100th Millennium Wiki

The Treana System is a high-mass close trinary system in the Florathel Galaxy, composed of two massive Wolf-Rayet stars and an O-type star. The system has existed for less than two million years, and is located at the dead center of the Treana Molecular Cloud Complex, in the Sapphire Cluster.


This trinary system is probably one of the most massive and energetic systems in the galaxy, residing in the Treana Molecular Cloud Complex and fueling its star formation. Treana contains the second most massive star in the entire galaxy (Treana Aa), at a whopping 148.2 Stellar Masses.

The extreme luminosity of this star system made the Telusian Civilization build several SICTIRIAD stations surrounding the system shortly before its demise. The Areial Union has been at work repairing these stations, and Treana will likely soon become a hub of commerce, given the high HDI of this system.

An extremely large dyson sphere surrounds this star system, and is constantly under maintenance from the deadly solar winds emanating from the three stars. Owing to the constant repairing, it is not as safe to be around these spheres and they are home to obscure gang-esque groups which have caused repeated instability around the area. Fortunately, nothing like this has been found in or near the SICTIRIAD stations.

The luminosities of the stars:

Treana B: 2130000 LSol

Treana Aa: 1313000 LSol

Treana Ab: 738000 LSol

Combined: ~4.2 million LSol

Orbital Characteristics

The Treana System is noteworthy as it is extremely tightly bound for a system with stars this massive. As a result, Treana Aa and Ab have a separation of only four Treana Aa radii, and the pair orbits around their barycenter around every 6.85 days. The separation between Treana Aa-Ab and B is only 3.5 AU, and because of the large masses involved, the system only takes 143 days to complete an orbit.

Physical characteristics

Out of the three, Treana B, also nicknamed Enirepa, is the most massive. It has a mass of almost 150 stellar masses, astonishingly large for any kind of star. It is in fact the second most massive star in the entire Florathel Galaxy. Because of this, it and Treana Aa are already wolf-rayet stars. Treana B's initial mass was around 190 stellar masses, and it is also the largest of the three stars, being around 30 times the radius of the sun.

Treana Aa, also dubbed Traiteni, is the second most massive (~76.2 stellar masses) and is also a Wolf-Rayet star. Its initial mass was around 100 stellar masses.

Treana Ab, known as Uresie, is the least massive star and is what is known as a Slash Star, a rare form of "main-sequence" star which is about to become a Wolf-Rayet, and is around 49.4 stellar masses in mass. It is the smallest of the three stars.

The Treana System is often considered a more extreme form of Plokeon, another binary system with a wolf-rayet star and a slash star.


The Treana system only formed 1.9 million years ago, and is a very young star system. The Treanan stars formed much farther apart than they currently are, being formed in two separate systems, (3 light years apart when they first formed) one containing the single Treana B (Enirepa) and the other, the close Treana A binary. The reason that they are now a binary is that both Treana systems (A&B) formed in a dense star cluster, and stellar interactions were common. So Treana A managed to pull Treana B into a relatively distant orbit, both separated by around 620 AU. But, other stars were everywhere.

Around 61,000 years after this happened, a 26 stellar masses late O-type star passed very close to the Treana system and took some of Treana A's velocity, leading to that star, now known as the hypervelocity star Eimvas, to be slingshotted out of Treana's home cluster and into interstellar space at a high velocity. Treana A and B were now separated by just 27 AU.

At this point, the stars were just 310000 years old, all very young O-stars at the time (O2V, O3V and O4V) which were still burning hydrogen in their cores. However, a significant amount of nitrogen was quickly accumulating in the envelope of Treana B (The most massive of the three), and due to convection, the ionised nitrogen rose up to the surface, leading to a f in its spectral type. The powerful solar winds of the three stars also were slowing down their speeds and consequently shrinking their orbits. Everything pretty much continued evolving for the next few hundred thousand years.

Around 900,000 years ago, Treana B expanded and cooled, turning into a Luminous Blue Variable, albeit quite a hot one (around 35000 K) As soon as it did so, its stellar wind increased 100-fold, quickly withering the Treanan trajectories until the stars were just 4 AU apart, a drastic change. During this, Treana B also released a huge outburst (~10 stellar masses) which turned into a bubble nebula surrounding the system and later ionised by the Treanan stars' powerful solar winds.

Treana B, now with just 155 stellar masses left, is now a WNh star, the most massive kind of Wolf-Rayet star. It shines with over 2 million solar luminosities and is well within the top 50 most luminous stars in the galaxy. Treana Aa, now also a Wolf-Rayet star due to enrichment of ionised nitrogen, and shines with slightly over 1.3 million solar luminosities, also very bright. Treana Ab, however, is still in the main sequence and on its way to become a blue/red supergiant, where it will likely lose all of its outer layers quickly and become a typical, hydrogen-free Wolf-Rayet star, unlike the other two. It currently shines with about 740 thousand solar luminosities, still very very bright.

Predicted Future

In around 100,000 years, it is predicted that Treana Ab will start to expand as it leaves the main sequence, where it will likely overfill its roche lobe and possibly touch Treana Aa and make a contact binary (Blue giant+WR contact binary) and if it does so, the resulting binary will be very very rare.

In around 300,000 years, it is predicted that Treana B will explode as a supernova (probably leaving a massive black hole behind), having lived a life lasting merely 2.2 million years, leaving Treana A adrift in interstellar space, and possibly speeding the contact binary to hypervelocity speeds.

What the future Treana A binary may look like, with hypervelocity two Wolf-Rayet stars orbiting each other.

In around 450,000 years, it is predicted that Treana Ab will completely engulf Treana Aa, that is if its outer envelope is still intact. It likely will not be, because Treana Aa's solar wind and tidal forces will have ripped it off Treana Ab, exposing its hot core, which will likely be no different from a Wolf-Rayet star. If this does indeed become reality, lifeforms hundreds of thousands of years in the future will witness a hypervelocity double Wolf-Rayet star (One hydrogen-rich, the other hydrogen-free), likely one of the rarest sights in the universe. It is slightly unclear whether the WR Treana Ab will be classified as WN, WC or WO, but the research is leaning towards a WN classification.

By 2.5 million years in the future, Treana Aa will have exploded in a supernova, possibly leaving Treana Ab to roam free in interstellar, or maybe intergalactic space. It will continue to shrink, heat up and fuse, possibly gaining a WO spectral class. 3.5 million years in the future, Treana Ab will finally go, likely in a gamma-ray burst, ending the great story of the most massive trinary system in the Florathel Galaxy.