Kerillis Nebula

Telescope image of the Kerillis Nebula

The Kerillis Nebula, also known as the Erian Nebula, the Great Nebula in Erian, and NSC3319, is the second largest single object in The Silky Way.

## Physical Characteristics

The Kerillis Nebula is plainly visible in the night sky of most planets in the near galaxy, even in places with some light pollution. It is seen as the middle star in the belt of the ancient Terallan constellation of Erian.

The Kerillis Nebula is the largest nebula in the galaxy. It contains approximately 200,000 stars in it, and is the densest region in the Silky Way's ring and the second densest region in the galaxy. It has many large clusters of stars and an extreme overabundance of large stars, which causes the nebula to glow a pretty blue color.

### Parallelogram Cluster

The Kerillis Nebula has a large cluster of stars, known as the Parallelogram Cluster, which is dominated by Kerillis. It is a dense region of the greater Kerillis Nebula Cluster, which is spread out through most of the Kerillis nebula.

#### Notable Members

* Kerillis
* Hadra
* Smizzok
* Goontoolmoon (who named *that*?)
* Dran (binary black holes)

### Triangle Cluster

Another dense region of the Kerillis Nebula is the Triangle Cluster, which is mainly composed of lower mass stars, the largest star being Rigela at 8.5 solar masses.

Has anyone noticed how a lot of these clusters are named after geometric shapes?

#### Notable Members

* Rigela
* Athos (Habitable System)
* Anhooie (Habitable System)
* Raga
* Hydra (Habitable System)
* Pegani
* Voyorr

## Coloration

The Kerillis Nebula has a distinctive blue color, because of the sheer amount of light emitted by the largest stars. However, in places, it has a strange green tint. After a lot of head scratching by top astronomers, they found that this was "a low-probability electron transition in doubly ionized oxygen, a so-called forbidden transition". This explanation has triggered yet more head scratching among people who are not top astronomers as they try to figure out what the hell that means. This is nearly impossible to reproduce in the Lab™, because it depends on the quiescent and nearly collision free environment in deep space.

## Star Formation

The Kerillis nebula is the largest known example of a star forming region in this galaxy, though it is smaller than the Madhe Nebula, in the Kraltuir Galaxy

Approximately 10 stars form per year in the Kerillis Nebula, approximately on par with the Apple Nebula's star formation rate. However, a similar number of brown dwarfs and even more sub-brown dwarfs form over the same timeframe.

### Stellar Wind and Effects

Once formed, the stars within the nebula emit a stream of charged particles known as a stellar wind. Massive stars and young stars have stronger stellar winds than the Sun or Verda. This wind forms shock waves when it encounters gas in the nebula, and this in turn shapes the gas of the nebula, forming it into pretty shapes and triggering collapse in some areas, forming sterrs.

There are four different kinds of shocks in the Kerillis Nebula. Many are features in Herbig-Haro Objects.

* Bow shocks are stationary and are formed when two particle streams collide with each other. They are present near the hottest stars in the nebula where the stellar wind speed is estimated to be thousands of kilometers per second and in the outer parts of the nebula where the speeds are tens of kilometers per second. Bow shocks can also form at the front end of stellar jets when the jet hits interstellar particles.
* Jet-driven shocks are formed from jets of material sprouting off newborn T-Tauri stars, like Klein. These narrow streams are traveling at hundreds of kilometers per second, and become shocks when they encounter relatively stationary gases.
* Warped shocks appear bow-like to an observer. They are produced when a jet-driven shock encounters gas moving in a cross-current.
* The interaction of the stellar wind with the surrounding cloud also forms "waves" which are believed to be due to the Hydrodynamical Kelvin-Helmholtz Instability™, which has apparently been trademarked by some rich corporation.

## List of Members

### Parallelogram Cluster

* Kerillis
* Hadra
* Smizzok
* Goontoolmoon (who named *that*?)
* Dran
* Alanis

### Triangle Cluster

* Rigela
* Athos
* Anhooie
* Raga
* Hydra
* Peganis

## Trivia

* The Kerillis Nebula is the largest single object in The Silky Way.
* It forms a lot of stars and looks rather pretty.