<?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>S0185-11012019000200221</article-id>
<article-id pub-id-type="doi">10.22201/ia.01851101p.2019.55.02.10</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Some remarks on the open cluster upgren 1 using uvby &#8722; &#946; photoelectric photometry]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Peña]]></surname>
<given-names><![CDATA[J. H.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
<xref ref-type="aff" rid="A a"/>
<xref ref-type="aff" rid="A4"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rentería]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Huepa]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Pani]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af2">
<institution><![CDATA[,Universidad Nacional Autónoma de México Instituto de Astronomía ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad Nacional Autónoma de México Observatorio Astronómico Nacional de Tonantzintla ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af4">
<institution><![CDATA[,Universidad Nacional Autónoma de México Facultad de Ciencias ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2019</year>
</pub-date>
<volume>55</volume>
<numero>2</numero>
<fpage>221</fpage>
<lpage>229</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0185-11012019000200221&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0185-11012019000200221&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0185-11012019000200221&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT The open cluster Upgren 1 presents peculiar features that in the past led to divergent opinions about its existence. In previous studies of other clusters, uvby &#8722; &#946; photoelectric photometry has shown results in agreement with other techniques; therefore, the photometry obtained in the present work has been combined with data from previous studies to examine the brightest stars in the direction of the cluster. Analyzing the unreddened indexes, we found that all the stars are of late spectral types. Applying the empirical relations of Nissen (1987) to determine the reddening and, consequently, the unreddened indexes, we found that all but three are located at a distance of 123 ± 17 pc. The assigned membership in this study is in concordance with that of Upgren, Philip and Beaver (1982) obtained through radial velocities.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN El cúmulo abierto Upgren 1 presenta características muy particulares que hacen que las investigaciones lleguen a conclusiones divergentes sobre su existencia. Debido a que en el pasado la fotometría fotoeléctrica uvby &#8722; &#946; ha probado ofrecer resultados acordes con otras técnicas, la hemos conjuntado con estudios previos con la misma fotometría para estudiar las estrellas más brillantes en la dirección del cúmulo. Mediante el analisis de los índices desenrojecidos hemos encontrado que todas las estrellas son del tipo tardío. Aplicando las calibraciones empíricas de Nissen (1988) para determinar el enrojecimiento y, por ende, los índices desenrojecidos, encontramos que todas, salvo tres, son estrellas agrupadas a una distancia de 123 ± 17 pc. La membresía asignada a este estudio está en concordancia con el trabajo de Upgren, Philip and Beaver (1982) obtenido por una técnica totalmente diferente, mediante velocidades radiales.]]></p></abstract>
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