标题： 两个短周期食双星系统的自转-公转对齐情况 显示英文标题

标题： The Spin-orbit alignment of two short period eclipsing binary systems

摘要： 我们对来自Minerva-Australis设施的TESS光度数据和径向速度测量进行了联合分析，针对两个短周期食双星TIC 48227288和TIC 339607421。 TIC 339607421拥有一颗M型矮星伴星（$M_B = 0.294 \pm 0.013 \: M_{\odot}$，$R_B = 0.291 \pm 0.006 \: R_{\odot}$）围绕一颗F6V恒星（$M_A=1.09 \pm 0.04 \: M_{\odot}$，$R_A=1.21^{+0.03}_{-0.02} \: R_{\odot}$）轨道运行。 虽然TIC 48227288包含一个晚期K类伴星（$M_B=0.635 \pm 0.037 \: M_{\odot}$，$R_B = 0.605 \pm 0.011 \: R_{\odot}$）围绕F3V恒星（$M_A = 1.36^{+0.06}_{-0.08} \: M_{\odot}$，$R_A = 1.61 \pm 0.03 \: R_{\odot}$）运行。 两个伴星都遵循短周期、近圆形轨道（$P_B = 2.4-3.0$d，$e \approx 0.001$）。 每个系统的天球投影偏斜度是通过径向速度扰动的经典分析和重新加载的Rossiter-McLaughlin（RRM）技术得出的。 经典的的方法表明两个系统都有较小的自旋-轨道不对齐（TIC 339607421 和 TIC 48227288 分别为$\lambda_A = -14.7^{+5.4}_{-5.9}$ deg 和$-17.8^{+1.9}_{-2.0}$ deg）。RRM 分析得出的倾角更小（分别为$\lambda_A = -8.2 \pm 0.2$ deg 和$-9.5 \pm 0.2$ deg），但确认了从经典分析中推断出的微小不对齐。即使不对齐程度不大，发现的不对齐且圆形的轨道也是值得注意的，并暗示当前双星形成和轨道演化的模型可能存在潜在的不足。因此，对这些及类似系统进行进一步研究似乎是合理的。 显示英文摘要

摘要： We present a joint analysis of TESS photometry and radial velocity measurements obtained from the Minerva-Australis facility for two short-period eclipsing binaries, TIC 48227288 and TIC 339607421. TIC 339607421 hosts an M-dwarf companion ($M_B = 0.294 \pm 0.013 \: M_{\odot}$, $R_B = 0.291 \pm 0.006 \: R_{\odot}$) orbiting an F6V star ($M_A=1.09 \pm 0.04 \: M_{\odot}$, $R_A=1.21^{+0.03}_{-0.02} \: R_{\odot}$). While TIC 48227288 contains a late K class companion ($M_B=0.635 \pm 0.037 \: M_{\odot}$, $R_B = 0.605 \pm 0.011 \: R_{\odot}$) orbiting an F3V star ($M_A = 1.36^{+0.06}_{-0.08} \: M_{\odot}$, $R_A = 1.61 \pm 0.03 \: R_{\odot}$). Both companions follow short period, near-circular orbits ($P_B = 2.4-3.0$ d, $e \approx 0.001$). Sky-projected obliquities for each system were derived using a classical analysis of the RV perturbation and the Reloaded Rossiter-McLaughlin (RRM) technique. The classical method indicates minor spin-orbit misalignment for both systems ($\lambda_A = -14.7^{+5.4}_{-5.9}$ deg and $-17.8^{+1.9}_{-2.0}$ deg for TIC 339607421 and TIC 48227288, respectively). The RRM analysis yields smaller obliquities ($\lambda_A = -8.2 \pm 0.2$ deg and $-9.5 \pm 0.2$ deg respectively), but confirms the minor misalignment inferred from the classical analysis. The findings of misaligned, circular orbits are notable even though the misalignments are not large, and suggest potential gaps in current models of binary formation and orbital evolution. As such, further investigation of these and similar systems appears warranted.