Lesson 179 of 1524
The Birth of Stars and the Discovery of Planets outside the Solar System
The accumulation of material halts when a protostar develops a strong stellar wind, leading to jets of material being observed coming from the star.
Practice this chapterThe accumulation of material halts when a protostar develops a strong stellar wind, leading to jets of material being observed coming from the star. Most stars form in giant molecular clouds with masses as large as 3 × 10 6 solar masses.
The most well-studied molecular cloud is Orion, where star formation is currently taking place. Protostars generate energy (and internal heat) through gravitational contraction that typically continues for millions of years, until the star reaches the main sequence
giant molecular clouds — large, cold interstellar clouds with diameters of dozens of light-years and typical masses of 10 5 solar masses; found in the spiral arms of galaxies, these clouds are where…. most well-studied molecular cloud — Orion, where star formation is currently taking place. stellar wind — the outflow of gas, sometimes at speeds as high as hundreds of kilometers per second, from a star. protostar — a very young star still in the process of formation, before nuclear fusion begins.
Worked example
What does “giant molecular clouds” mean in The Birth of Stars and the Discovery of Planets outside the Solar System?
- 1Use the wording this chapter gives for giant molecular clouds.
- 2The book says: large, cold interstellar clouds with diameters of dozens of light-years and typical masses of 10 5 solar masses; found in the spiral arms of galaxies, these clouds are where….
- 3Do not use the meaning of most well-studied molecular cloud. That term means Orion, where star formation is currently taking place.
Result: large, cold interstellar clouds with diameters of dozens of light-years and typical masses of 10 5 solar masses; found in the spiral arms of galaxies, these clouds are where…
Why. That is the meaning this chapter gives for giant molecular clouds.
Do not swap giant molecular clouds and most well-studied molecular cloud. giant molecular clouds means large, cold interstellar clouds with diameters of dozens of light-years and typical masses of 10 5 solar masses; found in the spiral arms of galaxies, these clouds are where…. most well-studied molecular cloud means Orion, where star formation is currently taking place.
Practice margin
This chapter
A fresh set from this chapter only. Choose 10 or 20. Multiple choice and fill-in, with no repeat inside the set.