Could someone explain how the whole Star Pact of the warlocks is supposed to work flavor-wise?

I understand Infernal comes from obvious deal-with-the-devil type origin, and the Fey pact comes from those mischievous spirits that somehow share a relation to elves, but what is the Star Pact? Is that supposed to be some sort of elder-god type thing?

I ask because I'm trying to figure out how such flavor would work in my setting, as I do have a Star Pact Tiefling Warlock in the group. Now, I have no trouble with refluffing stuff or letting him switch his powers and background around, I'm just kind of curious.