Key Terms
- exoplanet
- a planet orbiting a star other than our Sun
- giant molecular clouds
- large, cold interstellar clouds with diameters of dozens of light-years and typical masses of [latex]{10^5}[/latex] solar masses; found in the spiral arms of galaxies, these clouds are where stars form
- Herbig-Haro (HH) object
- luminous knots of gas in an area of star formation that are set to glow by jets of material from a protostar
- mini-Neptune
- a planet that is intermediate between the largest terrestrial planet in our solar system (Earth) and the smallest jovian planet (Neptune); generally, mini-Neptunes have sizes between 2.8 and 4 times Earth’s size
- protostar
- a very young star still in the process of formation, before nuclear fusion begins
- stellar wind
- the outflow of gas, sometimes at speeds as high as hundreds of kilometers per second, from a star
- super-Earth
- a planet larger than Earth, generally between 1.4 and 2.8 times the size of our planet
- transit
- when one astronomical object moves in front of another
This book was adapted from the following: Fraknoi, A., Morrison, D., & Wolff, S. C. (2016). Key Terms In Astronomy. OpenStax. https://openstax.org/books/astronomy/pages/21-key-terms under a Creative Commons Attribution License 4.0
Access the entire book for free at https://openstax.org/books/astronomy/pages/1-introduction
