Tyree was a planet located in a binary star system where the Orb of the Emissary was hidden. The planet featured a desert and was enveloped by an ionized atmosphere that interfered with ship sensors.
In 2375, Benjamin Sisko traveled to Tyree with his father Joseph Sisko, his son Jake Sisko, and Ezri Dax to find the orb, after receiving a series of visions from the Prophets of Bajor.
After unearthing the orb, Sisko opened its casing and released another Prophet, one who, decades earlier, had inhabited Sarah Sisko, in order to guide her to marry Joseph Sisko and, in turn, give birth to Benjamin Sisko. This Prophet had been lying in wait within the Orb of the Emissary until released by the Emissary of the Prophets so that it could return to the Bajoran wormhole and destroy the Pah-wraith that had entered it. (DS9: "Image in the Sand", "Shadows and Symbols")
Tyree seems likely to be proximate to Earth and more familiar among Federation citizens, since Captain Sisko casually mentions the planet, obviously expecting Jake and his father to know it.