Death From Above

Epsilon Aurigae and Zeta Reticuli

posted on 11/2016   By: Dave Schalek

Doom. Monolithe has always been on my radar for its references to astronomy, whether it occurs in cover art, theme, or in song or album title. The last two full-lengths, Epsilon Aurigae and Zeta Reticuli, are named after two stars. Each star is interesting for different reasons.

Epsilon Aurigae was first noticed in the 19th century as a very long period variable star. It is located in the bright, northern hemisphere constellation of Auriga and is a blue-white star larger and more luminous than the Sun. It's about 2,000 light years away.

However, inexplicably, the star dims by over three orders of magnitude for a couple of years at a time once every approximately 27 years. This type of behavior for a main sequence star is unusual, as main sequence stars don't show this tye of extreme variability in luminosity.

The main sequence refers to a tool in astronomy called the Hertzsprung- Russell, or HR, Diagram. The HR Diagram graphically explains the life cycles of stars of different masses, and the main sequence refers to a portion of the graph where a star spends most of its lifetime, fusing hydrogen into helium. This is a period of stability in a star’s lifetime. For example, the Sun is a main sequence star; albeit, smaller and less luminous than Epsilon Aurigae, and is about halfway through its time on the main sequence.

The history behind the study of Epsilon Aurigae is a fascinating one. The last such dimming event, which ended in 2011 (side note: Monolithe's Epsilon Aurigae was released in 2015 through Debemur Morti Productions), provided a treasure trove of telescopic observations. NASA's Spitzer telescope, in particular, confirmed the prevailing theory explaining Epsilon Aurigae’s odd behavior.

Epsilon Aurigae is being eclipsed by an enormous disk of dusty material in orbit about the star. The disk itself has a hole, sort of like a doughnut, that’s been cleared of material by a smaller star within the hole.

Essentially, Epsilon Aurigae is a binary star system with the smaller companion star locked in orbit about the primary, while surrounded by a dusty disk of material left over from its own formation. The disk is oriented with respect to us nearly edge on. 

The disk with the companion star is about as far from the primary star as Neptune is from the Sun within our own Solar System. Epsilon Aurigae is a rather unique system, one that is altogether fitting as a theme.

On the other hand, Zeta Reticuli is most famous for being the fictional setting of the moon LV-426 depicted in Alien and Aliens. Located in the southern constellation of Reticulum, Zeta Reticuli is actually a wide binary system consisting of two stars similar to the Sun (but younger), orbiting each other with a period of 170,000 years. The two stars are very far apart at about 3750 AU (an astronomical unit, or AU, is the average distance of the Earth from the Sun, about 93 million miles); hence, the long orbital period.

One of the stars, Zeta 2, is noteworthy for having a disk of debris in orbit at a distance of only a few AU. The disk’s shape indicates that it might be gravitationally perturbed by an as yet unseen gas giant planet similar in size to Jupiter. This hypothesis has not been observationally confirmed, but the gas giant’s hypothetical existence fits in nicely within the story confines of Alien, which shows the Nostromo approaching a gas giant with a family of moons near the beginning of the film. Zeta Reticuli is relatively nearby at a distance of 39 light years.

I wouldn’t want the xenomorphs any closer.