Something massive seems to live in the centre of the Bloodstain - stars close to it are moving really fast. One such star (BZ2) is observed to be moving in an edge-on circle around the central mass. From the Doppler effect, its speed is measured to be 89000 km/s. And when passing in front of the central mass, it has an apparent side-ways speed of 3 arcsec per (Earth) year.
It is not possible to measure the distance to the Bloodstain using parallax - Zing's orbit is too small and the Bloodstain too far away. But perhaps we can use these motions around the central mass to calculate a distance?
Use these numbers to calculate the distance from Zing to the centre of the bloodstain (in parsecs):
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