substellar

adjective

sub·​stel·​lar ˌsəb-ˈste-lər 

variants or sub-stellar

of a celestial object

: having less mass than a star : not having the mass required to sustain nuclear fission (see fission entry 1 sense 3)

Subsequent hunts within young stellar clusters have flushed out droves of brown dwarfs. Prime targets are the Pleiades cluster and star-forming regions in Orion and Taurus, where substellar bodies rival stars in number.

—Robert Irion

Very often, the most publicized events in astronomy involve the detection of fundamentally new types of objects. The discovery of a substellar object, a "brown dwarf" some dozens of times as massive as Jupiter, falls in this category.

—Physics Today

Examples of substellar in a Sentence

Recent Examples on the Web

If this rule extends to objects that are even more diminutive, brown dwarfs may be the most ubiquitous substellar objects in the universe. —Phil Plait, Scientific American, 19 Jan. 2024

In Louisiana, the state and the U.S. Army Corps of Engineers—which enters with a substellar reputation, to say the least, given its colossal Katrina failures—is currently pursuing a $50 billion shoreline restoration project, known as the Mid-Barataria Sediment Diversion. —Nick Martin, The New Republic, 8 Mar. 2021

Word History

First Known Use

1949, in the meaning defined above