A STAR'S LEGACY

Talu brought the new measurement onto the same screen as the previous observation record. It had been the first record he checked when he took over his shift at the Federation center monitoring distant star systems. The star, far more massive than the Sun, had been under observation for a long time. The change in its core flagged during the previous shift was still apparent in the latest measurement.

He widened the comparison interval. He did not stop at the last two records; he opened older measurements of the star as well. He followed the sequence of changes in the core and paused at the values showing the decline in fuel. After checking the latest record again, he called Aruna, the stellar physicist.

When Aruna reached the observation console, Talu pointed to two places on the screen.

“The previous shift flagged this. The change is continuing in the new measurement,” he said.

Aruna sat down and checked the order in which the records had been taken. Then he isolated the core data. He did not close the older records Talu had opened. Before saying what the latest value meant, he wanted to see how the star had reached this stage.

“Have the latest records from the other centers arrived?” he asked.

“Some have. I requested the rest,” Talu said.

“Let’s open what we have.”

Talu placed the data transmitted by the different observation centers side by side. Aruna checked the observation time of each record and compared measurements from the same period. The change identified at one center also appeared in the others. Fuel in the core had declined, and the disruption in the star’s mass balance had progressed.

Aruna put his finger on the latest measurement.

“Send these data to the science center. Include the preliminary assessment. I think it has entered its final stage,” he said.

While Talu prepared the transmission, Aruna opened the calculation interface. He updated the calculation based on the star’s previous condition with the latest data. After obtaining the result, he checked the inputs from the beginning. He was still at the same console when Talu brought up the file to be transmitted.

“Are we expecting the core to collapse?” Talu asked.

“Yes. The fuel is almost exhausted. The core is approaching the point where it can no longer support its own weight,” Aruna said.

Talu revised the sentence in the preliminary assessment. He had not used wording that said the explosion had begun; even so, he wanted a clear distinction between the star’s current condition and the expected development. He showed the file to Aruna. Aruna read and approved the text, and Talu sent the records to the Federation science centers.

They continued observing while they waited for a response. Talu added new data in the order they arrived. After completing the collapse calculation, Aruna examined the condition of the outer layers. When the core collapsed rapidly, the star’s outer layers would be hurled into space in a powerful explosion. The expected event was a supernova.

Aruna had finished his final check of the calculation when a connection request arrived from the science center. İlter, a member of the team conducting the review, appeared on the screen. He spoke while looking at the records in front of him.

“The calculations from the other observation centers have arrived too. They agree with your result,” he said.

“We sent the latest measurements as well. The change in the core is continuing,” Aruna said.

İlter opened the new file. Aruna kept the data he had used on the screen during the review. İlter asked about the observation time of one record. Talu opened the relevant information and showed him. They had to avoid confusing the sequence of measurements when comparing results from different centers.

When the review was complete, İlter looked up.

“All the calculations give the same result. The star has passed the point of no return,” he said.

Aruna finalized the assessment in front of him. Talu entered the new status in the record of the star they had been watching for so long. Further observations would be used to narrow the estimated time of the approaching collapse.

İlter opened the timing calculation Aruna had prepared.

“How much can we narrow this interval?” he asked.

“We can recalculate using the latest changes in the core. But we can’t give an exact moment,” Aruna said.

“Send the new calculation too. We’ll adjust the observation frequency accordingly.”

When the connection closed, Talu separated out the most recent measurements. As Aruna added them to his calculation, Talu marked which records had been used. That would allow the team at the science center to repeat the procedure with its own data.

Aruna did not send the first result as soon as it appeared. He examined the inputs first, then the difference from the previous calculation. Talu opened the comparison file. The new result did not change the assessment that the star would collapse soon. Only the approximate interval in which the explosion was expected had been updated.

“I’m leaving the exact collapse time section blank,” Talu said.

“Don’t leave it blank. Write that it could not be determined. Show the approximate interval separately,” Aruna said.

Talu adjusted the record accordingly. The core’s collapse, the ejection of the outer layers into space, and the powerful supernova expected afterward were included in the same assessment. Each of these stages, none of which had happened yet, was identified as part of the calculated sequence.

After sending the file to the science center, he opened the observation schedule. He reviewed the current intervals with Aruna. Observations around the star would become more frequent, and the timing calculation would be repeated as new measurements arrived.

Aruna selected the record series they would use and showed it to Talu.

“Compare every new measurement with this. Mark the changes in the core separately,” he said.

Talu completed the adjustment. He activated the new observation schedule stored in the Federation systems and reopened the star’s core data for the next measurement.