Time‐Resolved Spectroscopy and Photometry of CT Serpentis and V825 Herculis

• Published in: Publications of the Astronomical Society of the Pacific Vol. 117; no. 837; pp. 1223 - 1229
• Main Authors: Ringwald, F. A., Chase, Daniel W., Reynolds, David S.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.11.2005; University of Chicago Press
• Subjects: Astronomical photometry; Astronomy; Companion stars; Earth, ocean, space; Emission spectra; Exact sciences and technology; Hemic system; Light curves; Novae; Optical bursts; Radial velocity; Spectroscopy; Stellar spectra; Spectroscopy; Photometry
• ISSN: 0004-6280; 1538-3873
• DOI: 10.1086/491721

Time‐resolved spectroscopy and photometry of two cataclysmic variables (CVs) are presented. A radial velocity study shows CT Ser (Nova Ser 1948) has an orbital period of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $0.195\pm 0.002$ \end{document} days. Its light curve shows only erratic flickering. A radial velocity study shows that V825 Her (PG 1717+413) has an orbital period of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $0.206\pm 0.002$ \end{document} days. This CV’s spectrum is similar to that of a dwarf nova in outburst, or an old nova: the long‐term light curve shows only small, “stunted” outbursts, so it is likely to be a luminous nova‐like CV, similar to a dwarf nova stuck in outburst all the time. We use time‐resolved photometry to discover quasi‐periodic oscillations (QPOs), with periods between 15 and 24 minutes, not unlike those seen in other luminous CVs.