Galaxy found that has no dark matter

WASHINGTON: Astronomers have detected for the first time a galaxy that is devoid of dark matter – material that does not emit light or energy and had been considered a fundamental part of all galaxies, including our own Milky Way.

The discovery is forcing scientists to rethink their ideas about the formation of galaxies.

“We didn’t expect that this could happen,” said Yale University astronomer Pieter van Dokkum, lead author of the research published in the journal Nature this week.

Paradoxically, the discovery of a galaxy without dark matter may confirm that the stuff actually exists by contradicting hypotheses advanced by dark-matter doubters.

Van Dokkum said the galaxy, called NGC1052-DF2 and found about 65 million light years away from Earth, also appeared to be devoid of gas and was relatively sparsely populated by stars. It is about the same size as the Milky Way, but has about 250 times fewer stars.

Dark matter is thought to comprise about a quarter of the universe’s combined mass and energy and about 80% of its total mass, but has not been directly observed. Scientists believe it exists based on gravitational effects it seems to exert on galaxies.

“We really thought that galaxies are built from, initially, a bunch of dark matter and that all the stars and all the planets and everything else is just a little frost on top,” Van Dokkum said.

The scientists spotted NGC1052- DF2 using the Dragonfly Telephoto Array, a telescope in New Mexico. They do not know how it formed, but there is a possibility a cataclysm within NGC1052- DF2 swept away all its gas and dark matter.

Van Dokkum said NGC1052-DF2 was so sparse “it is literally a see-through galaxy”. – Reuters/African News Agency (ANA)