Less than a week after Fox, NatGeo and the producers of "Cosmos" announced they were investigating three women's accounts of sexual misconduct against host Neil deGrasse Tyson, a fourth accuser has come forward.

In a Buzzfeed News story published Wednesday, an unnamed woman says the celebrity astrophysicist drunkenly propositioned her at a 2010 staff holiday party at the American Museum of Natural History in New York, where he serves as director of the Hayden Planetarium.

In 2014, she reported the incident to her employer as justification for refusing to collaborate with him on a proposed project. She later shared that email with Buzzfeed, which says it has been tracking the Tyson story for more than three years.

She joins three other accusers, whose allegations span 30 years. First came Tchiya Amet, who claims he drugged and raped her while they were grad students in the astrophysics program at the University of Texas in the 1980s. She went public with her story in 2014.

Last weekend, two more women followed: Ashley Watson, his former assistant on Cosmos, who says he made advances one night at his apartment after work, and Dr. Katelyn N. Allers, a Bucknell University professor who says she was "felt up" by Tyson at an American Astronomical Society convention in 2009.

More: Neil deGrasse Tyson denies misconduct allegations, welcomesinvestigation

Tyson, 60, offered his own recollections regarding Amet, Watson and Allers in a lengthy Facebook post on Saturday, adding that he welcomes the investigation announced by Fox and National Geographic.

"In any claim, evidence matters. Evidence always matters," he wrote. "But what happens when it’s just one person’s word against another’s, and the stories don’t agree? That’s when people tend to pass judgment on who is more credible than whom. And that’s when an impartial investigation can best serve the truth – and would have my full cooperation to do so."

USA TODAY has reached out to Tyson's representatives for comment regarding the newest allegation. However, in his blog post, he noted that he previously declined to comment on the allegations through the media, citing his belief that "serious accusations should not be adjudicated in the press."