<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0185-1101</journal-id>
<journal-title><![CDATA[Revista mexicana de astronomía y astrofísica]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. astron. astrofis]]></abbrev-journal-title>
<issn>0185-1101</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Instituto de Astronomía]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0185-11012017000100029</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Light curve and orbital period analysis of VX LAC]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Y&#305;lmaz]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Nelson]]></surname>
<given-names><![CDATA[R. H.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[&#350;enavc&#305;]]></surname>
<given-names><![CDATA[H. V.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[&#304;zci]]></surname>
<given-names><![CDATA[D. D.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Özavc&#305;]]></surname>
<given-names><![CDATA[&#304;.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gümü&#351;]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Ankara University Dept. of Astronomy and Space Sciences ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Turkey</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Prince George  ]]></institution>
<addr-line><![CDATA[Prince George ]]></addr-line>
<country>Canada</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,National Research Council of Canada Herzberg Institute of Astrophysics ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Canada</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2017</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2017</year>
</pub-date>
<volume>53</volume>
<numero>1</numero>
<fpage>29</fpage>
<lpage>36</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0185-11012017000100029&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0185-11012017000100029&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0185-11012017000100029&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract In this study, we performed simultaneously light curve and radial velocity, and also period analyses of the eclipsing binary system VX Lac. Four color (BV RI) light curves of the system were analysed using the W-D code. The results imply that VX Lac is a classic Algol-type binary with a mass ratio of q = 0.27, of which the less massive secondary component fills its Roche lobe. The orbital period behaviour of the system was analysed by assuming the light time effect (LITE) from a third body. The O &#8722; C analysis yielded a mass transfer rate of dM/dt = 1.86 × 10&#8722;8 M&#8857;yr&#8722;1 and the minimal mass of the third body to be M3 = 0.31M&#8857;. The residuals from mass transfer and the third body were also analysed because another cyclic variation is seen in O &#8722; C diagram. This periodic variation was examined under the hypotheses of stellar magnetic activity and fourth body.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Realizamos estudios simultáneos de la curva de luz y la velocidad radial de la binaria eclipsante VX Lac, y examinamos su período. Con el código W-D analizamos las curvas de luz del sistema en cuatro colores (BVRI). Los resultados indican que VX Lac es una binaria clásica tipo Algol, con un cociente de masas q = 0.27, en la cual la componente menos masiva llena el lóbulo de Roche. El comportamiento del período orbital se analizó asumiendo el efecto LITE de un tercer cuerpo. El estudio O &#8722; C dió como resultado una tasa de transferencia de masa dM/dt = 1.86 × 10&#8722;8 M&#8857; por año, y una masa mínima para el tercer cuerpo de M3 = 0.31M&#8857;. Los residuos obtenidos con transferencia de masa y con un tercer cuerpo también se analizaron, pues se observó una variación cíclica en el diagrama O &#8722; C. Se examinó esta variación con las hipótesis de actividad estelar magnética, o bien un cuarto cuerpo.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[binaries: eclipsing - stars: fundamental parameters - stars: individual (VX Lac)]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Applegate]]></surname>
<given-names><![CDATA[J. H.]]></given-names>
</name>
</person-group>
<source><![CDATA[ApJ]]></source>
<year>1992</year>
<volume>385</volume>
<page-range>621</page-range></nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bate]]></surname>
<given-names><![CDATA[M. R.]]></given-names>
</name>
</person-group>
<source><![CDATA[RMxAC]]></source>
<year>2004</year>
<volume>21</volume>
<page-range>175</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bodenheimer]]></surname>
<given-names><![CDATA[P. H.]]></given-names>
</name>
</person-group>
<source><![CDATA[Principles of Star Formation]]></source>
<year>2011</year>
<publisher-name><![CDATA[Springer-Verlag]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cannon]]></surname>
<given-names><![CDATA[A. J.]]></given-names>
</name>
</person-group>
<source><![CDATA[BHarO]]></source>
<year>1934</year>
<volume>897</volume>
<numero>12</numero>
<issue>12</issue>
</nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Demircan]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
<name>
<surname><![CDATA[Kahraman]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
</person-group>
<source><![CDATA[Ap&amp;SS]]></source>
<year>1991</year>
<volume>181</volume>
<page-range>313</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flower]]></surname>
<given-names><![CDATA[P. J.]]></given-names>
</name>
</person-group>
<source><![CDATA[ApJ]]></source>
<year>1996</year>
<volume>469</volume>
<numero>355</numero>
<issue>355</issue>
</nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Girardi]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Bressan]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Bertelli]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<name>
<surname><![CDATA[Chiosi]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
</person-group>
<source><![CDATA[A&amp;AS]]></source>
<year>2000</year>
<volume>141</volume>
<page-range>371</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Goodwin]]></surname>
<given-names><![CDATA[S. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Kroupa]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[A&amp;A]]></source>
<year>2005</year>
<volume>439</volume>
<page-range>565</page-range></nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gray]]></surname>
<given-names><![CDATA[R. O.]]></given-names>
</name>
<name>
<surname><![CDATA[Corbally]]></surname>
<given-names><![CDATA[C. J.]]></given-names>
</name>
</person-group>
<source><![CDATA[AJ]]></source>
<year>1994</year>
<volume>107</volume>
<page-range>742</page-range></nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Irwin]]></surname>
<given-names><![CDATA[J. B.]]></given-names>
</name>
</person-group>
<source><![CDATA[AJ]]></source>
<year>1959</year>
<volume>64</volume>
<page-range>149</page-range></nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kreiner]]></surname>
<given-names><![CDATA[J. M.]]></given-names>
</name>
</person-group>
<source><![CDATA[AcA]]></source>
<year>1971</year>
<volume>21</volume>
<numero>365</numero>
<issue>365</issue>
</nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Larson]]></surname>
<given-names><![CDATA[R. B.]]></given-names>
</name>
<name>
<surname><![CDATA[Zinnecker]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Mathieu]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<source><![CDATA[IAU Symposium, Vol. 200, The Formation of Binary Stars]]></source>
<year></year>
<page-range>93</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lucy]]></surname>
<given-names><![CDATA[L. B.]]></given-names>
</name>
</person-group>
<source><![CDATA[ZA]]></source>
<year>1967</year>
<volume>65</volume>
<page-range>89</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Nelson]]></surname>
<given-names><![CDATA[R. H.]]></given-names>
</name>
</person-group>
<source><![CDATA[Software by Bob Nelson]]></source>
<year>2010</year>
</nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Nelson]]></surname>
<given-names><![CDATA[R. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Terrell]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Gross]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[IBVS]]></source>
<year>2006</year>
<volume>5715</volume>
</nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Paschke]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Brat]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
</person-group>
<source><![CDATA[OEJV]]></source>
<year>2006</year>
<volume>23</volume>
<page-range>13</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rucinski]]></surname>
<given-names><![CDATA[S. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Maeder]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Eenens]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[IAU 215, Stellar Rotation]]></source>
<year>2004</year>
<page-range>17</page-range><publisher-loc><![CDATA[San Francisco, CA ]]></publisher-loc>
<publisher-name><![CDATA[ASP]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Schlegel]]></surname>
<given-names><![CDATA[D. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Finkbeiner]]></surname>
<given-names><![CDATA[D. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Davis]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<source><![CDATA[ApJ]]></source>
<year>1998</year>
<volume>500</volume>
<page-range>525</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Surkova]]></surname>
<given-names><![CDATA[L. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Svechnikov]]></surname>
<given-names><![CDATA[M. A.]]></given-names>
</name>
</person-group>
<source><![CDATA[yCat]]></source>
<year>2004</year>
<volume>5115</volume>
</nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Svechnikov]]></surname>
<given-names><![CDATA[M. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Kuznetsova]]></surname>
<given-names><![CDATA[E. F.]]></given-names>
</name>
</person-group>
<source><![CDATA[Kpfa]]></source>
<year>1990</year>
<publisher-loc><![CDATA[Sverdlovsk ]]></publisher-loc>
<publisher-name><![CDATA[Izd-vo Ural&#8217;skogo universiteta]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Szafraniec]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<source><![CDATA[AcA]]></source>
<year>1960</year>
<volume>10</volume>
<page-range>99</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[van Hamme]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
</person-group>
<source><![CDATA[AJ]]></source>
<year>1993</year>
<volume>106</volume>
<page-range>2096</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[von Zeipel]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
</person-group>
<source><![CDATA[MNRAS]]></source>
<year>1924</year>
<volume>84</volume>
<page-range>702</page-range></nlm-citation>
</ref>
<ref id="B24">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wilson]]></surname>
<given-names><![CDATA[R. E.]]></given-names>
</name>
<name>
<surname><![CDATA[Devinney]]></surname>
<given-names><![CDATA[E. J.]]></given-names>
</name>
</person-group>
<source><![CDATA[ApJ]]></source>
<year>1971</year>
<volume>166</volume>
<page-range>605</page-range></nlm-citation>
</ref>
<ref id="B25">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zasche]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[NewA]]></source>
<year>2016</year>
<volume>42</volume>
<page-range>1</page-range></nlm-citation>
</ref>
<ref id="B26">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zasche]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Liakos]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Wolf]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Niarchos]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[NewA]]></source>
<year>2008</year>
<volume>13</volume>
<page-range>405</page-range></nlm-citation>
</ref>
<ref id="B27">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zola]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Bastürk]]></surname>
<given-names><![CDATA[Ö.]]></given-names>
</name>
<name>
<surname><![CDATA[Liakos]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<source><![CDATA[AJ]]></source>
<year>2016</year>
<volume>152</volume>
<page-range>33</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
