[ noh-vuh ]
/ ˈnoʊ və /
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Definition of nova

noun, plural no·vas, no·vae [noh-vee]. /ˈnoʊ vi/. Astronomy.
a star that suddenly becomes thousands of times brighter and then gradually fades to its original intensity.
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“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.
Compare supernova.

Origin of nova

1680–90; <New Latin: noun use of feminine of Latin novusnew


no·va·like, adjective

Other definitions for nova (2 of 2)

[ noh-vuh ]
/ ˈnoʊ və /

Also called Nova Salmon. a Pacific salmon cured in the style of Nova Scotia salmon.
(lowercase) (loosely) any smoked salmon.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What is a nova?

A nova is a star that temporarily becomes extremely bright and then returns to its original brightness. The plural of nova is novas or novae.

A star is an object in outer space that is basically a big bright ball of gas. The Sun is the only star in our solar system.

The Sun is a medium-sized star in the middle of its life. When a star the size of our Sun or smaller nears the end of its life, it becomes a white dwarf. A white dwarf is small (for a star) and, because of its size, not very bright. However, a white dwarf is very dense, so it has a strong gravitational pull.

In a binary solar system, there are two stars. Sometimes, a white dwarf star in a binary system will pull hydrogen gas from a bigger, neighboring star. Eventually, it may pull so much hydrogen together that it causes an explosion. This explosion causes the white dwarf to become incredibly bright and become what is called a nova.

A nova is temporary. Typically, a white dwarf only stays really bright for several days before returning to its original state. The white dwarf may again start pulling hydrogen from its neighbor and eventually again turn into a nova. Each cycle could take anywhere from a thousand to hundreds of thousands of years.

Why is nova important?

The first records of the word nova come from around 1680. It comes from the New Latin word novus, meaning “new.” In the past, we thought that a nova was a brand new star.

Now we know that novas are very old stars that are nearing the end of their lives. Why did we think they might be new stars? Because white dwarfs are both small and not very bright, we cannot see them with just our eyes from Earth. However, when it becomes a nova, the white dwarf becomes so bright that we can suddenly see it unaided in our night sky. Past stargazers believed this was a new star being born. As time passed, telescopes helped astronomers discover the existence of white dwarfs and learn what novas really are.

Why is nova important?

If a large white dwarf or a bigger star accumulates a huge amount of hydrogen, it may create a massive explosion known as a supernova. Unlike a nova, a supernova is the explosion of the star itself and can result in celestial bodies known as neutron stars or even a black hole.

What are real-life examples of nova?

Novas are of great interest to astronomers and researchers studying space.


Quiz yourself!

True or False?

A nova is a new star that is created when hydrogen gathers together into a big cloud of bright gas.

How to use nova in a sentence

British Dictionary definitions for nova

/ (ˈnəʊvə) /

noun plural -vae (-viː) or -vas
a variable star that undergoes a cataclysmic eruption, observed as a sudden large increase in brightness with a subsequent decline over months or years; it is a close binary system with one component a white dwarfCompare supernova

Word Origin for nova

C19: New Latin nova (stella) new (star), from Latin novus new
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for nova

[ nōvə ]

Plural novae () novas
A white dwarf star that suddenly and temporarily becomes extremely bright as a result of the explosion at its surface of material accreted from an expanding companion star. The material, mostly hydrogen and helium, is attracted by the white dwarf's gravity and accumulates under growing pressure and heat until nuclear fusion is ignited. Unlike a supernova, a nova is not blown apart by the explosion and gradually returns to its original brightness over a period of weeks to years. Because of their sudden appearance where no star had been previously visible, novae were long thought to be new stars. Since 1925, novae have been classified as variable stars. Compare supernova.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for nova

[ (noh-vuh) ]

In astronomy, the appearance of a new star in the sky (nova is Latin for “new”). Novae are usually associated with the last stages in the life of a star. (See supernova.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.