A direct black-hole mass measurement in a little red dot at high redshift (nature.com)

• Direct dynamical BH mass measurement in an LRD at z=7.04
• Mass ~50 million solar masses, consistent with virial estimates
• Keplerian rotation curve; nuclear star cluster ruled out
• BH-to-stellar mass ratio >2, indicating a 'naked' BH
• Supports heavy seed formation (direct collapse or primordial)

"Astronomers using JWST have directly measured the mass of a black hole in a strongly lensed galaxy at redshift 7.04, known as a little red dot (LRD). The black hole has a mass of about 50 million solar masses, consistent with virial estimates but ruling out alternative explanations like nuclear star clusters. The rotation curve is Keplerian, indicating a point mass. The black-hole-to-stellar-mass ratio exceeds 2, suggesting the black hole formed before its host galaxy. This supports heavy seed models such as direct collapse or primordial black holes."