AU Microscopii has at least two spectral components: a 4000 K ambient photosphere and cool spots that have a temperature of 3000 K

Star system: AU Microscopii | Distance from the Sun: 31.7 light years

Researchers have used ground-based photometry and spectra to study the unocculted starspots on the young star AU Mic. They find that AU Mic has at least two spectral components: a 4000 K ambient photosphere and cool spots that have a temperature of 3000 K and cover 39% of the surface. They also detect a third flux component, which they attribute to flare flux. This study will help us better understand the starspot coverage on AU Mic and other stars, which is important for interpreting the transmission spectra of exoplanets transiting these stars.

Scientific study

Quantifying the Transit Light Source Effect: Measurements of Spot Temperature and Coverage on the Photosphere of AU Microscopii with High-Resolution Spectroscopy and Multi-Color Photometry (external link)