Exoplanet Discovery Validation: Old Space Junk Still Making Relevant Discoveries

Thanks to a brand new new imaging technique — new planets have been discovered, for reals, from New Scientist:

THE first direct image of three extrasolar planets orbiting their host star was hailed as a milestone when it was unveiled late last yearMovie Camera. Now it turns out that the Hubble Space Telescope had captured an image of one of them 10 years ago, but astronomers failed to spot it. This raises hope that more planets lie buried in Hubble’s vast archive.
In 1998, Hubble studied the star HR 8799 in the infrared, as part of a search for planets around young and relatively nearby stars. The search came up empty.
Last year, Christian Marois of the Herzberg Institute of Astrophysics in Victoria, British Columbia, Canada, and colleagues looked at the same star using the Gemini North telescope in Hawaii. They discovered three planets, each about 10 times as massive as Jupiter. They succeeded where the Hubble team failed mainly because of new strategies developed to carefully subtract the star’s glare, leaving only the faint infrared glow from its planets.
Marois and David Lafreni√®re, of the University of Toronto in Ontario, Canada, decided to apply their new mathematical tools to the decade-old Hubble image. This involved digitally combining Hubble’s views of 23 similar stars that do not have planets to create a reference image nearly identical to that of HR 8799. When they subtracted the reference image from HR 8799’s, the outermost of its three planets popped into view. (…read more, newscientist.com)

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