New radial velocity observations of AH Her : Evidence for material outside the tidal radius
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Spectroscopic observations of AH Herculis during a deep quiescent state are put forward. We found the object in a rare long minima, allowing us to derive accurately the semi-amplitudes: K1 =121 ± 4 km s-1 and K2 = 152 ± 2 km s-1 and its mass functions MWsin 3i = 0.30 ± 0.01 M⊙ and MRsin 3i = 0.24 ± 0.02 M⊙, while its binary separation is given by asin i = 1.39 ± 0.02 R⊙. The orbital period Porb = 0.25812 ± 0.00032 d was found from a power spectrum analysis of the radial velocities of the secondary star. These values are consistent with those determined by Horne, Wade & Szkody. Our observations indicate that K5 is the most likely spectral type of the secondary. We discuss why we favour the assumption that the donor in AH Her is a slightly evolved star, in which case we find that the best solution for the inclination yields i = 48° ± 2°. None the less, should the donor be a ZAMS star, we obtain that the inclination is between i = 43° and i = 44°. We also present Doppler tomography of H α and H β, and found that the emission in both lines is concentrated in a large asymmetric region at low velocities, but at an opposite position to the secondary star, outside the tidal radius and therefore at an unstable position. We also analyse the H α and H β line profiles, which show a single broad peak and compare it with the previous quiescent state study that shows a double-peaked profile, providing evidence for its transient nature.
Echevarriá , J , Hernández Santisteban , J V , Segura Montero , O , Ramírez , S H , Ruelas-Mayorga , A , Sánchez , L J , Michel , R , Costero , R , González-Buitrago , D H & Olivares , J 2021 , ' New radial velocity observations of AH Her : Evidence for material outside the tidal radius ' , Monthly Notices of the Royal Astronomical Society , vol. 501 , no. 1 , pp. 596-605 . https://doi.org/10.1093/mnras/staa3615
Monthly Notices of the Royal Astronomical Society
Copyright © 2020 the Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1093/mnras/staa3615.
DescriptionThe authors acknowledge financial support prom PAPIIT project IN114917. JER acknowledges support from a ‘Leids Kerkhoven-Bosscha Fonds’ (LKBF) travel grant to visit the API at UvA. LJS and ARM would like to thank DGAPA, UNAM for financial support provided by Programa de Apoyo a Proyecto de Investigacion e Inovacion Tecnologica (PAPIIT) projects IN102517andIN102617. JVHS acknowledges support from an STFC grant ST/R000824/1.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.