Nephthys was known as The Lady of the Temple:

Unlike the virile Isis, Nephthys was a barren goddess who symbolised death. Even in the Pyramid Texts she was an enigmatic presence. Yet despite her ominous nature, she was viewed as a morbid-but-vital force of heavenly rejuvenation. In fact, Nephthys was the opposite of Isis in every respect. Isis symbolised rebirth, growth and development while (the Black Isis) Nephthys implied death, decay and diminution. The Pyramid Texts of Unis echo this:

You will go up and go down: you will go down with Nephthys, one of the dusk with the Nightboat. You will go up and go down: you will go up with Isis and rise up with the Dayboat.

A solar ship was a mythological representation of a sun riding in a boat. These craft were also called “solar barks” or “sun boats.” In the picture below, we see Osiris riding in one such vessel flanked by Nephthys and Isis.

If Nephthys was a neutron star then she illustrated death perfectly. In scientific terms her core burned to iron long ago, energy production ceased and she collapsed. This squeezed electrons and protons together to form neutrons and neutrinos. As she moved away from the main sequence, subsequent nuclear burning produced an iron-rich core. When all nuclear fuel had been exhausted, her core was supported by degeneracy pressure alone. As a stellar corpse, Nephthys is still positioned at the centre of this system because of her incredible density.