Journal of Physical Studies 26(3), Article 3901 [9 pages] (2022)
DOI: https://doi.org/10.30970/jps.26.3901

AN X-RAY AND OPTICAL STUDY OF THE UGSU-TYPE DWARF NOVA Gaia18awg

Oleksii Sokoliuk{1,2} , Alexander Baransky{2} , Andrew Khorolskiy2, Volodymyr Vasylenko{2,3}

1Main Astronomical Observatory of the NAS of Ukraine (MAO NASU), Kyiv, UA–03143, Ukraine,
2Astronomical Observatory, Taras Shevchenko National University of Kyiv,
3, Observatorna St., 04053 Kyiv, Ukraine,
3Astronomy and Space Physics Department, Taras Shevchenko National University of Kyiv,
60, Volodymyrska St., Kyiv, UA–01033, Ukraine,
e-mail: oleksii.sokoliuk@mao.kiev.ua

Received 09 July 2021; in final form 28 June 2022; accepted 28 June 2022; published online 26 September 2022

In this work we present optical, X-ray, and UV photometry, and X-ray spectroscopy of dwarf nova Gaia18awg (ASASSN-16le). We report an analysis of photometry, spectroscopy, and measurements of physical, orbital characteristics. Gaia18awg is a U Gem + SU UMa dwarf nova system. That system, showing non-periodic outbursts and superoutbursts, superhumps during superoutbursts. From the Lisnyky (MPC 585) data we determined the superhump period. This system shows positive superhumps with period 1.56 hr, respectively, and we identify an orbital the period of 1.51 hr. We determined the hitherto unknown mass of the secondary component, radii, and orbital characteristics. Analysis of the X-ray spectra showed strong Fe $Kα$ lines at 6.7-6.8 keV, Fe $L$ complex around 1.1 keV, Ne $Kα$, Mg $Kα$, Si $Kβ$ lines with energies 0.9 keV, 1.3 keV, 1.83 keV, respectively. EPIC-pn, RGS photometry shows dominant soft X-rays during quiescence. We interpreted this as the radiation of the boundary layer.

Key words: astronomy, close binary, cataclysmic variable, X-rays.

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