{
  "id": "1723",
  "title": "Discovery of a variable star",
  "published": "2012-02-20T03:46:19+01:00",
  "url": "http://cieloprofundo.net/2012/02/20/descubrimiento-de-una-estrella-variable/",
  "content": "<p><a href=\"https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/p-final.gif\"><img src=\"https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/p-final.gif\" alt=\"Light-curve graph for Discovery of a variable star\"></a></p><p>The night of January 16 was very special. In images taken to monitor an exoplanet eclipse, I was able to locate a previously uncatalogued variable star, which the AAVSO has designated VSX J083920.0+470411.</p><p>It is an EA variable, an Algol-type eclipsing binary. The graph shows eclipses between the two components of this double star as their orbital plane aligns with our line of sight from Earth. One star is hotter and brighter than the other, producing different changes in brightness as they obscure each other.</p><p>This two-star system has a magnitude of 14.05, falling to 14.60 during eclipses. The stars complete an orbit around each other every 1.55 days, during which we can see two almost equal eclipses as one passes in front of the other.</p><p>To determine all the properties of this variable, I had to observe it over 12 nights, totaling about 50 hours of observation. A total of 1,700 photographs were taken, with exposures between 60 and 120 seconds and a G filter. Three magnitude-11 reference stars were used to calculate the variable&#x27;s differential photometry, using the excellent FotoDif program written by Julio Castellanos. I also thank Ramon Naves for his help throughout the process of submitting the data to the AAVSO.</p><p><a href=\"http://www.aavso.org/vsx/index.php?view=detail.top&amp;oid=278080\">Full observing report</a></p><p><a href=\"https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/variable.jpg\"><img src=\"https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/variable.jpg\" alt=\"Supporting image for Discovery of a variable star\"></a></p>",
  "text": "The night of January 16 was very special. In images taken to monitor an exoplanet eclipse, I was able to locate a previously uncatalogued variable star, which the AAVSO has designated VSX J083920.0+470411.\n\nIt is an EA variable, an Algol-type eclipsing binary. The graph shows eclipses between the two components of this double star as their orbital plane aligns with our line of sight from Earth. One star is hotter and brighter than the other, producing different changes in brightness as they obscure each other.\n\nThis two-star system has a magnitude of 14.05, falling to 14.60 during eclipses. The stars complete an orbit around each other every 1.55 days, during which we can see two almost equal eclipses as one passes in front of the other.\n\nTo determine all the properties of this variable, I had to observe it over 12 nights, totaling about 50 hours of observation. A total of 1,700 photographs were taken, with exposures between 60 and 120 seconds and a G filter. Three magnitude-11 reference stars were used to calculate the variable's differential photometry, using the excellent FotoDif program written by Julio Castellanos. I also thank Ramon Naves for his help throughout the process of submitting the data to the AAVSO.\n\nFull observing report",
  "media": [
    "https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/p-final.gif",
    "https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/variable.jpg"
  ],
  "record": "posts/1723.json",
  "language": "en",
  "kind": "variable-star",
  "graph": "https://cieloprofundo.wordpress.com/wp-content/uploads/2012/02/p-final.gif",
  "source_content_sha256": "1fcc8ff8ac140aa42560817c3b32650022c608136dabc5d99f2c86c73923b08d"
}