Revisiting the Period Change and Frequency Analysis of a Variable Star SZ Lyncis

Ronnakrit Rattanamala; Pornapa Artsang; Chanruangrit Channok; Thaweechai Chonsungnoen; Nutchanat Krinsungnoen; Pimmada Ngiabking; Phiyada Phumnok

doi:10.69650/ahstr.2024.2274

Authors

Ronnakrit Rattanamala Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand
Pornapa Artsang National Astronomical Research Institute of Thailand (Public Organization) 260 Moo 4, Donkaew, Maerim, Chiangmai, 50180 Thailand
Chanruangrit Channok Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand
Thaweechai Chonsungnoen Bachelor of Education Program in Physics, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand
Nutchanat Krinsungnoen Bachelor of Education Program in Physics, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand
Pimmada Ngiabking Bachelor of Education Program in Physics, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand
Phiyada Phumnok Bachelor of Education Program in Physics, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, 30000, Thailand

DOI:

https://doi.org/10.69650/ahstr.2024.2274

Keywords:

Variable star, Period change, SZ Lyncis

Abstract

This study aims to investigate the period change of the variable star SZ Lyncis. The observations were conducted at the Regional Observatory for the Public, Nakhon Ratchasima (ROP-NMA), operated by the National Astronomical Research Institute of Thailand (NARIT), on January 8^th-9^th and February 19^th-20^th 2024. The data was acquired using the CCD camera with a B-filter mount on the 0.7-m reflecting telescope. We report the period change of 1.37(±0.08)´10^-12 day cycle^-1. Analysis of the O-C diagram revealed the presence of a binary companion with a semi-amplitude of 0.0052(±0.0002) days, the projected semi-major axis of 0.90(±0.04) AU, the eccentricity of 0.25(±0.09), and the orbital period of 1184.1(±1.5) days and the mass function of 0.07(±0.01) M_⨀. We also identified the time-series light curve data using the Discrete Fourier transform (DFT) in the Period04 package and obtained results of four frequencies. The main frequency of 8.29630(±0.00002) cycle day^-1 corresponds to a period of 0.1205357(±0.0000003) days. These results contribute to our understanding of the pulsation properties of SZ Lyncis and its binary system.

References

Barnes, T. G., & Moffett, T. J. (1975). Photometric properties and evidence of duplicity for SZ Lyncis. Astronomical Journal, 80, 48-55. DOI: https://doi.org/10.1086/111712

Breger, M., Stich, J., Garrido, R., Martin, B., Jiang, S.-Y., Li, Z.-P., Hube, D. P., Ostermann, W., Paparo, M., & Scheck, M. (1993). Nonradial pulsation of the delta Scuti star BU CANCRI in the Praesepe cluster. Astronomy and Astrophysics, 271, 482-486.

Breger, M. & Pamyatnykh, A. A. (1998). Period changes of Delta Scuti stars and stellar evolution. Delta Scuti Star Newsletter, 12, 7. DOI: https://doi.org/10.1515/astro-1998-0205

Collins, K. A., Kielkopf, J. F., Stassun, K. G., & Hessman, F. V. (2017). AstroImageJ: Image Processing and Photometric Extraction for Ultra-precise Astronomical Light Curves. The Astronomical Journal, 153(2), 77. DOI: https://doi.org/10.3847/1538-3881/153/2/77

Deeg, H. J. (2020). A Modified Kwee–Van Woerden Method for Eclipse Minimum Timing with Reliable Error Estimates. Galaxies, 9(1), 1. DOI: https://doi.org/10.3390/galaxies9010001

Irwin, J. B. (1952). The Determination of a Light-Time Orbit. Astrophysical Journal, 116, 211. DOI: https://doi.org/10.1086/145604

Kahraman, A. F., Çoban, Ç. G., Çelik, E., Dogan, D. S., Ekinci, O., & Aliçavuş, F. (2023). Discovery of delta Scuti variables in eclipsing binary systems II. Southern TESS field search. Monthly Notices of the Royal Astronomical Society, 534, 619-630. DOI: https://doi.org/10.1093/mnras/stad1898

Kwee, K.K., & van Woerden, H. A. (1956). Method for computing accurately the epoch of minimum of an eclipsing variable. Bulletin of the Astronomical Institutes of the Netherlands, 12, 327-330.

Lenz, P., & Breger, M. (2005). Period04 User Guide. Communications in Asteroseismology, 146, 53-136. DOI: https://doi.org/10.1553/cia146s53

Li, L.-J. & Qian, S.-B. (2013). Observations and Orbital Analysis of the High-Amplitude Delta Scuti Star SZ Lyncis: The Unusual Orbital Precession. Publications of the Astronomical Society of Japan, 65, 116. DOI: https://doi.org/10.1093/pasj/65.6.116

Moffett, T. J., Barnes, T. G., Fekel, F. C., Jr., Jefferys, W. H., & Achtermann, J. M. (1988). Orbital and Photometric Properties of SZ Lyncis. Astronomical Journal, 95, 1534. DOI: https://doi.org/10.1086/114749

Ostadnezhad, S., Forozani, G., & Ghanaatian, M. (2020). New CCD photometric investigation of high amplitude δ Scuti star V2455 Cyg. Research in Astronomy and Astrophysics, 20(7), 105. DOI: https://doi.org/10.1088/1674-4527/20/7/105

van Genderen, A. M. (1967). Variations in the period and in the light-curve of SZ Lyncis. Bulletin of the Astronomical Institutes of the Netherlands, 19, 74.

Wang, S.-M., Qian, S.-B., Liao, W.-P., Zhang, J., Zhou, X., and Zhao, E.-G. (2014). Period study of the δ Scuti variable DE Lac. Bulletin of the Astronomical Society of India, 42, 19-25.