Scientists map six stellar twins to understand our Sun's place in the cosmos
Researchers have precisely characterized six stars nearly identical to our Sun using space telescopes and ground-based spectroscopy, pinning down their ages, masses, and sizes with unprecedented accuracy. The findings provide a crucial benchmark for stellar physics models and could improve predictions about long-term solar behavior—critical for climate modeling and long-range space mission planning.
Originaltitel: Characterizing six seismic solar analogs observed by Kepler, K2, and HERMES
<p>Solar analogs-stars that closely match the fundamental properties of the Sun-provide key benchmarks for testing stellar structure and evolution across different ages and activity levels. Their detailed characterization helps place the Sun into context within the broader population of solar-like stars. This study presents the characterization of six seismic solar analogs observed by the NASA Kepler and K2 missions. Combining asteroseismic constraints from space-based photometry with high-resolution spectroscopy and Gaia astrometry, we derived their fundamental parameters and assessed their resemblance to the Sun. Global seismic properties and individual oscillation modes were extracted from the photometric light curves, while atmospheric parameters were obtained from data collected by the High-Efficiency and High-Resolution Mercator Echelle Spectrograph (HERMES) at the Mercator telescope. Stellar modeling using seven independent stellar evolution codes yielded consistent masses, radii, and ages. These stars have masses between 0.91 and 1.04 M-circle dot, radii between 0.95 and 1.08 R-circle dot, and ages from about 1.8-9.1 Gyr, with typical systematic uncertainties of +/- 0.02 M-circle dot, +/- 0.01 R-circle dot, and +/- 0.7 Gyr, respectively. One star, EPIC 206064678, exhibits properties very similar to those of the Sun, with M = 1.016 +/- 0.033 M-circle dot, R = 0.990 +/- 0.011 R-circle dot, and an age of 5.40 +/- 0.12 Gyr. It can therefore be considered a close solar twin, although it is slightly older and more metal-rich (0.25 +/- 0.07 dex). Four targets display binarity signatures and all exhibit very low chromospheric activity. This work broadens the sample of well-characterized seismic solar analogs toward a larger sample of metallicities and ages, providing new references for comparative stellar studies and future asteroseismic investigations.</p>