Overview
- A Nature Astronomy study reports PicII-503, an extremely metal-poor, carbon‑enhanced star in the ultra‑faint dwarf galaxy Pictor II.
- Spectra show record‑low iron and calcium outside the Milky Way—about 1/43,000 of the Sun’s iron and 1/160,000 of its calcium—with exceptionally high carbon ratios.
- Researchers interpret the chemical pattern as gas enriched by a single low‑energy primordial supernova, where heavy elements fell back onto the remnant while lighter elements escaped.
- The star is estimated to be more than 10–12 billion years old and its signature links relic dwarf systems to the low‑metallicity stars seen in the Milky Way’s halo.
- The discovery used the DOE Dark Energy Camera on the NSF’s Blanco 4‑meter telescope, and coverage notes differing reports on Pictor II’s distance and host galaxy; PicII-503 sits in the dwarf’s outskirts, guiding future searches with Rubin’s LSST.