Encyclopedia

protoplanet

Also found in: Dictionary, Wikipedia.

protoplanet

(proh -toh-plan-it) An evolving planet in the process of accretion, together with any of its satellites forming by accretion at the same time in the vicinity of the planet. The dust cocoon around some T Tauri stars has the attributes of a protoplanetary system. In the one typical case, HL Tauri, it forms a flattened disk, radius 160 AU, containing about one Earth mass of dust; allowing for dust condensed into planetesimals and the system's gas content, it could condense into several planets. Infrared observations from the satellite IRAS show dust around over 40 slightly older stars, including Vega, indicating either a protoplanetary system or a swarm of comets. See also Beta Pictoris.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

protoplanet

[′prōd·ō‚plan·ət]
(astronomy)
A precursor of one of the giant planets, which is believed to have formed, along with its satellites, from a minisolar nebula in a manner similar to that of the formation of the sun and planets.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
Mentioned in
References in periodicals archive
It took about 95,000 photographs of the dwarf planet and protoplanet and collected over 167 GB of scientific data.
A team of scientists under Stephanie Sallum in Tucson, Arizona used adaptive optics observations to record these protons and thereby detect the formation of the protoplanet, which orbits a relatively young star just two million years old.
It involves devastating collisions with other small protoplanets, as well as with a multitude of showering, tumbling worldlets.
If we assume that a protoplanet took about a million years to lose most of its volatile elements, then c is found to be ~[10.sup.-3].
Lastly, water, once it is formed, must be gathered together on a protoplanet before life can evolve--essential sequencing.
By that time, most of the iron and other heavy elements had already settled into the cores of each protoplanet, which merged inside Earth after the impact.
Dawn previously explored the protoplanet Vesta for 14 months, from 2011 to 2012, capturing detailed images and data about that body.
These impish nicknames arise from the fundamental basis of the theory: a Mars-sized protoplanet, named Theia by astronomers, crashed into the primordial Earth billions of years ago.
Copyright © 2003-2025 Farlex, Inc Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.