According to Tommaseo, one of the meanings of "pianeta" is:
- [Val.] Per Augurio, Acquisto, Influsso. Pucc. Centil. 77. 40. Il Conte Ettore non diè nella rete, Perocchè alla Montagna sanza motti Per gente er'ito con miglior pianete.
The quote is from Antonio Pucci, the XIV century. I fail to comprehend this meaning. It seems similar to 'presentiment' to me. However, this is only true for the meaning "augurio", and both "influsso" and "acquisto" do not seem to match here.
Any hints would be highly appreciated.