In November 2008, astronomers using the Keck and Gemini telescopes imaged three orbiting companions to star HR8799, which is approximately 150 light years from Earth. Astronomers have revisited these planets and directly imaged them using a small, ground-based telescope. Small is a relative term, of course. They used a 1.5-meter telescope to look at the planets. That is the equivalent of a 59 inch telescope, which is out of the range of just about all amateur astronomers, although you could buy a monster 50 inch Dobsonian from Orion Telescopes for a mere $123,000.

One key here is that they used a “portion” of the telescope. The Hale telescope is 200 inches. Another key item is that they used adaptive optics to take the distortion out of the atmosphere. Finally, they used a coronagraph to mask out the light from the star, but not from the planets.

Personally, I would like to know what the remaining blue smudges in the image are.

This picture was taken using a small, 1.5-meter (4.9-foot) portion of the Palomar Observatory’s Hale Telescope, north of San Diego, Calif. This is the first time a picture of planets beyond our solar system has been captured using a telescope with a modest-sized mirror — previous images were taken using larger telescopes.

The three planets, called HR8799b, c and d, are thought to be gas giants like Jupiter, but more massive. They orbit their host star at roughly 24, 38 and 68 times the distance between our Earth and sun, respectively (Jupiter resides at about 5 times the Earth-sun distance).

Image credit: NASA/JPL-Caltech/Palomar Observatory

NASA – Small, Ground-Based Telescope Images Three Exoplanets.