CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris

Through the photometric observations of the near-contact binary, XZ CMi, new BV light curves were secured and seven times of minimum light were determined. An intensive period study with all published timings, including ours, confirms that the period of XZ CMi has varied in a cyclic period variation...

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Main Authors: Chun-Hwey Kim, Jang-Ho Park, Jae Woo Lee, Jang-Hae Jeong, Jun-Young Oh
Format: Article
Language:English
Published: Korean Space Science Society (KSSS) 2009-06-01
Series:Journal of Astronomy and Space Sciences
Subjects:
Online Access:http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2009/v26n2/OJOOBS_2009_v26n2_141.pdf
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spelling doaj-dcd8338d406b4424b39011c301394d7a2020-11-25T00:26:24ZengKorean Space Science Society (KSSS)Journal of Astronomy and Space Sciences2093-55872093-14092009-06-0126214115610.5140/JASS.2009.26.2.141CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis MinorisChun-Hwey Kim0Jang-Ho Park1Jae Woo Lee2Jang-Hae Jeong3Jun-Young Oh4Dept. of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDept. of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaKorea Astronomy and Space Science Institute, Daejeon 305-348, KoreaDept. of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDept. of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaThrough the photometric observations of the near-contact binary, XZ CMi, new BV light curves were secured and seven times of minimum light were determined. An intensive period study with all published timings, including ours, confirms that the period of XZ CMi has varied in a cyclic period variation superposed on a secular period decrease over last 70 years. Assuming the cyclic change of period to occur by a light-time effect due to a third-body, the light-time orbit with a semi-amplitude of 0.0056d, a period of 29y and an eccentricity of 0.71 was calculated. The observed secular period decrease of -5.26× 10^{-11} d/P was interpreted as a result of simultaneous occurrence of both a period decrease of -8.20 × 10^{-11} d/P by angular momentum loss (AML) due to a magnetic braking stellar wind and a period increase of 2.94 × 10^{-11} d/P by a mass transfer from the less massive secondary to the primary components in the system. In this line the decreasing rate of period due to AML is about 3 times larger than the increasing one by a mass transfer in their absolute values. The latter implies a mass transfer of dot M_{s}= 3.21 × 10^{-8} M_⊙ y^{-1} from the less massive secondary to the primary. The BV light curves with the latest Wilson-Devinney binary code were analyzed for two separate models of 8200K and 7000K as the photospheric temperature of the primary component. Both models confirm that XZ CMi is truly a near-contact binary with a less massive secondary completely filling Roche lobe and a primary inside the inner Roche lobe and there is a third-light corresponding to about 15-17% of the total system light. However, the third-light source can not be the same as the third-body suggested from the period study. At the present, however, we can not determine which one between two models is better fitted to the observations because of a negligible difference of sum (O-C)^2 between them. The diversity of mass ratios, with which previous investigators were in disagreement, still remains to be one of unsolved problems in XZ CMi system. Spectroscopic observations for a radial velocity curve and high-resolution spectra as well as a high-precision photometry are needed to resolve some of remaining problems.http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2009/v26n2/OJOOBS_2009_v26n2_141.pdfeclipsing binaryXZ CMiperiod variationthird-bodyphotometric solution
collection DOAJ
language English
format Article
sources DOAJ
author Chun-Hwey Kim
Jang-Ho Park
Jae Woo Lee
Jang-Hae Jeong
Jun-Young Oh
spellingShingle Chun-Hwey Kim
Jang-Ho Park
Jae Woo Lee
Jang-Hae Jeong
Jun-Young Oh
CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
Journal of Astronomy and Space Sciences
eclipsing binary
XZ CMi
period variation
third-body
photometric solution
author_facet Chun-Hwey Kim
Jang-Ho Park
Jae Woo Lee
Jang-Hae Jeong
Jun-Young Oh
author_sort Chun-Hwey Kim
title CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
title_short CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
title_full CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
title_fullStr CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
title_full_unstemmed CCD Photometric Observations and Light Curve Synthesis of the Near-Contact Binary XZ Canis Minoris
title_sort ccd photometric observations and light curve synthesis of the near-contact binary xz canis minoris
publisher Korean Space Science Society (KSSS)
series Journal of Astronomy and Space Sciences
issn 2093-5587
2093-1409
publishDate 2009-06-01
description Through the photometric observations of the near-contact binary, XZ CMi, new BV light curves were secured and seven times of minimum light were determined. An intensive period study with all published timings, including ours, confirms that the period of XZ CMi has varied in a cyclic period variation superposed on a secular period decrease over last 70 years. Assuming the cyclic change of period to occur by a light-time effect due to a third-body, the light-time orbit with a semi-amplitude of 0.0056d, a period of 29y and an eccentricity of 0.71 was calculated. The observed secular period decrease of -5.26× 10^{-11} d/P was interpreted as a result of simultaneous occurrence of both a period decrease of -8.20 × 10^{-11} d/P by angular momentum loss (AML) due to a magnetic braking stellar wind and a period increase of 2.94 × 10^{-11} d/P by a mass transfer from the less massive secondary to the primary components in the system. In this line the decreasing rate of period due to AML is about 3 times larger than the increasing one by a mass transfer in their absolute values. The latter implies a mass transfer of dot M_{s}= 3.21 × 10^{-8} M_⊙ y^{-1} from the less massive secondary to the primary. The BV light curves with the latest Wilson-Devinney binary code were analyzed for two separate models of 8200K and 7000K as the photospheric temperature of the primary component. Both models confirm that XZ CMi is truly a near-contact binary with a less massive secondary completely filling Roche lobe and a primary inside the inner Roche lobe and there is a third-light corresponding to about 15-17% of the total system light. However, the third-light source can not be the same as the third-body suggested from the period study. At the present, however, we can not determine which one between two models is better fitted to the observations because of a negligible difference of sum (O-C)^2 between them. The diversity of mass ratios, with which previous investigators were in disagreement, still remains to be one of unsolved problems in XZ CMi system. Spectroscopic observations for a radial velocity curve and high-resolution spectra as well as a high-precision photometry are needed to resolve some of remaining problems.
topic eclipsing binary
XZ CMi
period variation
third-body
photometric solution
url http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2009/v26n2/OJOOBS_2009_v26n2_141.pdf
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