The same day astronomers announced the discovery of Fomalhaut b seen in the previous two pictures, they had another surprise: the first picture of an actual exoplanet solar system!
They found not one but three
planets orbiting the star HR 8799, a slightly hotter and more massive star than the Sun, located about 130 light years away. The star is about 60 million years old. The brilliant light from the star has been masked out to show the much fainter planets.
The planets, labeled b, c, and d, are about 7, 10, and 10 times the mass of Jupiter, respectively, and orbit their star at 68, 38, and 24 times the distance of the Earth from the Sun.
HR 8799 b is clearly a planet, but the other two have masses uncertain enough that they might barely qualify as brown dwarfs. However, models of the system show that if the planets really are
more massive, their mutual gravity would destabilize the system. It's likely then they are closer to the lighter end, making them planets as well.
This picture qualifies as another first as well: the first one taken from the ground
of planets around a sun-like star. The first exoplanet was seen orbiting a brown dwarf, and the Fomalhaut pictures were taken from space, using Hubble. What this picture meant is that it was possible to take high-contrast, high-resolution images using ground-based observatories, which are far easier to manage and are far easier and cheaper to build than space observatories. It promised to usher in a new age of planetary detection.Original blog post: HUGE EXOPLANET NEWS ITEMS: PICTURES!!!Credit: Gemini Observatory