Astronomers have found a stream of stars circling the Milky Way, like an elongated clump of cars moving together on circular racetrack. Many such streams have been found before, but this one is different: The stars in it are very old. Very. So old — 11.2 billion years — that they may have been the sole survivors from a lost generation of star clusters that once orbited our galaxy, but have long since been torn apart by it.
Ironically, the name of this structure is the Phoenix star stream. Not because it rose from the ashes of that long-ago population, but because it's in the constellation of the Phoenix. Still: fitting.
The rise of huge surveys of stars, where millions or even over a billion stars are catalogued and measured, has shown us that the galaxy is littered with long streams of stars all traveling on similar orbits. We think that these are the remnants of old star clusters or even satellite galaxies from long ago. As they orbited the Milky Way, our much larger galaxy's gravity teased them apart, pulling them like taffy into long thin streams of stars.
The Phoenix stream was discovered in the Dark Energy Survey, ...