Peremennye Zvezdy

Peremennye Zvezdy (Variable Stars) 34, No. 1, 2014

Received 7 March; accepted 13 March.

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USNO-B1.0 1329-0132547, a New Double-Mode High-Amplitude Scuti Variable

A. V. Khruslov1, A.V. Kusakin2

  1. Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia; e-mail: khruslov@bk.ru

  2. Fesenkov Astrophysical Institute, Almaty, Kazakhstan; e-mail: un7gbd@gmail.com


We present our discovery of a new double-mode high-amplitude Scuti variable, HADS(B) type, USNO-B1.0 1329-0132547. We found the frequencies and . The period ratio is typical of radially pulsating HADS(B) stars.

1. Introduction

In this paper, we present our discovery of the new variable star USNO-B1.0 1329-0132547. Its coordinates in the 2MASS catalog (Skrutskie et al. 2006) are 04443778, +42 54 34 4 (J2000.0). According to our CCD observations, this star is a double-mode high-amplitude Scuti variable, HADS(B) type. The variable was discovered in the region of the double-mode variable GSC 2901-00089; our study of the latter star will be submitted to "Peremennye Zvezdy" later.

2. Observations

Our CCD observations in the Johnson bands were performed at the Tien Shan Astronomical Observatory of the V.G. Fesenkov Astrophysical Institute, at the altitude of 2750 m above the sea level, using a Zeiss 1000-mm reflector with an Apogee U9000 D9 CCD photometer. Reductions were performed using the MaxIM DL aperture photometry package. The finding chart (Fig. 1) identifies the variable star, comparison star, and check star. The comparison star was USNO-B1.0 1329-0132636, at the coordinates 04444488 +42 55 08 7 (J2000.0), and the check star, USNO-B1.0 1329-0132524, at 04443582 +42 54 19 1 (J2000.0). The magnitudes of the comparison star in the AAVSO Photometric All-Sky Survey (APASS, http://www.aavso.org/download-apass-data) catalog are and (Johnson's system) . We express our -band measurements as magnitude differences with respect to the comparison star.

Fig. 1. The finding chart of USNO-B1.0 1329-0132547.

Our observations are available online in the html version of this paper.

3. Results

We analyzed the time series using Deeming's method implemented in the WinEfk code written by V.P. Goranskij. Using our observations of USNO-B1.0 1329-0132547, we found the frequencies and (see the power spectrum in Fig. 2). The results are presented in the Table.

Table. Detected frequencies

Mode Frequency, c/d Semi-amplitude Period, d Epoch, HJD
    , mag , mag , mag    
6.1770 0.051 0.046 0.034 0.16189 2456585.582
8.0561 0.053 0.049 0.040 0.12413 2456585.598

Fig. 2. The power spectra of USNO-B1.0 1329-0132547 for the frequencies and , band.

The light curves of USNO-B1.0 1329-0132547 in the , and bands are displayed in Figs. 3, 4, 5. The power spectra of USNO-B1.0 1329-0132547 (Fig. 2) are plotted both for the raw data and with the fundamental-mode oscillations subtracted.

The -band range of USNO-B1.0 1329-0132547 is from 1728 to 1758; the -band range is 183-187. The delta magnitude -band range is 2.18-2.40. The period ratio is typical of high-amplitude double-mode Scuti stars radially pulsating in the fundamental and first overtone modes (Petersen & Christensen-Dalsgaard 1996). The infrared color index (2MASS) does not contradict the suggested type if we take into account possible reddening for the galactic latitude .


Acknowledgments: The authors are grateful to Dr. V.P. Goranskij for providing software for the light-curve analysis. We wish to thank M.A. Krugov for technical assistance during the observations. This study was supported by the Russian Foundation for Basic Research (grant 13-02-00664), the Programme "Non-stationary Phenomena of Objects in the Universe" of the Presidium of Russian Academy of Sciences, and the program "Studies of Physical Phenomena in Star-forming Regions and Nuclear Zones of Active Galaxies" of the Ministry of Education of Science (Republic of Kazakhstan).

Fig. 3. The light curves of USNO-B1.0 1329-0132547, band. Upper panels: raw data; lower panels: the folded light curves with the other oscillation pre-whitened.

Fig. 4. The light curves of USNO-B1.0 1329-0132547, band.

Fig. 5. The light curves of USNO-B1.0 1329-0132547, band.

References:

Skrutskie, M.F., Cutri, R.M., Stiening, R., et al., 2006, Astron. J., 131, 1163

Petersen, J.O., Christensen-Dalsgaard, J., 1996, Astron. and Astrophys., 312, 463





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