When astronauts at NASA began re-checking the old images, which the Hubble Space telescope had captured way back in 1998 ( a good 13 years ago), little did they realize what they were about to stumble upon. The astronauts realized that while analysing the images, back then, they failed to notice an important detail – the existence of two extrasolar planets. While it may have dismayed the astronauts to have missed out on the detail, they've instead chosen to look at the oversight as a benefit. According to an official post on the NASA website, astronauts have benefitted from this late discovery, in the sense that it has given them enough time to study and track the orbital motion of these planets, complete with images.
The 4 planets gradually discovered (Image courtesy: NASA)
So far, it has been known that there are as many as four giant-sized planets orbiting HR 8799, a considerably big star. The HR 8799 is believed to be located 130 light years away. Of the four planets, three were located in 2007 and 2008, when the W.M. Keck Observatory and the Gemini North telescope was used to capture near-infrared ground-based images. The project was initiated with success by Christian Marois of the National Research Council in Canada and his team. Then, a year post the discovery of the three planets in 2008, David Lafreniere of the University of Montreal discovered hidden data (an exoplanet) captured from a Hubble telescope in 1998 using Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
However, the fourth and the last among the planets orbiting the HR 8799 remained unseen because it is on the edge of the NICMOS coronagraphic spot, which blocks light from reaching the central star, and is located 1.5 billion miles away from it.
astronauts, Exoplanet, Gemini North telescope, Hubble, Hubble Space Telescope, NASA, National Research Council in Canada, Near Infrared Camera and Multi-Object Spectrometer, NICMOS, orbit motion, Science and Technology, W.M. Keck Observatory