New variable star discovered at Emory ObservatoryVariability graph of the star over two nights
On the evening of September 30th, 2007, Horace Dale and his Advanced Astronomy Lab students were measuring brightness changes in a pulsating variable star named V363 Cassiopeiae. They were using a CCD camera attached to the 24 inch reflecting telescope located atop the Math and Science Center. The standard technique when studying variable stars is to compare the brightness of the variable to stars of known magnitude in the camera's field of view and then watch for changes throughout the night. The variable star V363 Casiopeiae had several such comparison stars in the camera's field of view, including one listed in the General Star Catalog as GSC 4014-1629. After analyzing the data, however, Dale noticed a small variation in the brightness of GSC 4014-1629 with a cycle that repeated every 1 hour and 18 minutes. Click to enlarge imageThe black line represents data from the first night. The red line is the data from second night. Finder chart of the variable star
When potentially new variables are found, it is standard practice for astronomers to thoroughly search all the known catalogues and databases for stars that match position and description. Although the star GSC 4014-1629 had been previously catalogued, its variability had not. The next task was for Dale and his class to submit their data to the newly formed International Variable Star Index (VSX) for approval. Moderators with the VSX did an independent catalog search and after analyzing the submitted data confirmed the star as a previously unrecognized variable star. The new variable was given an official preliminary designation of J001528.0+602037 on October 5th, 2007. Click to enlarge imageSince this is a 12th magnitude star, don't count on grabbing your backyard telescope and taking a look. J001528.0 +602037 one is nearly 250 times fainter than the dimmest star you could see with your naked eye in a moonless sky away from city lights. The 24 inch telescope coupled with a CCD detector here at Emory makes an excellent system for studying variable stars down to about 15th magnitude in spite of the light pollution.  Left to Right: Horace Dale, Paul Liebesny, Kenny Patterson, and Jessica Cook Not Pictured: Ivan Antonov "Finding this new variable using our system here at Emory speaks volumes about our capabilities in a light polluted sky...it not only showcases our ability to teach astronomy, but to do research as well" - Horace Dale, Research Associate, Department of Physics For general information about astronomy research at Emory visit: http://www.physics.emory.edu/observatory/observatory.html Article by Richard Williamon, Senior Lecturer, Department of Physics |
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