Quasar vs Nova (How Are They Different?)

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A nova is a relatively small yet bright nuclear fusion outburst on a white dwarfs surface when too much energy from its companion red giant star is consumed, whereas quasars are arguably the brightest entities in our universe that surround supermassive black holes, ejecting extremely bright jet particles angled slightly towards Earth.

The two are very different from one another despite the small connection in being more luminous in comparison to the rest of the universe. Continue reading for a more thorough look at quasars and novas.

What Is A Quasar?


Quasars are extremely bright celestial objects powered by supermassive black holes, found in the center of galaxies. They tend to also be referred to as an active galactic nucleus or AGN for short.

Quasars were initially called quasi-stellar radio sources however, this name isn’t entirely consistent with the type of waves they generate as only around 10 percent of all quasars that have been discovered produce strong radio waves.

As for how bright they can be, quasars have been observed to exceed levels that are upwards of 100 times the brightness of the galaxies that hold them.

Although not an absolute, many scientists believe these bright objects are formed when light escapes at the edge of a supermassive black hole just before reaching its event horizon. Some light gets drawn in whilst other particles jet out at a tremendous pace, which is how the erratic and powerful light of a quasar forms.

At this moment in time we have discovered roughly 750,000 unique quasars extending across various ages, with the farthest from us roughly 13 billion light years away.

Therefore, not only are these enigma’s extraordinarily powerful but, they can even be used as time capsules to observe how our universe came to be, relatively close to when the theorised big bang occurred.

What Is A Nova?

White dwarf star

A nova will occur when a white dwarf consumes too much energy from its binary companion star. This causes nuclear fusion which momentarily induces a very bright energy outburst on the stellar remnants surface.

This will happen when the surface of the white dwarf heats up to around 20,000 degrees celsius, which allows it to act as if it were the core of an active star.

The energy produced is significant, where it ejects energy in the region of 100,000 times more powerful than the white dwarfs typical cycle.

It will need to release this excess energy otherwise it wouldn’t be able to conserve its form therefore, the exterior explodes creating a nova explosion that can even increase in brightness over the course of a few months.

Some white dwarfs tend to have nova outbursts a few times a century whilst others are much rarer. Ultimately for the explosion to occur, it will depend on how much hydrogen can be provided by a white dwarfs red giant companion star.

Although not the most commonly observed cosmic activity, scientists tend to observe in the region of 40 new novas every year in the Milky Way, with the true real number in billions throughout the cosmos.

Similarities Between A Quasar And Nova

The only similarity between the two, although small, would have to be that quasars and novas are amongst the brightest entities in our universe and they both activate around stellar remnants, black holes for quasars and white dwarfs for novas.

Other than this, they differ quite significantly from one another.

Differences Between A Quasar And Nova

The differences between a quasar and nova would include the following:

  • A nova explosion is certainly bright, eclipsing that of 100,000 suns for a few months however, quasars are able to outshine entire galaxies for millions of years and are even regarded amongst the most luminous phenomena in the known universe.
  • Quasars have a lifespan of around 10 million years whereas a nova outburst lasts for a few months and can happen upwards of a few times a century on a white dwarfs surface.
  • Quasars can only be found around black holes making them a far rarer phenomena than novas, which can happen among a large number of white dwarfs in binary star systems.
  • Quasars are far hotter than novas, where they typically are 100+ billion degrees celsius. A nova are typically much cooler (although still very hot) reaching 20 million degrees celsius on average.
  • Quasars much larger in size ranging anywhere from a few million to billions of kilometers on diameter whereas novas are only a small portion of a white dwarfs size, which are already small themselves.
  • Quasars are amongst the oldest observable celestial objects in our universe.


Quasars are active galactic nuclei that surround supermassive black holes, burning at insane temperatures eclipsing 100 billion degrees celsisu and shining so bright that we can observe some 13 billion light years away from us, whilst novas are a much more tame luminous outburst that materializes when a white dwarf’s exterior consumes too much hydrogen.

In the grand scheme of things, quasars are grander, larger, more luminous and even last longer than your average nova. That’s why despite novas coming across as very bright, it simply does not hold a candle to the magnitude of power quasars have over them.

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