One thing that human beings who are explorers need to be reminded of often: the civilizations in a region of space see things before we get there, and tell their stories in their own ways. Humans who are thoughtful tend to listen, and also, survive to add their own part to the story.
The Amanirenas was on a transit after assisting with some infrastructure issues for a settlement before it became an issue – my uncle, Admiral Benjamin Banneker-Jackson, and also Commodore Wilhelm Allemande had come out of retirement to look back at a century of data to get ahead of problems that were slowly accruing because of old data that had been overlooked decades before. Things had been going well for months, and this was the general trend, but when things went bad …
“Captain Biles-Dixon, I apologize for waking you, but it appears that there is a gravitational anomaly in the Grtwen System.”
“A what?” I said.
Lt. Cmdr. Stacy Davis slowed down, knowing she was saying something unbelievable.
“The barycenter of the Grtwen system has shifted, Captain, by one million kilometers, and is still moving.”
I was already out of bed getting into uniform, and I met my first officer, Helmut Allemande, in the gangway, one eye still caked with sleep but his massive hand holding the wet wipe that would clear it, and, down the hall –
“I know I am now in senile dementia at age 95 because there is no way that the system I charted 30 years ago has shitfed its barycenter!”
“You keep forgetting, Commodore, that we have all these young people and modern tech. Anything is possible.”
“I would tell you to go somewhere and sit down and shut up, jungling, but you outrank me, Admiral!”
“82 and 95 years old, respectively, and only a minute behind us getting ready – most impressive,” my first officer said.
“Look, they are the reason we are how we are,” I said.
“Good point,” he said, with a slight smile.
“Helmut – hold that lift door!”
Commodore Wilhelm Allemande, 95, came somehow resplendent around the corner in his uniform along with Admiral Benjamin Banneker-Jackson, 82, whose bionic legs never grew tired while the rest of him was looking just as spry.
“I'm looking forward to seeing what is going on because the science is going to be amazing,” my admiral uncle was saying, “but my memory also tells me that unless a Jupiter mass or two were somehow missed in the survey – and I know they weren't, because you and your flotilla did the survey, Commodore – we have a major issue in surveying this segment of the galaxy.”
Every human fleet officer knew what this meant … Jupiter is the only planet in the Solar System that has a relationship with the Sun such that their common center of gravity, or barycenter, is not actually inside the sun, but enough outside of it so that the Sun wobbles as it and Jupiter orbit that center. This also means that Jupiter actually does not orbit the Sun, but that barycenter between them. The four largest planets – Jupiter, Saturn, Uranus and Neptune – have the majority of the influence on the Solar System's total center of gravity. Earth and the rest are too small … just along for the ride … but adding or subtracting a Jupiter or two would make a notable change.
But on the other hand, how does anyone or anything add a few Jupiter masses here and there to a star system? This was why the entire command staff of the Amanirenas had to get up in the middle of the night.
Lt. Cmdr. Davis exited the chair on hearing the lift door open – “Admiral, Commodore, and Captain on the bridge!” – and came with tablets for us and Cmdr. Allemande to get caught up on what had been seen before we arrived. Meanwhile, the view screen was showing us what had happened; the charted barycenter of old was some inches to the left of the new barycenter, and although it was not actually perceptible to the eye, it was certain that this was a recent development.
Of course, those inches weren't inches …
“That barycenter has moved one million kilometers,” I said. “That would take about 20 Jupiter masses in our home system, but Grtwen is a smaller red dwarf, so... .”
“It's still 13.9 Jupiter masses,” Adm. Banneker-Jackson said as he looked at the tablet.
“How? I mean, where is it?” Cdre. Allemande said.
“Where is it from?” Cmdr. Allemande said as he resumed his science station. “There's a lot of space out here!”
This was a good question. For reference, all of the planets in the Solar System beside Jupiter combined do not even account for half a Jupiter mass. With Jupiter included, all the planets are just 1.4 Jupiter masses. Cmdr. Allemande had thought, first of all, of where the planetary mass equivalent of ten Solar Systems could have come from to get into the Grtwen system when there were not ten star systems within 100 light years, and nothing in space naturally traveling anywhere near the speed of light but light.
“And I don't see 14 extra Jupiters anywhere around here,” said my uncle about 14 hours later as he was looking at the charts round about, “but just because we can't see it doesn't mean it's not there. Look at this, Commodore – from 20 light-years away, ten years before you charted this system.”
The above picture was the winner of a cultural art contest in the Jiboaw system, charted from both science and storytelling of the previous 1,000 years about a local nebula 20 light years from the Grtwen System.
“So, we know there was at least one supernova observed by the natives of this region 600 years ago, but the angle of the Jiboaw civilization is exactly opposite that of Earth – if you look, the nebula that we see is proceeding from the item in the back of the image,” Adm. Banneker-Jackson said.
“OK, so then – that's what we call the Keely Nebula,” Cdre. Allemande said. “Because the prevailing theory is that nebulae spread evenly around supernovae, it would not have occurred to us that all this could be happening exactly opposite our view.”
“Or, if the star somehow exploded asymmetrically,” Cmdr. Allemande said as he began setting up the computer to work out if what were looking at could have occurred given the known laws of physics, “a large surviving fragment could have attracted and thus cleared out a lot of the dust on its side.”
“OR, we have an even older neutron star from an even older supernova – was this a binary?” Lt. Cmdr. Davis said as she pulled up the known star charts.
“Let's ask the elders of the Jiboaw,” I said, “after we find that 13.9 Jupiter masses, that is.”
“Yes, ma'am,” every officer there said.
The thing turned out to be 13.9 Jupiter masses of a neutron star fragment, meaning that there had been a kilonova somewhere in the vicinity that had not ended up in a merger into a black hole.
“OK, the plot definitely thickens,” Lt. Cmdr. Davis said after we got the buoy in place. “It has the dimensions of a basketball, but weighs 13.9 Jupiter masses … and there could be thousands of them out here, dark, with no planetary system to affect so we can find them.”
“And no sharp-witted night commander to help other ships – but you have helped every space traveler that will come through this region of space from here on, Lieutenant Commander,” I said. “Also to you, Cdre. Allemande – we never would have known something was immediately wrong but for your careful charting of this system 30 years ago.”
“Captain, I will demur that compliment just because Lt. Cmdr Davis could have figured that out if she was the first person here – it's not like a shifting barycenter isn't going to be obvious when you plan your approach into a star's gravity,” Cdre. Allemande said.
“But it certainly helped, Commodore,” Lt. Cmdr. Davis said. “I didn't even make the approach and called an all stop. There was no chance of us hitting this thing because of your charting.”
“I love this mutual admiration society,” Adm. Banneker-Jackson said. “I love the culture of this ship, because there is plenty of credit to go around, and when we finish finding these fragments, I'm putting everyone on the night crew up for a commendation.”
“Meaning we need to get this done tonight – yes, sir,” I said.
“I have already alerted our fleet ships in the general area and all the commercial ships that they are to stay clear of the area and await further updates, per your orders, Admiral,” said Lt. Jonathan Spicer.
“Well, we know what we are looking for,” I said. “Assuming a roughly even dispersion, there are plenty of them in a 20-light-year radius.”
“I have a simulation prepared as a working map,” Cmdr. Allemande said.”Better have a look at this, Captain, Commodore, and Admiral.”
The commander's cousin did not disappoint.
“Moment mal – was?”
“That is what I thought in German before thinking it in English,” Cmdr. Allemande said, “given that this fragment is here, and there is only a neutron star of 2.3 solar masses inside the Keely Nebula.”
“I'll say it aloud, looking at the Keely Nebula today and even what it looked like 30 years ago: wait, what?” I said. “We need to find 1-2 solar masses of neutron star scattered out here?”
“That's what it looks like,” Adm. Banneker-Jackson said. “Recalibrate the long-range sensors, Commander, and send our nine fellow fleet ships the calibration when they yield what they must.”
Cmdr. Allemande followed orders, and then we stopped for a long moment as what was dark in space lit up on the sensors … and then we saw what the other nine ships were picking up as well on a combined map.
Adm. Banneker-Jackson broke the silence at last after a few moments of leaning on the console, gathering himself.
“Lt. Spicer, open a channel to all nine of our fellow fleet ships – this is Adm. Benjamin Banneker-Jackson. All ships, all stop, and all day crew members are to go back to bed and come on fresh in the morning. This is not something we can handle without proper rest, and there is no immediate danger to any of our ships. All night crews are ordered to complete their shifts and refine the data presently being collected. There will be a briefing at 0630 hours for all day command crews and lead science teams for updates, further orders, and coordination of plan of work.”
“Aye, sir,” came back from nine other ships.
“Banneker-Jackson out – day crew, go back to bed – you too, Commodore, because at our ages, we know this will not work for us. I will be up at 0530 and will see the command crew of the Amanirenas at 0615 in the briefing room.”
“Yes, sir,” Cdre. Allemande, Cmdr. Allemande, and I said.
“Lt. Cmdr. Davis, you have the comm,” I said, “and Lt. Spicer, if the elders of Jiboaw on Jiboaw 5 answer back in their morning, ask them to tell us the story of the Double Birth-Death of the Gods of the Southern Sky, and let them know we have found the grandchildren of the gods.”
At 0645, Lt. Spicer had the elders of the Jiboaw on the comm, and they told us the story.
“In the beginning, there was one light, with two heartbeats, spinning madly in their love – but there came a pain in the galaxy, and one died to shield the other, but gave birth in the dying to a shield so none may see the mourning of the second heartbeat, which wobbled and wept, and also died, but gave birth to a second child, shining, that moved away from the place where her parents died … but then saw the shield, fading, dying, and decided to go be with his sibling and not wander alone.”
The artwork, as it happened, depicted the return, 478 Earth-years earlier, complete with the tracings of the orbits of the shining young neutron star nearest the Jiboaw view had taken as the gravity of the older, darker neutron star pulled it back in. The art portrayed the reunification as near to happening – and, sure enough, the simulations that our fleet computers were running showed that yes, there had been a binary – one had gone supernova 900 years ago, one had gone 600 years ago, and both would have left a neutron star – the second one had been pushed away by the supernova of the first, but afterward had not had enough mass to not be pulled back into an unstable binary relationship with the older star – and the computer math lined up with the art, with one additional find.
“The two neutron stars glanced off each other at very high speed once before finally merging, and that's what created the fragments,” Adm. Banneker-Jackson said as he briefed the other captains. “So: a glancing kilonova, then a true kilonova.”
The elders of the Jiboaw confirmed it from their records: the glancing kilonova had occurred 394 years before we found a fragment of it in the Grtwen System, 20 light-years away.
“And, the math squares up exactly – we know where to find all of the other fragments now,” Adm. Banneker-Jackson said. “Esteemed elders of the Jiboaw Nations, we ask your permission to add the story of the Double Birth-Death of the Gods of the Southern Sky to our buoys, so that all who pass by may know all of why these fragments must be undisturbed except in the case of grave emergency.”
“It is fitting and respectful, Admiral,” the lead elder said, “although we know as well as you do that the grandchildren of the gods can defend themselves!”
“With all their gravity, yes, Elder,” the admiral said. “but it is important for humanity to understand the entire story, not only from the perspective of our science, but also what your people observed that will help us keep all space travelers out of danger. With shared knowledge, we will continue to protect each other.”
“It is fitting and respectful, Admiral.”
“We're going to need a lot more buoys,” Lt. Cmdr. Doohan my chief engineer said after the meeting.
“Well, our improvised ten-ship flotilla will deal with the ones nearest us, and Admiral Bodega will have the information to send a flotilla equipped to finish the work,” I said. “We expect a bit of extra work, working with the grandchildren of the gods of the Jiboaw southern sky – or, two neutron stars that splattered half their combined mass over a 20-light-year radius. That alone is going to keep several ships in succession busy for years – and this is not even accounting for the fact that the remaining neutron star is so large that it may accrete one speck of star dust too many at any time and collapse to a black hole.”
To Lt. Cmdr. Stacy Davis's great relief, nothing was named after her because the Jiboaw information took precedence. However, the incident did lead to her being fast-tracked to commander and then to captain in the years to come, and she is every inch the captain I knew she would be in her days on the night command for the Amanirenas. Of course, I sent her a dark chocolate cake in the shape of a basketball upon her promotion, and called it the Davis Fragment. Because there was no other such thing in the universe, Captain Davis had a good laugh about before eating it with her new command crew and thus removing even that!