Astronomers: Planet Escaped Death in Binary System

Facts

• The planet 8 Ursae Minoris b, which was discovered in 2015, was never supposed to have been visible as it should have been engulfed by a nearby dying star. Scientists now believe they know how the planet survived.¹
• According to a study published in the journal Nature, the lifespan of 8 Ursae Minoris, the star accompanying the gas giant planet, was supposed to run out and engulf its orbital neighbor.²
• Researchers now believe that 8 Ursae Minoris b started out orbiting two stars, one of which was 8 Ursae Minoris. As the smaller of the two stars, Ursae Minoris stripped its bigger neighbor's atmosphere, leaving it as a shrunken, helium-rich version of itself but keeping the danger away from the planet.³
• The going theory is that as dwarf stars — those like Earth's Sun — deplete all the hydrogen burning at their core, they become red giants that expand and consume all the nearest terrestrial objects, as is expected to occur in our solar system in roughly one billion years.²
• While it's mere speculation, the scientists also theorized the possibility that the planet was actually formed by the debris ejected by the merging of the two stars. Lead researcher Dr. Marc Hon from the University of Hawaii said, "Most stars are in binary systems, but we don't yet fully grasp how planets may form around them."¹
• While the current understanding is that most are in binary systems, Dr. Hon said that "many more peculiar planetary systems may exist" due to companion stars like 8 Ursae Minoris.²

Sources: ¹BBC News, ²TechSpot, and ³Ars Technica.  

Narratives

• Narrative A, as provided by Universe Today. This star binary theory has been accepted for years, leading scientists to believe that our Sun once had its own companion. Researchers have also said they found an exact twin 184 light-years away, which could mean the existence of the Neptune-sized Planet Nine and possibly that may suggest the presence of another body in our celestial neighborhood. Planets are showing themselves to be cunning at evading cosmic catastrophe.
• Narrative B, as provided by EarthSky. This finding also supports another hypothesis — resilient plants in binary systems may be a good place to search for life. These systems very likely contain the building blocks of life, and astronomers may want to focus on these instead of just on solar systems that look like our own. 8 Ursae Minoris b itself may not be brimming with life, but other planets in binary systems be worth a close look for exobiologists.

Predictions