretes material from its companion, leading to a catastrophic ignition once it reaches a critical mass. This type of supernova can occur in old star clusters, as the progenitor white dwarfs are remnants of older stars. These supernovae have no hydrogen lines in their spectra, and they tend to be brighter, with a more consistent peak luminosity, making them useful for measuring cosmic distances.