First Four-Exoplanet System Imaged

Phoghat writes "Among the first exoplanet systems imaged was HR 8799. In 2008, a team led by Christian Marois at the Herzberg Institute of Astrophysics in Canada took a picture of the system, directly imaging three giant planets."

Re:Let's not ignore the oceans

[biryokumaru]

Meh, thanks to us, in a few hundred years the oceans will be too acidic for any of those critters to survive. Seems like a safer bets to point ourselves outward in the hopes of avoiding a similar fate for ourselves.

Re:Quite strange.

[AaronParsons]

It is all rather miraculous, how far scientific instrumentation has come, but I'm not quite sure what you're getting at with:

is considered "direct imaging" and is somehow more reliable and more worthy of our trust than the Doppler shifts, wobbles and loss of brightness due to osculation!

This is "direct imaging", because it is directly measuring the spatial distribution of photons arriving from this system, even if it is done with mirrors and CCDs, and not your eye. This sets this measurement apart from the other techniques you have described for inferring the presence of planets from their gravitational pull on the host star.

As for "somehow more reliable", I don't think there's any need for hand-wavy words like "somehow". All of these measurements you mention have error bars (and it should be a crime that any scientific press release be allowed to drop the error bars when reporting). Simultaneously fitting for four separate orbits (including distance from star, mass of planet, inclination of orbit, etc) for this many planets means there is substantial covariance between the parameters you are fitting for. Direct imaging, on the other hand, only has to stand out relative to the noise background. It is hard to judge from the color scale of the images, but these look like easily >5sigma detections of each planet.