New Spectroscopy of U Gem
Abstract
We present new optical spectroscopic observations of U Geminorum obtained during a quiescent stage. We performed a radial velocity analysis of three Balmer emission lines yielding inconsistent results. Assuming that the radial velocity semi amplitude accurately reflects the motion of the white dwarf, we arrive at masses for the primary which are in the range of M_wd= 1.21 - 1.37 M_Sun. Based on the internal radial velocity inconsistencies and results produced from the Doppler tomography -- wherein we do not detect emission from the hot spot, but rather an intense asymmetric emission overlaying the disc, reminiscent of spiral arms -- we discuss the possibility that the overestimation of the masses may be due to variations of gas opacities and a partial truncation of the disc.
Keywords
Cite
@article{arxiv.2303.05625,
title = {New Spectroscopy of U Gem},
author = {J. Echevarría and S. H. Ramírez and M. Fuentes and L. J. Sánchez and V. Patiño and V. Chavushyan},
journal= {arXiv preprint arXiv:2303.05625},
year = {2023}
}
Comments
16 pages, 10 figures, 3 tables, to be published on RevMexAA. arXiv admin note: text overlap with arXiv:2112.03433