Tähti is also Estonian. [noted -ed] The name day for Tähti in Estonia is October 19. Tähti is also sometimes used as a masculine name in Finnish and Estonian. However, it's more common for females. So, I think that the "Usage" of this name should be changed from "Finnish" to "Finnish, Estonian", and the "Gender" of this name should be changed from "Feminine" to "Feminine & Masculine". A Finnish surname derived from the Finnish and Estonian word Tähti meaning "star" exists, this surname is Tähtinen (see Tähtinen on Behind The Name Surnames Site for more info).Source: https://forebears.io/x/forenames/tähti
This is a corny, tacky, and infantile name for a person, even worse than Star is in English. I don't know any kids with this name, but it will sound very strange on a grown-up!
Source: https://forebears.io/x/forenames/tähti