Astronomy 104 - Chapter 19 - Key Terms

Physics And Astronomy 104 with Goldwater at College of Southern Nevada

About this deck

By: Rebecca Sanchez
Textbook:

Astronomy Today Volume 2: Stars and Galaxies with MasteringAstronomy� (7th Edition)
Created: 2011-09-05
Size: 12 flashcards
Views: 13

About StudyBlue

STUDYBLUE makes things that make you better at school. Things like online flashcards with photos and audio. Things like personalized quizzes and friendly reminders about when (and what) to study next. Think of it as a digital backpack™: access to all of your study materials online and on your phone. STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj

Sign up (free) to study this.

association

Small grouping of (typically 100 or less) stars, spanning up to a few tens of parsecs across, usually rich in very young stars.

bipolar flow

Jets of material expelled from a protostar perpendicular to the surrounding protostellar disk.

brown dwarf

Remnants of fragments of collapsing gas and dust that did not contain enough mass to initiate core nuclear fusion. Such objects are then frozen somewhere along their pre-main-sequence contraction phase, continually cooling into compact dark objects. Because of their small size and low temperature they are extremely difficult to detect observationally.

evolutionary track

A graphical representation of a star's life, as a path on the H-R diagram.

globular cluster

Tightly bound, roughly spherical collection of hundreds of thousands, and sometimes millions, of stars spanning about 50 parsecs. Globular clusters are distributed in the halos around the Milky Way and other galaxies.

open cluster

Loosely bound collection of tens to hundreds of stars, a few parsecs across, generally found in the plane of the Milky Way.

protostar

Stage in star formation when the interior of a collapsing fragment of gas is sufficiently hot and dense that it becomes opaque to its own radiation. The protostar is the dense region at the center of the fragment.

protostellar disk

Swirling disk of gas and dust within which a star (and possibly a planetary system) forms. The "solar nebula," in the case of our Sun.

protosun

The central accumulation of material in the early stages of solar system formations, the forerunner of the present-day Sun.

shock wave

Wave of matter, which may be generated by a star, which pushes material outward into the surrounding molecular cloud. The material tends to pile up, forming a rapidly-expanding shell of dense gas.

star cluster

A grouping of anywhere from a dozen to a million stars which formed at the same time from the same cloud of interstellar gas. Stars in clusters are useful to aid our understanding of stellar evolution because they are all roughly the same age and chemical composition, and lie at roughly the same distance from Earth.

zero-age main sequence

The region on the H-R diagram, as predicted by theoretical models, where stars are located at the onset of nuclear burning in their cores.

About this deck

By: Rebecca Sanchez
Textbook:

Astronomy Today Volume 2: Stars and Galaxies with MasteringAstronomy� (7th Edition)
Created: 2011-09-05
Size: 12 flashcards
Views: 13

About StudyBlue

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj