Categories of Objects in Space Part 2: Reflection Nebula

Because astronomy is an observation-based science, we need to carefully categorize the objects we see. As we explore the cosmos, we discover that not all objects are the same, and even then, some objects that appear the same at first glance differ greatly in the details. Here, we will be discussing the classifications we give the o
bjects we find.

A nebula is basically a large cloud of gas – in that, there are several different categories that define the type of nebula we are viewing.

Today, I wanted to talk about reflection nebulae.

A reflection nebula is a nebula that reflects the light of a nearby star or star cluster. Unlike an emission nebula, this nebula is not ionized. Instead, it scatters the light it receives in a brilliant and visible way. It isn’t uncommon for reflection nebula to be comprised of carbon compounds (like diamond dust), iron, and nickel.

Most reflection nebulae are blue simply because blue is the most efficient at being scattered. It isn’t uncommon to see reflection nebulae and emission nebula in the same region. One of the most famous reflection nebulae is the Witch Head nebulae as seen below.

The Witch Head Nebula (pictured here) is about 900 light-years away in the constellation Orion. Obviously, the Witch Head is the nebula seen near the lower left of the image. Rigel, as you might have already guessed, is the very bright star seen to the right of the Witch Head near frame center.

References, sources, and further reading can be found here: http://www.fromquarkstoquasars.com/categories-of-objects-in-space-part-2-reflection-nebula/