What is the best description of what a planetary nebula is?

Similarly, what causes a planetary nebula?

A planetary nebula is created when a star blows off its outer layers after it has run out of fuel to burn. These outer layers of gas expand into space, forming a nebula which is often the shape of a ring or bubble.

Furthermore, how bright is a planetary nebula? Planetary nebulae are considerably denser than most H II regions, typically containing 1,000–10,000 atoms per cubic cm within their dense regions, and have a surface brightness 1,000 times larger. High-resolution images of a planetary nebula usually reveal tiny knots and filaments down to the resolution limit.

Similarly, it is asked, what is a planetary nebula quizlet?

Planetary Nebula. A shell of gas from stars like our sun, at the end of their lifetime, there is no materials and they need to form a new star. main sequence to red star.

What causes a planetary nebula quizlet?

Planets engulfed in the flame of a red giant continue their orbit inside the star, churning it up and causing material to be ejected irregularly. When the Sun dies it will most likely become a planetary nebula but it will be much smaller than most we can currently see from Earth.