ul·​tra·​lu·​mi·​nous ˌəl-trə-ˈlü-mə-nəs How to pronounce ultraluminous (audio)
: emitting an extremely large amount of electromagnetic radiation (such as light, X-rays, or infrared radiation) : extremely luminous
an ultraluminous infrared galaxy
We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources.Rob Fender et al.

Examples of ultraluminous in a Sentence

Recent Examples on the Web Even rarer and more spectacular are ultraluminous infrared galaxies, or ULIRGs. Aaron S. Evans, Scientific American, 1 Dec. 2021 These are ULXs, or ultraluminous X-ray sources. Alison Klesman, Discover Magazine, 21 Feb. 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ultraluminous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1878, in the meaning defined above

Time Traveler
The first known use of ultraluminous was in 1878

Dictionary Entries Near ultraluminous

Cite this Entry

“Ultraluminous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ultraluminous. Accessed 20 Apr. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!