The term <i>authoritative</i> is vague. Google doesn’t tell us exactly what it sees as authoritative. The frequency of your posts is important. Frequent posting shows Google, and other search engines, you know what you are writing about and you mean what you say.
If you post more often than your competitors you will have the edge. If they post monthly, you post two or three times a month. If they post weekly, you post two or three times a week. If they post daily, you post two or three times a day.