Half of universe’s stars are orphans with no galaxy

The data suggests orphan stars are probably relatively small, less massive and cooler than our Sun, but typical of most stars in the universe, said Caltech experimental astrophysicist Michael Zemcov.

The night sky as seen from Earth is brimming with starlight. But these orphans would be so distant from other stars that a view from one would offer almost complete nothingness.

“The night sky on a planet around such a star would be profoundly boring and black to human eyes – no other stars, or at least very few, no Milky Way band, only distant galaxies. You might be lucky and see your parent galaxy off in the distance like we see Andromeda,” Zemcov said.

Zemcov said scientists have traced the origin of galaxies to about 13.2 billion years ago, 500 million years after the Big Bang that created the universe.

“Galaxies have been forming and interacting continuously since then, with a peak in the star formation rate about two billion years after the Big Bang,” Zemcov said. “You have enough interactions over enough time, and you end up stripping out a lot of stars.”