2022AJ....163..158W

We present 12 new transit light curves and 16 new out-of-transit radial-velocity measurements for the XO-3 system. By modeling our newly collected measurements together with archival photometric and Doppler velocimetric data, we confirmed the unusual configuration of the XO-3 system, which contains a massive planet ({M}_{¶}={11.92}{-0.63}^{+0.59}  {M}_{J}) on a relatively eccentric (e={0.2853}_{-0.0026}^{+0.0027}) and short-period (3.19152 ± 0.00145 day) orbit around a massive star ({M}_{* }={1.219}_{–0.095}{+0.090}{M}_☉). Furthermore, we find no strong evidence for a temporal change of either Vsini_{* } (and by extension, the stellar spin vector of XO-3), or the transit profile (and thus orbital angular momentum vector of XO-3b). We conclude that the discrepancy in previous Rossiter-McLaughlin measurements (70.0° ± 15.0°; Hebrard et al. 2008; 37.3° ± 3.7°; Winn et al. 2009; 37.3° ± 3.0°; Hirano et al. 2011) may have stemmed from systematic noise sources.