When observing the Hyades star cluster in the Taurus constellation, scientists have made an intriguing discovery with a Halloween-like twist: a “zombie” is fleeing at a speed of 10 km/s.
The “zombie” in question is a white dwarf star, a “half-dead” form of stars in the cosmos. These stars are small but heavy and possess strong magnetic fields, eventually leading to a violent explosion into a supernova.
Mysterious Hyades Cluster – Image: NASA/ESA/STScI
What makes this newly discovered white dwarf star particularly fascinating is its behavior, which seems like it’s hastily escaping from the Hyades cluster at a staggering speed of 10 km/s. The Hyades star cluster is the closest open star cluster to the Solar System, located just 153 light-years away from Earth, making it convenient for observations. It comprises hundreds of stars formed at the same time, approximately 625 million years ago, from the same cloud of gas and dust.
Nevertheless, the most intriguing aspect of Hyades is its scarcity of white dwarf stars at its core. A star cluster of its size should contain numerous “zombies,” considering stars eventually die.
According to a research team led by Dr. David Miller from the University of British Columbia (Canada), the “zombie escape” they’ve discovered may be the answer.
It was identified within the vast data collected by the European Space Agency’s Gaia spacecraft, which is tasked with mapping our Milky Way galaxy.
The discovery includes not one, but three white dwarf stars that are “fleeing” from Hyades. One of them, Gaia EDR3 560883558756079616, is the largest among the three, and it’s super fast, as mentioned earlier. Despite being a dead star and having lost some mass, it still weighs 1.3 times the mass of the Sun.
“It’s fascinating to have such a massive white dwarf identified as born in the Hyades. The Hyades are not particularly rich in stars, and they are not in a particularly dense region of the galaxy,” said Dr. Miller.
The escaping stars, including the “monster” Gaia EDR3 560883558756079616, indicate that the lack of white dwarf stars in the Hyades cluster may be because other dead stars have similarly fled.
What propelled them far and fast from the Taurus cluster remains a mystery, but researchers believe that the primary reason is the loose gravitational binding of the cluster.
This enigmatic cosmic exodus might also be connected to interactions with another nearby star cluster or the movement of giant clouds of gas between clusters.
Nevertheless, regardless of the explanation, these “zombies” offer a glimpse into one possible future scenario for our own world. The Sun is expected to run out of energy in the next 5 billion years, expanding into a red giant star that will engulf three nearby planets, including Earth, before collapsing into a white dwarf.