Firmamentum.

Every chart has a center, and the center of this one is empty of data. The guitar sits at the pole - no repository, no first commit, no way to measure it with the instruments that measured everything else. That is not a gap in the record. That is what a pole is. The one fixed point is the thing that was never an experiment, so nobody thought to log it. The record begins in April 2025; the instrument began half a life earlier; the whole measured sky turns around the one thing it cannot see.

Johannes Hevelius engraved his atlas twice. Four decades of measurement burned with the observatory in 1679; he was sixty-eight; he began again that year. The atlas - Firmamentum Sobiescianum, this plate's namesake - was finished by his wife Elisabeth after his death. The lesson is the direction of dependence: the catalog is rebuilt from the practice. The practice is never rebuilt from the catalog. Lose every repository tomorrow and this sky would re-form within the year, because the sky was never the files.

Nicolas-Louis de Lacaille sailed under an unnamed southern sky and filled it with furniture - the furnace, the clock, the easel, the pump. No heroes, no gods; instruments. It was a claim about what deserves to be written on the heavens: not what a life worships but what a life does. This plate follows him - the lyre, the watchtower, the press, the bridge, the hearth. An inventory of tools is the only honest genre of self-portrait.

Johann Elert Bode drew Uranographia seventeen thousand stars deep because a sky is not its brightest stars - the field is the fact. Most of what is plotted here is dim: experiments that ran a week, ideas that got one evening. An atlas refuses to call them failures. They are field - the faint mass that makes the bright figures legible at all. Nobody has ever seen a constellation except against the lesser stars it is drawn from.

Two kinds of light cross this chart. The wanderers are the engagements - bright, moving, paying their way along the ecliptic, deliberately unnamed, and like all planets they leave and return. A practice that mistakes its planets for its stars has no sky left when they set. The fixed stars are the practices, and the innermost of them are circumpolar: from this latitude they never go below the horizon at all. Whatever drops from view was only seasonal, and seasons come back. One mark here is neither history nor visitor - a dashed circle in Cithara where a light is expected in August, drawn the way every prediction is drawn: as a place held open.