The uncertainty of science: Star refuses to erupt when predicted
Based on records of two past eruptions approximately eighty years apart, astronomers had predicted that the binary star system T Coronae Borealis would erupt sometime in September 2024, brightening from magnitude 10 to as much as magnitude 2, making it one of the sky’s brighter stars for a short while.
That eruption however has so far not taken place.
“We know it has to happen,” astrophysicist Elizabeth Hays, who is watching T CrB every day using NASA’s Fermi gamma-ray space telescope, told Space.com in a recent interview. “We just can’t pin it down to the month.”
The unpredictability stems partly from limited historical records of T CrB’s outbursts. Only two such eruptions have been definitively observed in recent history: on May 12, 1866, when a star’s outburst briefly outshined all the stars in its constellation, reaching magnitude 2.0, and again on February 9, 1946, when it peaked at magnitude 3.0. These events appear to follow the star’s roughly 80-year cycle, suggesting that the next outburst may not occur until 2026. [emphasis mine]
The eruptions are thought to occur because the system’s denser white dwarf star pulls material from the lighter orbiting red giant. Over time that material accumulates on the surface of the white dwarf until it reaches critical mass, triggering a nuclear explosion that we see as the star’s brightening.
Astronomers have assumed this process is predictable, but in truth it really is not. For example, the star has brightened at other times, in 1938 and again in 2015, though not as much. These other brightenings suggest a great deal of uncertainty in the rate in which material accumulates, as well as how much is needed to trigger a nuclear burst.
Because of the possibility however of a burst at any time, astronomers have been poised eagerly now for months, observing the star regularly with the many orbiting telescopes that can observe it not only in optical wavelengths but in gamma, X-rays, and infrared. The latter capabilities didn’t exist in previous eruptions, and are now able to tell them things about the system that was impossible for earlier astronomers.
Assuming the eruption occurs at all. Despite the certainty of the astronomer’s quote highlighted above, there is no certainty here. This star system will do whatever it wants, despite the predictions of mere human beings.
Based on records of two past eruptions approximately eighty years apart, astronomers had predicted that the binary star system T Coronae Borealis would erupt sometime in September 2024, brightening from magnitude 10 to as much as magnitude 2, making it one of the sky’s brighter stars for a short while.
That eruption however has so far not taken place.
“We know it has to happen,” astrophysicist Elizabeth Hays, who is watching T CrB every day using NASA’s Fermi gamma-ray space telescope, told Space.com in a recent interview. “We just can’t pin it down to the month.”
The unpredictability stems partly from limited historical records of T CrB’s outbursts. Only two such eruptions have been definitively observed in recent history: on May 12, 1866, when a star’s outburst briefly outshined all the stars in its constellation, reaching magnitude 2.0, and again on February 9, 1946, when it peaked at magnitude 3.0. These events appear to follow the star’s roughly 80-year cycle, suggesting that the next outburst may not occur until 2026. [emphasis mine]
The eruptions are thought to occur because the system’s denser white dwarf star pulls material from the lighter orbiting red giant. Over time that material accumulates on the surface of the white dwarf until it reaches critical mass, triggering a nuclear explosion that we see as the star’s brightening.
Astronomers have assumed this process is predictable, but in truth it really is not. For example, the star has brightened at other times, in 1938 and again in 2015, though not as much. These other brightenings suggest a great deal of uncertainty in the rate in which material accumulates, as well as how much is needed to trigger a nuclear burst.
Because of the possibility however of a burst at any time, astronomers have been poised eagerly now for months, observing the star regularly with the many orbiting telescopes that can observe it not only in optical wavelengths but in gamma, X-rays, and infrared. The latter capabilities didn’t exist in previous eruptions, and are now able to tell them things about the system that was impossible for earlier astronomers.
Assuming the eruption occurs at all. Despite the certainty of the astronomer’s quote highlighted above, there is no certainty here. This star system will do whatever it wants, despite the predictions of mere human beings.