Stellar Breakthroughs: The Discovery of Deuterated Methanol and the First Green Star

Show notes Episode 206 opens with the first results from ALMA's COMPASS survey: the first detection anywhere in interstellar space of fully deuterated methanol, and methanol masers turning up around more than half of a sample of young Sun-like stars. Then the first star that would look green, Magellanic Cloud pulsars recovered from decades-old Parkes data, a supernova caught days old when the universe was 1.2 billion years old, quick hits on Hera, CRS-35 and MMX, and a both-hemispheres skywatch built around the Orionids. Heavy methanol around a newborn star ALMA's COMPASS programme (11 protostars, 100+ hours, seven A&A papers) reports the first interstellar CD3OD around IRAS 4A2 in Perseus (Belloche, MPIfR) and methanol masers in more than half of its low-mass protostars (Jeong, SNU). Deuterium fraction as a formation clock; current models can't reproduce the pattern. The first green star Warwick's Hollands et al. (RASTI) compute white dwarf colours from spectra: WD J1330+6435 comes out chartreuse thanks to accreted sodium; WD J1011+2845 may be the reddest star known. Of 151 white dwarfs within 20 pc, about 1 in 30 is oddly coloured, and the median is white. Pulsars hiding in the Parkes archive Reprocessing Murriyang's Magellanic Cloud surveys finds six pulsars, five in the LMC including a 3.8 s spinner (Sengar et al., preprint); a separate search finds PSR J0103−72, the slowest radio pulsar in the SMC (Wang & Sengar, preprint). A supernova caught days old JWST's NEXUS survey caught AT 2026abck at z = 5.017 roughly 4–10 rest-frame days after explosion — the first robust z ≳ 5 transient in an unlensed field (preprint; no spectrum yet). Quick hits Hera's BRM-1 braking burn (result pending at recording), CRS-35 docks with the last iROSAs, and MMX launches Tuesday morning Japan time. Skywatch First quarter 18 Oct, Orionids peak 21–22 Oct with the Moon down before dawn everywhere, evening Mercury for the south, Venus heading into conjunction, Saturn after dark, Mars and Jupiter closing before dawn. Sources · ALMA — Cosmic Cocktail: ALMA Reveals Exotic Methanol Around Young Stars (7 Oct 2026) — https://www.almaobservatory.org/en/press-releases/cosmic-cocktail-alma-reveals-exotic-methanol-around-young-stars/ · Belloche et al., COMPASS VII, arXiv 2610.07279 — https://arxiv.org/abs/2610.07279 · University of Warwick — true colours of white dwarf stars — https://warwick.ac.uk/news/pressreleases/astronomers-reveal-true-colours-of-white-dwarf-stars/ · Hollands et al.,