Pressure-Broadened Sodium Absorption Produces Green Perceived Hue in Cool Polluted White Dwarf WD J1330+6435
What Was Observed (Empirical Data)
Researchers at the University of Warwick mapped archival optical spectroscopy from the Sloan Digital Sky Survey (SDSS) through human colorimetric response models for the cool (~4,300 K) DZ-class white dwarf WD J1330+6435. Heavy atmospheric pollution from accreted planetary debris—specifically high concentrations of sodium, calcium, and lithium in an ultra-dense helium-dominated atmosphere—induces extreme pressure-broadened absorption across yellow, orange, and red wavelengths, leaving a net spectral peak in the green (chartreuse) visual band.
The Reality Check (Anti-Hype Analysis)
WD J1330+6435 is not a main-sequence star undergoing novel nuclear fusion, nor does it violate thermal blackbody physics; it is a faint, cooling stellar remnant whose thermal continuum is heavily sculpted by chemical absorption lines. Furthermore, the 'green star' designation is a colorimetric reconstruction of how its spectrum maps to human photopic vision rather than a direct naked-eye observation, as the object is far too dim to trigger human color receptors without telescopic light collection.
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