While observing the Hyades star cluster in the Taurus constellation, scientists discovered a phenomenon reminiscent of Halloween: A “zombie” racing away at a speed of 10 km/s.
This “zombie” is a white dwarf star, a “half-dead” form of various stars in the universe. They are small but have high mass and strong magnetic fields, and one day, they will explosively transform into a supernova.
The newly discovered white dwarf is particularly intriguing due to its behavior of seemingly fleeing rapidly from the Hyades cluster at a terrifying speed of 10 km/s.
The Mysterious Hyades Cluster – (Image: NASA/ESA/STScI).
The Hyades cluster is the closest open star cluster to the Solar System, located only 153 light-years away from Earth, making it convenient for observations. This cluster contains hundreds of stars that formed around the same time—approximately 625 million years ago—from the same cloud of gas and dust.
However, what makes the Hyades particularly noteworthy is that it contains only a few white dwarfs at its core. A star cluster would typically contain many “zombies” because stars must eventually die.
According to a research team led by Dr. David Miller from the University of British Columbia (Canada), the “fleeing zombie” they discovered could be the answer.
This star was identified among the vast dataset from the European Space Agency’s Gaia spacecraft, a satellite tasked with mapping our Milky Way galaxy.
Not just one, but as many as three white dwarfs “running away” from the Hyades have been detected, including the aforementioned ultra-fast star, designated Gaia EDR3 560883558756079616, which is also the largest of the three.
Although it is a dead star and has lost some mass, having shrunk down, it still weighs 1.3 times that of the Sun.
“It is fascinating that such a massive white dwarf is identified as having originated in the Hyades. The Hyades is neither particularly rich in stars nor located in a particularly dense region of the galaxy,” Dr. Miller stated.
The fleeing stars, including the “monster” Gaia EDR3 560883558756079616, suggest that the Hyades cluster’s scarcity of white dwarf stars may be due to other dead stars having also fled similarly.
What propels them so far and so fast away from the Hyades cluster in Taurus remains a mystery, but researchers believe that the main cause is that this star cluster is very loosely bound.
This mysterious propulsion may also be related to interactions with a nearby star cluster or associated with massive gas clouds moving between clusters.
Regardless, “zombies” present a glimpse into one of the potential future scenarios for our own world. The Sun is expected to run out of energy in 5 billion years, erupting into a red giant that will “swallow” three nearby planets, including Earth, before collapsing into a white dwarf.
