The celestial nexus (also known as the Glow nexus) is a biological network that lies just below the skin of Glowcreatures. The nexus facilitates the transportation of Aura in and out of the Glowcreature's body. It also helps to store small amounts of Aura.
The Glow nexus spreads over nearly the entire body, just under the skin. It has an appearance similar to the nervous system, with branching tendrils that end either near the outer surface of the Glowcreature or somewhere within the body. The endings of nexus tendrils are called nexus nodes. These nodes are tiny and numerous, with upwards of 200 nodes per square inch of skin.
Two types of nexus nodes exist: input and output nodes. Input nodes are responsible for absorbing Aura from the surrounding environment and passing it further into the nexus, where it is transported to the bloodstream for use elsewhere in the body. In Glowcreatures with a Celestial Core, the Aura is transported there for storage.
Input nodes are spread all over the body just under the surface (in mammals, this is the dermis). They are more frequent in areas that are likely to receive large amounts of Aura. For instance, a quadrupedal Glowcreature will likely have many input nodes along their back, but only a few along their stomach. Input nodes are much more numerous than output nodes. They are never found very deep inside the body.
Input nodes gather Aura passively. More intelligent Glowcreatures are able to stimulate their nexus to prompt the input nodes to suck in Aura faster than normal. It's possible to overextend and draw in too much Aura too quickly, which can result in pain, Blood Burn, or even Combustion. Glowcreatures with purely passive nodes are also in danger of these conditions if they stay out in an Aura field for too long, since they are incapable of directly stopping their Aura intake.
Output nodes are responsible for discharging Glow. They can exist outside or inside the body. Glowcreatures that use Glow completely internally only have output nodes within their body, and are almost never able to consciously control the rate of output. Glowcreatures of this kind are often less intelligent species that also lack celestial cores.
When output nodes are present near the surface of the creature, they're capable of discharging Glow into the surrounding environment. They are also only active with conscious thought, and never "leak" unless the Glowcreature has some sort of condition. External output nodes are only present in large quantities in areas of the body where it is easiest or most useful to discharge Glow. In humans and lilthians, these are the hands. These locations are called "focus points", or "celestial focuses".
Often, focus points will have some sort of edylium body part connected to or on top of the focus spot. These body parts further magnify the power of the animal's Glow discharges. Unicorns are an excellent example of this. They have a very high concentration of output nodes underneath their horn--which is made almost completely of edylium--allowing them to discharge massive amounts of Glow from a specific location.
History and Culture
The celestial nexus was only recently discovered. For a long time, it was the general belief that the celestial core was the driving force behind all Glow functions. When it was realized that not all Glowcreatures have cores, there needed to be another explanation for how they were able to use Glow. The nexus was discovered through the dissection of dead specimens. It had managed to go unnoticed thanks to its small size and strong resemblance to the nervous system.
The discovery of the nexus lead to a leap in the understanding of Glow. It provided clarity on how exactly Glow moved from the core elsewhere. It also explained why it was so much easier to discharge Glow from one's hands as opposed to anywhere else.
Culture and Perception
Even though the nexus is closer to the surface of the skin than the veins, the sensation of absorbing Glow often feels as if the energy is flowing into one's blood. This feeling perpetuates the myth that the blood itself is what facilitates the transportation and use of Glow. The nexus was also once believed to be filled with an alternate liquid to blood and functioned as a second network of blood veins and vessels.
These beliefs, although debunked, are the foundations to many cultural interpretations of the nexus and the use of Glow. It is commonly related to life force, since losing one's blood (the perceived carrier of Glow) means certain death.
PurposeAbsorption and transportation of Aura in and out of the body
Organ that allows active consumption of Celestial Aura