dwarf star

nounAstronomy.

any of the ordinary main sequence stars, as those of spectral types O, B, A, F, G, K, and M.

Origin of dwarf star

First recorded in 1910–15

Also called dwarf.

Compare white dwarf.

Words Nearby dwarf star

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use dwarf star in a sentence

A team of astronomers found 19 strange radio signals from red dwarf stars, four of which they think could be coming from orbiting exoplanets, potentially marking the first time exoplanets have been discovered using radio frequencies.
These strange radio signals might not be coming from stars | Leto Sapunar | October 14, 2021 | Popular-Science
The typical cosmic magnets—such as red dwarf stars, magnetars, or brown dwarfs—shine brightly with other forms of radiation.
Astronomers discover disappearing radio source in the Milky Way’s center | Charlie Wood | October 13, 2021 | Popular-Science
There’s perhaps nothing more ancient and unchanging than the sun, a yellow dwarf star that has illuminated Earth for over 4 billion years.
What happens when the sun burns out? | Rahul Rao | October 7, 2021 | Popular-Science
Indeed, the team identified a group of 11 potential Hycean planets orbiting red dwarf stars near Earth—within 35 and 150 light years—worthy of observation.
Newly Classified Hycean Exoplanets Could Accelerate the Search for Alien Life | Jason Dorrier | August 29, 2021 | Singularity Hub

British Dictionary definitions for dwarf star

dwarf star

noun

any luminosity class V star, such as the sun, lying in the main sequence of the Hertzsprung-Russell diagram: Also called: main-sequence star See also red dwarf, white dwarf

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 dwarf star

dwarf star

A relatively small, low-mass star that emits an average or below-average amount of light. Most dwarf stars, including the Sun, are main-sequence stars, the principal exception being white dwarfs, which are the remnants of larger collapsed stars. Main-sequence dwarfs burn their hydrogen at a much slower rate than giant and supergiant stars and are consequently less luminous and have longer lifespans than those non-main-sequence stars do.

a closer look

Despite their diminutive name, most dwarf stars are quite normal main-sequence stars and come in a wide variety of sizes, formed from protostars with sufficient mass to begin the process of nuclear fusion. But there are other stellar and quasistellar objects called dwarf stars as well. Brown dwarfs are formed when insufficient mass accretes for nuclear fusion to take place; brown dwarfs thus never become proper stars. Other kinds of dwarf stars result from the further evolution of main-sequence stars not massive enough to become neutron stars or black holes (which form from the burned-out core of a supernova). The type known as a white dwarf is the remnant of a red giant star that has burned nearly all its fuel. The mutual gravitational attraction of its atoms, no longer counterbalanced by the outward pressure of burning fuel within, causes the star to collapse in on itself. After it contracts and blows its outer layers away as a planetary nebula, the red giant stabilizes as a white dwarf and slowly fades. Our Sun is of a size and mass that will probably cause it to evolve first into a small red giant and eventually into a white dwarf. Red dwarfs have a lower mass and luminosity than white dwarfs, and black dwarfs, if any yet exist, are even less luminous, no longer giving off any detectable radiation.

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