At this moment, the closest star to Xiao Yu was Star C. Its color was yellow-white, indicating a surface temperature higher than that of the Sun. Correspondingly, its mass was also greaterâabout 1.8 times the mass of the Sun.
Depending on surface temperature, stars present different colors, ranging from low to high: red, yellow, white, and blue. Generally, the higher a starâs surface temperature, the greater its mass, though this isnât absolute. For instance, red giants also appear red, yet they are many times larger than red dwarfs. Their red color is due to entering the final stages of stellar life, where their volume expands and temperature drops.
Star C was a yellow-white starâthe largest in the Aquila IV system. Currently, the poor little planet orbited around it. Xiao Yuâs destination was this very star.
Normally, planetary orbits around a star are predictable. Take Earth: its distance from the Sun at any given point in the year is nearly constant, leading to a stable orbit. But this planet was different. At the same point in its orbit, it could be found in wildly different positions from one cycle to the next. That meant its orbit was extremely unstable. It wasnât like a proper planetâit was more like one of those errant comets drifting in from interstellar space.
Clearly, this instability was caused by gravitational perturbations from the other stars in the system. The disruptions were so severe that the planet frequently changed its host star.
Xiao Yu had begun observing the planet a full year before arriving at Aquila IV. Over that year, the planet had switched host stars six timesâan average of once every two months. Its orbital instability was evident.
Only after entering the vicinity of this quintuple star system did Xiao Yu begin to grasp its strangeness.
Since thereâs no diffuse scattering in the vacuum of space, all celestial objectsâbe they planets or spacecraftâhave a clear light/dark divide when near a star. The side facing the star is day; the far side is night. But not here. In this system, there was no such thing as night. No matter the angle, front or back, Xiao Yuâs fleet was lit up by starlight.
As Xiao Yu gathered data from the stars, he continued his approach. Now, he was just 300 million kilometers from the planet.
He had fully entered the interior of the Aquila IV system.
At this distance, Xiao Yu suddenly observed all five stars flash simultaneously. In that instant, the positions of the five stars shifted by about 0.3 degrees. But in the very next moment, they returned to normalâas if the shift had never occurred.
The phenomenon immediately put Xiao Yu on high alert.
âWhat happened? Can they teleport?â Xiao Yu frowned, retrieving all observational data from that moment and analyzing it in detail.
But the results only deepened his confusion. All parametersâmass, luminosity, orbital dataâappeared completely normal. This made him question whether his instruments had malfunctioned.
Yet he quickly dismissed the thought. A single instrument failing could be explained. But for thousands of devices to simultaneously malfunction? The odds were astronomically low.
Xiao Yuâs pulse quickened with excitement.
âThis phenomenon⊠I canât explain it yet. But the girlâs diary did say the Grand Unified Theory was hidden somewhere in this system. Could this bizarre phenomenon be related to it?â
It was the most plausible explanation.
âAt present, I donât know what causes this effect or how it operates. But if I stay here long enough, Iâll figure it out. If I can explain this phenomenon, I might be very close to grasping the Grand Unified Theory.â
Xiao Yu grew more energized. The unknown wasnât terrifyingâit was failing to discover the unknown while believing you had mastered everything. Just like during Newtonâs time: people thought they had fully grasped the workings of the universe through the three laws of motion. Using them, they even discovered Uranus and Neptune. As a result, scientific progress stalledâuntil Einstein and other geniuses identified new phenomena, researched them, and proposed new theories. Only then did humanity leap forward into the atomic age.
Quantum mechanics and relativity had both emerged from that eraâdriving humanity to explore the unknown and acquire more knowledge.
Xiao Yuâs ship steadily approached the planet and entered orbit.
Up close, Xiao Yu got a clear view of its surface.
A smooth, black crystalline terrain. There were no significant elevations, no mountains, no valleys.
âTruly pitiful,â Xiao Yu murmured, his sympathy for the planet rising.
Its surface conditions clearly spoke of prolonged torment. The black landscape was composed of once-molten rock. It wasnât hard to imagine: time after time, it had drifted near a star, only to be scorched by immense stellar heatâmelting the surface rockâthen cooled and solidified as it drifted away, only to be melted again next cycleâŠ
In this cycle of melting and solidifying, all geological detail had been erased.
It had no atmosphere. Even if it once had one, it had long since been stripped away by relentless solar bombardment. Now, it lay just 50 million kilometers from Star Câless than half the Earth-Sun distance. And given Star Câs activity exceeded the Sunâs by a large margin, even Earthâs atmosphere would be stripped away in a million years at this range.
Under the light of Star C, its surface temperature reached 400°C. At this temperature, its rocky terrain emitted a faint red glow, like a terrifying hell of molten lava.
Besides Star C, Stars D and E were also not farâ170 million and 200 million kilometers away. From this planetâs surface, Star C looked as large as a millstone, dozens of times brighter than the Sun. Star D appeared basketball-sized, slightly dimmer than the Sun. Star E resembled a soccer ballâfaintly red and only one-tenth as bright as the Sunâbut still a thousand times brighter than a full moon.
Three stars illuminated this hellish world.
The rear side of the planet was even more surreal. It was tidally locked to Star C, meaning it always faced that star with the same side. On its far side, 770 million and 800 million kilometers away, were Stars A and B. From that distance, they shone with brightnesses tens to hundreds of times greater than a full moon, bathing the surface in a dusky golden hueâsimilar to twilight on Earth. Anyone reading a book here wouldnât need additional light to see the words.
The night-side temperature hovered around 10°C.
This was the world where Xiao Yu intended to settle.
âThe environment isnât great⊠Iâll just have to make do,â he thought with a wry smile.
Compared to the Aquila three system and the Arrow Beast homeworld, this place was a far cry from livable.
But here, Xiao Yu began his preparations.
First, a large particle collider was essential. But placing it in orbit around a star would be inappropriate. So Xiao Yu opted to scale it down and have it orbit the planet instead. Next, aside from researching unknown phenomena, he also planned to continue upgrading his fleetâso massive shipyards were a must.
Since there were no gas giants here, acquiring fuel was a problem. To address this, Xiao Yu had to conduct mining surveys on the planet to extract nuclear fission fuel as a replacement for fusion fuel.
In Xiao Yuâs plan, fusion fuel was emergency-only. Energy in the Aquila IV system would come mainly from solar and fission sources.
To gather enough construction materials, he also had to build underground bases to shield against stellar heatâfurther increasing the workload. But Xiao Yu wasnât in a hurry. Cracking the Grand Unified Theory was a long-term endeavor, and he had no illusions of a quick breakthrough.
After launching several satellites for geological exploration and gaining detailed planetary data, Xiao Yu deployed heavily modified robots to the surface and began building his base.
Amidst this flurry of activity, Xiao Yu didnât neglect observation of the five stars.
Three days after arriving, he once again witnessed the strange stellar shift phenomenonâthis time, from the planetâs night side.
Two huge, bright âmoonsâ suddenly vanished from Xiao Yuâs viewâreappearing in slightly different positions, about 0.6 degrees offset. The shift lasted about 1/3000 of a second before returning to normalâas if nothing had ever happened.
âItâs happening againâŠâ Xiao Yuâs eyes lit up with excitement.