The North Atlantic right whale found dead off the coast of Barnstable was about a year old, weighed 15,000 pounds, and was just shy of 27 feet long, researchers said.

The cause of the whale’s death remained unknown, but officials were hopeful that a necropsy underway on Friday would provide crucial information that may help the endangered species.

There were no signs of external injuries, which would have indicated it was hit by a ship, authorities said.

The body of the female whale was pulled from the water Thursday.

Researchers have determined that the female is a yearling, not a calf as previously thought, according to Tony LaCasse, a spokesman for the New England Aquarium.

The weight of the whale makes it “a little small, but not significantly so,’’ said Melanie Mahoney, communication officer for animal rescue at the International Fund for Animal Welfare, one of the groups assisting with the necropsy.

Knowing the whale is a yearling is important, as only three right whale calfs have been identified during this calving season, a period that lasts from December to February, LaCasse said.

The population of right whales remains just over 500, making them “the most endangered large whale species in the Atlantic . . . and probably one of the two or three most endangered whales in the world,’’ LaCasse told the Globe Thursday.

This calf was likely born in the winter of 2015-16 and was “most likely on its own,’’ ­LaCasse said.

This death comes after about 160 of the whales, more than 25 percent of their population, were seen congregating off Cape Cod Wednesday, according to Charles “Stormy’’ Mayo, director of right whale habitat studies at the Center for Coastal Studies in Provincetown.

It remains a crime to be within 500 yards of a right whale, and their continued presence led officials from the National Oceanic and Atmospheric Administration to put voluntary speed restrictions on any boat within 12 nautical miles of Boston.

Andrew Grant can be reached at andrew.grant@globe.com.