Stellar rotation is a fundamental observable that drives different aspects of stellar and planetary evolution. In this work, we present an unprecedented manifold analysis of 160 B-type stars with light curves collected by the TESS space mission using three different procedures (fast Fourier transform, Lomb–Scargle, and wavelet techniques), accompanied by rigorous visual inspection in the search for rotation periodicities. This effort provides rotational periodicities for 6 new TESS B-type stars and confirmed periodicities for 22 targets with rotation periods previously listed in the literature. For the other 61 stars, already classified as possible rotational variables, we identify noisy, pulsational, binarity, or ambiguous variability behavior rather than rotation signatures. The total sample of 28 potential rotators shows an overlap of different classes of rotational variables, composed of α 2 Canum Venaticorum, rotating ellipsoidal, and SX Arietis stars. The combination of the three techniques applied in our analysis offers a solid path to overcome the challenges in the discrimination of rotation from other variabilities in stellar light curves, such as pulsation, binarity, or other effects that have no physical meaning. Finally, the rotational periodicities reported in the present study may represent important constraints for improving stellar evolution models with rotation, as well as asteroseismic studies of hot stars.

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SummaryIn thTs work we report the monitorTng of the synthesis of cis and tran~dTchlorobTs(ethylenedia mine)ruthenium chloride isomers by HPLC. The preparation of the cis and trans complexes were as descrTbed in the literaturewTth modifications arisTng from reversed-phase HPLC results. The cis and trans complexes were separated wth retention tTmes of 3.0 mTn and 5.5 mTn respectively usTng an ODS column (250 mmx 4.6 mm i.d., 5 tim partTcles, Alhech)and methanol/water 45/55 ratTo as mobile phase. According to HPLC results the reaction time to completion is 48 h and not 72 h as previously described. The shorter time resulted in better yield 82% and reduced by-products.

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