In the photo caption, Lohan described the photo as an homage to Tate:

"I LOVE SHARON TATE #CANCERmeetsAQUARIUS #themelook #hippieWINTERCHIC"

It's not clear if Lohan realized it was Manson's birthday when she posted the photo.

Tate was pregnant when she was killed by Manson and cult members who broke into her Beverly Hills home and stabbed her to death.

Manson is serving nine consecutive life sentences at a California prison.