Death of a Neutron Star

by Eric Kotani

  “I don’t think she’s too happy with that order, Captain,” Chakotay said, smiling, as Janeway slumped down into her command chair and stared wistfully at the empty coffee cup.

  “Put a security detail near her quarters, but not close enough to be obvious.”

  Chakotay turned to follow her order.

  “And one more thing,” she said, staring at the warp images flashing past on the front screen.

  “Yes, Captain,” Chakotay said.

  “I think we both need a cup of coffee.” She smiled.

  Chakotay laughed softly. “I’ll see what Neelix has left.”

  “Thanks,” Janeway said. She sighed, rested her chin on her hand, and looked out at the starscape that lay ahead.

  CHAPTER 3

  SINCE THERE WAS OVER A DAY UNTIL THEIR ARRIVAL AT the binary star system, Neelix suggested he serve a late lunch first for the officers and the ship’s guests. Janeway had figured it wouldn’t hurt, and would even give her a little time to get a better sense of the truth of their story. And maybe find out that last detail Dr. Maalot seemed to be hiding.

  Now Neelix buzzed around the two Lekks like a mother hen over her chicks. “Don’t be shy, friends,” Neelix said, putting more food on Dr. Maalot’s plate. “There’s more, a lot more, where this comes from.”

  Neelix had seated them all at the same table, with Tyla and Maalot to Janeway’s right, Chakotay, Tuvok, B’Elanna, and Paris around the rest of the table. They were the only ones in the mess hall and the meal seemed to go well, as far as Janeway was concerned. But the conversation was purely social. It was time to get down to business.

  “Doctor Maalot,” she said, “would you mind fielding a few more questions from my officers about the neutron stars?”

  Maalot, who had been fiddling around with the last of his pastry with a fork, smiled, then glanced around at the others. “Most assuredly, Captain.”

  The Lekk astrophysicist seemed almost beside himself to have the opportunity to elucidate on his favorite subject. “Let me begin with the construction of the star.”

  “The nuclear degenerate matter in a typical neutron star is so densely packed,” he said, holding his palms together to illustrate, “that electrons are pushed into protons, turning them into neutrons. Since the star is basically made up of neutrons, instead of all sorts of atoms, as is the case with normal stars, it is called a neutron star. Under these conditions, the density of the matter is a few billion tons per cubic centimeter, which is about the size of a sugar cube. This may sound counterintuitive, but a neutron star with smaller mass is in fact larger in size than a more massive one.”

  Janeway was surprised the doctor had said all that without even taking a breath. She glanced at Tom. Clearly, the good doctor had almost lost him in the first sentence. Starfleet had required all its officers to take basic astrophysics classes, but they weren’t pushed much for pilots.

  “I understand that a neutron star’s mass is not so different from that of an ordinary star,” Ensign Kim said. “But practically every book and article I’ve read about neutron stars mentions the destructiveness of the tidal force in its vicinity. Why?”

  Janeway almost wanted to laugh as Maalot beamed the smile of a happy professor fielding questions from a bright student. “An excellent question! The strength of a gravitational field is in proportion to the total mass of the gravitating body, but it is also inversely—note ‘inversely’—proportional to the square of the distance from it.”

  Paris’s eyes widened in confusion and anxiety.

  B’Elanna smiled and patted his hand, but Tom ignored her.

  Dr. Maalot kept smiling, but nodded. “I’m sorry. Let me put it this way. A neutron star is typically only about ten kilometers in radius—in contrast to the radius of a main-sequence G-type star, whose radius is measured upward of a million kilometers. Thus, an object can get quite close to that great mass of a neutron star. Closer than a ship could ever go to a normal star.”

  “Which then makes the gravitational force a ship experiences even more tremendous,” Janeway said.

  “Exactly,” Maalot said. “What’s more, the tidal force increases in inverse proportion to the cube of the distance from the center of the mass. Thus, any ordinary matter approaching a neutron star too closely would be ripped apart by the inexorable tidal force in its proximity.”

  “Almost before it knew what hit it,” B’Elanna said.

  Tom looked even more puzzled. “Put it this way,” Janeway said. “Even if a ship were made of a mythical, indestructible unobtanium, it and everything and everyone inside the ship would be torn apart at a molecular level if the ship went too close.”

  Even Kim was starting to look perplexed now. “Ensign, you’re not following this?” Janeway asked.

  “No, I understand,” Kim said, “but how can you have a binary neutron star system? It seems to me that one companion, or the other—possibly both—would be torn apart by the tidal force of the companion.”

  “Another good question,” Dr. Maalot said, again smiling. “Theory is that neutron stars are so tightly bound by their own formidable gravitational field that they can orbit around each other forming a binary pair without being torn up by the other.”

  “Their intense gravity serves to hold them together,” Janeway said.

  “Exactly,” Dr. Maalot said.

  Kim nodded.

  “But only up to a certain point of proximity,” Dr. Maalot said. “When the two stars are nearly in contact with each other, all hell can, and does, break loose.”

  “Like any two colliding stars,” Paris said.

  “No,” Dr. Maalot said. “Much worse.”

  “Not even on the same scale,” B’Elanna said.

  Janeway nodded. “You have to understand how a neutron star is formed. They are the final stage in the evolution of massive stars, usually formed in the collapsing core of a supergiant after the star has exhausted its fuel. The colossal amount of energy released in such a core collapse propels the enveloping atmosphere explosively away.”

  “So, basically, this is a supernova,” Chakotay said.

  Janeway nodded.

  “And that leaves a neutron star in its place?” Tom asked.

  “Exactly,” Janeway said.

  “Got it,” Paris said.

  Janeway glanced around. Kim nodded. Dr. Maalot gestured for her to continue. “A neutron star might also be formed, if a white dwarf star becomes too massive by accreting matter from a companion, and exceeds the upper mass limit for a white dwarf. It would then collapse under its own weight and become a neutron star.”

  “Was that how this binary was formed?” Paris asked.

  The doctor shrugged. “We can’t say for sure how this particular pair came into being. In fact, we have little idea how such a pair would ever form.”

  Janeway nodded. “One of the rarest things in all the universe.”

  “So,” Kim said, “why is, as you put it, all hell going to break loose?”

  Dr. Maalot actually laughed. Janeway watched as Lieutenant Tyla just frowned. She had heard all of this before and was apparently trying to tune it out.

  Neelix refilled Janeway’s cup of coffee again, and she smiled at him.

  “A neutron star can lose matter from its surface under the powerful gravitational influence of another neutron star,” Dr. Maalot said.

  Kim nodded. “I understand that.”

  “Good. When the two neutron stars get very close to each other, one star’s mass could become small enough that it is no longer massive enough to keep its neutron matter in that highly condensed nuclear degenerate form. Destabilized gravitation-ally, the whole star will explode with a force that is comparable to a small supernova.”

  “Just how energetic an explosion is a supernova?” Kim asked.

  “Best way to explain it is this,” Janeway said. “In a typical supernova explosion, energy equivalent to the ordinary radiation from billions of stars is released. That energy is so incompreh
ensibly immense, even a small percentage of it—as would happen in the explosion of such an underweight neutron star—is still a cosmic cataclysm.”

  “Does that mean the planetary system of Dr. Maalot and Lieutenant Tyla is doomed?” Paris asked.

  Janeway glanced at Dr. Maalot while shaking her head. He also was shaking his head.

  “Not necessarily,” he said. “Not even probably, at least from the initial explosion. Any planetary system located within a light-year or so of the mini-supernova would be in serious trouble. First, at such a proximity the planet would be exposed to an intense high-energy radiation that would harm animal and plant life. Any technological society would suffer from the electromagnetic pulsation effects precipitated in the atmosphere by the gamma-ray bursts; the EMP effects would shut down all unprotected electronics.”

  Janeway agreed, but she knew that wasn’t all that would happen. “A planet within a light-year would also be hit by a wave of highly energetic plasma. It would be devastating.”

  “Fortunately,” Dr. Maalot said, “our system is just over ten light-years away, where the supernova blast will be considerably diluted. The Lekk world will likely survive the calamity, although there may be some unavoidable damage to our ecological system.”

  “So, the main danger to your system, Doctor,” Janeway said, “involves the direction that the runaway neutron star will take. Am I correct?”

  “You are entirely right, Captain. The chances that the runaway star will destroy any particular solar system within ten light-years—by a random chance of the timing of the explosion—are not very high.”

  “But actually,” B’Elanna said, “the runaway star doesn’t need to go through the center of a system to destroy it.”

  “Correct,” Dr. Maalot said. “Simply by passing too close, the massive object would alter the planetary orbits so much that the solar system would become uninhabitable. Even with that, the chances for serious calamity on the Lekk planetary system are less than one in a thousand.”

  “Little comfort to your people, I’ll bet,” Paris said.

  “You’ve got that right,” Tyla said, speaking for the first time in a while. She stretched her long arms. “Doctor, don’t you think it’s about time you tell these people the real problem? Tell them why I need to get home and warn our people.”

  Janeway glanced at Tyla, then at Dr. Maalot. It was a good thing the young lieutenant had a lower tolerance for keeping secrets than her companion. It was indeed, about time that Voyager’s guests laid their cards on the table.

  The doctor looked almost uncomfortable. His green eyes stared down at his coffee cup. After a long moment he spoke without looking up. “We overheard a plan to force the neutron star explosion and send the rogue neutron star into our system.”

  “What?” Janeway said.

  “That’s not possible,” B’Elanna said.

  “I agree,” Dr. Maalot said. “I don’t think it is possible.”

  “But that is the Qavoks’ plan,” Tyla said.

  The stunned silence filled the room. There was nothing more to say. There was nothing more Janeway could think of to say. What he had suggested was plainly impossible.

  Yet the Qavoks seemed to think they might be able to do it.

  Impossible.

  Yet …

  CHAPTER 4

  WHEN THE LUNCHEON WAS OVER, JANEWAY, WITH B’Elanna, escorted Dr. Maalot down to the laboratory to start fashioning scientific instruments for the coming expedition near the binary neutron star. This event was going to require some special instruments, and Janeway didn’t want to miss any of it, Qavok ships or not.

  She was still having problems with the notion that the Qavoks seemed to think they could actually control a neutron star explosion. The scale of such control seemed beyond anything possible for the Federation, let alone a race like the Qavok. And then to use such a thing to destroy an entire homeworld system of an enemy. It was barbaric almost beyond comprehension.

  In the lab Seven of Nine was already working, bent over a panel, focused. She didn’t even bother to look up as they came in. Janeway smiled. Typical of Seven.

  As a first step in Dr. Maalot’s quick orientation, Janeway showed him various astrophysical instruments that were already being used on Voyager. The first device she showed him was an X-ray imagingspectrometer, the business end of the equipment—the X-ray detector itself—was mounted outside the ship. Within a few minutes, Maalot not only understood how the device worked, but was offering suggestions on how to enhance its time-resolution capability and dynamical range to make it more suitable for observing the rapidly varying emission from the neutron-star pair.

  After an hour of intensive work together in the laboratory, Janeway, Maalot, Seven, and Torres had laid out a viable observing strategy for the binary neutron star.

  “Let me review what we have got now,” Janeway said, brushing hair back off her forehead. “We will, by the time we arrive, have the correct instruments modified to make observations in all electromagnetic wavelengths.”

  Torres nodded.

  “All the way from gamma-ray to radio frequencies. In all instances we need to improve the time-resolution of existing detectors.”

  “Correct,” Seven said.

  “The gravitational wave detector will be a challenge,” B’Elanna said, frowning.

  “I am confident that we are up to the task,” Seven said.

  “Given the short time?” Janeway asked. She had her doubts if it could all be done, but something was better than nothing at this point.

  Seven glanced at her. “The shortness of the time will pose difficulties, but I can have the task finished.”

  “Good,” Janeway said, smiling and nodding. She knew that if Seven said something would be done, it would be done.

  “I’ll set up the observation program,” Torres said. “We should be ready to start making preliminary observations in a few hours, at most. By the time we arrive at the binary, at any rate, every detector should be tested and operating.”

  Dr. Maalot bowed slightly toward B’Elanna, looking very formal as he spoke. “Lieutenant Torres, I would be delighted to assist you in this task. I am handy in jobs of this sort, if I may say so myself.”

  Janeway managed to not laugh at his sudden formality.

  With a glance at Janeway, B’Elanna said, “Thank you, Dr. Maalot, I’ll be happy to take you up on your offer.”

  “Let Chakotay know if you need more help,” Janeway said. “He will see to it.”

  “Good,” B’Elanna said.

  “And when you are set up and ready, please report to my ready room,” Janeway said. “I’ve got something I want to talk to you about.”

  B’Elanna glanced at her, then nodded.

  “Seven, you come, too.”

  Seven didn’t bother to look up from the panel she was working on. B’Elanna again only nodded, but she clearly looked puzzled.

  “I’ll explain when you get there,” Janeway said. Then she turned and headed for the bridge, her thoughts already racing ahead to the binary neutron star, and what it might mean for them.

  * * *

  “This binary could be the break we have been looking for,” Janeway said, as much to herself as to Torres and Seven as she paced behind her desk. “We might, just might, find a way to reach Federation space faster with the use of this binary system.”

  “How so, Captain?” B’Elanna asked.

  “Over the past two hours I’ve gone back over some papers in the field of relativistic astrophysics, including several seminal papers on theoretical gravitational radiation from neutron-star binaries.”

  Both Seven and B’Elanna said nothing, so she went on. “In one of the last two papers in the series, a theoretically possible device is described for storing up the tremendous energy emitted by a close neutron-star pair in the form of gravitational waves, manifesting themselves as traumatic disturbances in the space-time continuum. The author of the paper thought it possible, but extremely
unlikely, that there would be an opportunity to actually test the device in real life.”

  “But we now have that opportunity, don’t we, Captain?” B’Elanna said, shaking her head. “I don’t think we need any more on our plate, to be honest. It’s going to be—”

  Janeway held up her hand for Torres to stop. “You don’t understand what I’m getting at.”

  “Captain,” Seven said. “I am at a loss, also. The orbital energy and the angular momentum of two objects of roughly solar masses speeding around each other at relativistic velocity radiates away as gravitational waves. Correct?”

  “Yes,” Janeway said. “In theory.”

  “Then,” Seven said, “as the orbit shrinks, the rate will pick up in inverse proportion to the fifth power of the separation between the two stars. It will be an immense quantity of energy. Am I correct?”

  “Again, it would seem so,” Janeway said, surpressing a smile.

  “So you are proposing that we are to build a device that can intercept and store some of the gravitational energy that is being emitted from the neutron star binary?”

  “To use it to help us get home,” Janeway said.

  B’Elanna frowned.

  “In order to contain the immense amount of energy,” Seven said, “within the confines of this device, we would need to distort the space-time continuum entirely out of shape inside the receptor.”

  “Theoretically, yes,” Janeway said. “I can give you technical instructions based on the paper’s theory. The original paper is stored in the ship’s computer library.”

  “To be honest, Captain,” B’Elanna said, “this sounds like a long shot.”

  By now Seven was so caught up in the hypothesis that she continued, ignoring Torres’s reservations. “With such a virtually unlimited supply of energy, we should, theoretically, with certain modifications, be able to maintain a higher warp speed consistently, cutting many years from the length of the trip ahead.”

  Janeway nodded. “As well as supply our replication energy needs for a great length of time.”

  B’Elanna still wasn’t convinced. “I don’t see how we can connect the energy into the warp drives, let alone the ship’s basic systems.”