You’ve probably heard of a blue moon – a second full moon in a calendar month – but have you ever heard of a blue star? During wartime, they signify having a family member in the service, but in astronomy they’re extremely rare giant hot stars that are extremely short-lived. That makes a new discovery extremely exciting – astronomers mapping the Milky Way were surprised to find a new region of the Milky Way filled with giant blue stars. Get ‘em while they’re hot – or at least, get a good look at ‘em – because they’re about to explode. Considering that they’re in the Orion Arm along with our own solar system, this may not be a good thing. Is it?
“(This new region is a ) bridge of massive blue stars that spans a branch of 10,000 light years in length and leaves the spiral arm of Orion to connect with that of Perseus. In the galactic map that we have drawn, which is the update of the ALS catalog (of Alma Luminous Stars) and has 20,000 classified celestial objects, an over-density of stars is observed in a space that was previously apparently empty."
In a study published in the journal Monthly Notices of the Royal Astronomical Society, co-author Michelangelo Pantaleoni González, a researcher at the Spanish Astrobiology Center (CAB), explains how he and other astronomers used data from the ESA’s Gaia telescope to update old maps of the stars with new technology that made visible previously unknown stars. This newly discovered spur sprouting from Orion to Perseus was named the Cepheus Spur in honor of Cepheus, the king of Ethiopia in Greek mythology and the father of Andrómada. Pantaleoni González explains in Live Science that rare blue stars are responsible for the creation of many of the heavy elements (iron, copper, tin, silver, gold, platinum and others), so their eventual explosions were a good thing for Earth and their existence indicates the Cepheus Spur was an one of the most active and "alive" regions of the galaxy.
"Some of them barely live a couple of million years, five thousand times less than the Sun will live."
Unfortunately, as Pantaleoni González tells National Geographic, these are ‘live fast, die young’ stars. Of the estimated 400 billion stars in the Milky Way, less than one in a million is a blue star. However, their short lives make ours better and longer.
"The new spur shows how the production of new elements is maintained and how matter is recycled in the universe. Ultimately it is directly related to the formation of planets in other stars and to the chemical basis of life.”
And no, we’re not in any danger because the explosions already happened and we’re greatly using their gifts of heavy metals. The other gift is the new stellar maps, which will give Pantaleoni González, his colleagues and future astronomers plenty to do as they try to understand blue stars, our galaxy and the universe.
"Possibly they are oscillations of the galactic disk resulting from the convulsive evolution of the galaxy, perhaps they are the echoes of collisions with other galaxies billions of years ago or perhaps it is something else."
“Something else” from the Cepheus Spur. That’s the holy grail that ‘spurs’ all science and astronomy ... and they only happen once in a blue star.