We report the detection of several absorption lines of neutral phosphorus ( P , Z = 15 ) in archival near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope .
We derive phosphorus abundances or interesting upper limits in 14 late-type stars with metallicities spanning - 3.8 < [ Fe/H ] < - 0.1 .
Previously , phosphorus had only been studied in Galactic stars with - 1.0 < [ Fe/H ] < + 0.3 .
Iron lines reveal abundance offsets between the optical and ultraviolet regions , and we discuss and apply a correction factor to account for this offset .
In stars with [ Fe/H ] > - 1.0 , the [ P/Fe ] ratio decreases toward the solar value with increasing metallicity , in agreement with previous observational studies .
In stars with [ Fe/H ] < - 1.0 , \langle [ P/Fe ] \rangle = + 0.04 \pm 0.10 , which overlaps with the [ P/Fe ] ratios found in several high-redshift damped Lyman- \alpha systems .
This behavior hints at a primary origin in massive stars .