دور الأزواج النجمية الواسعة في تكوين كواكب المشتري الحارة حول الأقزام M ✛ ✦

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2607.10177

Binary stars are ubiquitous, yet it remains unclear how wide-orbit stellar companions influence the formation of hot Jupiters, particularly around M dwarfs. Here, we first report the discovery of TOI-5628Ab, a giant planet transiting a mid-type M dwarf ($$M_\ast=0.36\pm0.02\ M_\odot$$) every 4.34 days, accompanied by an associated white dwarf TOI-5628B ($$M_{\rm WD}=0.59\pm0.16\ M_\odot$$) at a projected distance of about 2,500 AU. Using TESS, ground-based photometry and SPIRou RVs, we constrain the planet radius to $$0.74\pm0.04\ R_J$$ and mass to $$0.09\pm0.04\ M_J$$, with a $$3\sigma$$ upper limit of $$0.22\ M_J$$. Building on this system, we further conduct a homogeneous systematic search for co-moving stellar companions with projected semi-major axis between 100 and 10,000 AU around all M dwarfs with confirmed giant planets with periods smaller than 10 days and radii larger than 0.7 $$R_J$$, as well as a group of field M stars with stellar properties similar to the planet sample, based on the stellar kinematics from Gaia DR3. We measure a stellar multiplicity of $$34.2\pm9.5\%$$ for M dwarfs hosting short-period giant planets, which is substantially higher than the fraction of $$5.3\pm3.7\%$$ for the field M stars by approximately a factor of 6. Our results suggest that wide-orbit stellar companions tend to promote the formation of short-period giant planets around M stars with masses $$0.21 \leq M_\ast\leq 0.64\ M_\odot$$, and high-eccentricity migration may play an important role in producing such systems.