HD 98618: A Star Closely Resembling Our Sun

Abstract

Despite the observational effort carried out in the last few decades, no perfect solar twin has been found to date. An important milestone was achieved a decade ago by Porto de Mello & da Silva, who showed that 18 Sco is almost a solar twin. In the present work, we use extremely high resolution (R = 105), high signal-to-noise ratio Keck HIRES spectra to carry out a differential analysis of 16 solar-twin candidates. We show that HD 98618 is the second-closest solar twin and that the fundamental parameters of both HD 98618 and 18 Sco are very similar (within a few percent) to the host star of our solar system, including the likelihood of hosting a terrestrial planet within their habitable zones. We suggest that these stars should be given top priority in exoplanet and SETI surveys. Show more