NASA confirmed that it has found evidence for extrasolar planets that were captured by the Hubble telescope in 1998. Back then, the planets escaped the eyes of astronomers, but a recent re-analysis of the infrared image data revealed four huge planets orbiting HR 8799.

In 2007 and 2008, the first three planets were discovered in near-infrared ground-based images taken with the Keck Observatory and the Gemini North telescope, NASA said. A fourth innermost planet was uncovered in 2010. According to NASA, this is the only multiple exoplanetary system for which astronomers have obtained direct photos to date. What makes this discovery special is the fact that the innermost planet circles HR 8799 at a distance of about 1.5 billion miles, but cannot be seen because it is on the edge of Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) “coronagraphic spot that blocks the light from the central star,” NASA said.

The researchers said that the planets were not found back in 1998 as technology had to evolve to reveal them. “When astronomers subtracted the light from the central star to look for the residual glow of planets, the residual light scatter was still overwhelming the faint planets,” NASA said. A method that used images of reference stars, as well as imaging technology that enabled increased contrast and minimized residual light eventually revealed the planets. According to NASA, The planets shown in the image data have only about 1/100,000th the brightness of their parent star when viewed in near-infrared light.

HR 8799 is about 130 light years from Earth.

According to the data published, the three outer gas-giant planets take about 100, 200 and 400 years to orbit HR 8799. The outermost planet has “barely moved” over a 10-year period, said Remi Soummer of the Space Telescope Science Institute in Baltimore.