Its discovery was announced by Scott S. Sheppard , David C. Jewitt , Jan Kleyna , and Brian G. Marsden on May 1 , 2007 , from observations taken between January 18 and April 19 , 2007 . Its discovery was announced by Scott S. Sheppard , David C. Jewitt , Jan Kleyna , and Brian G. Marsden on May 1 , 2007 from observations taken between January 18 and April 19 , 2007 .