It may seem indescribably arrogant, but after observing exactly one planetary system (ours), astronomers have already figured out what to expect elsewhere. These expectations reflect observations of stellar evolution, patterns in our solar system and the current theory of how planets probably form from a protoplanetary nebula (defined).
Jupiter © NASA.
According to David Black of the Lunar and Planetary Institute, these are the standard specs for a planetary system:
Further conforming to our present understanding of planetary formation, the new-found object orbits Lalande 21185 at about the distance of the asteroid belt (defined) from our sun. "We'd expect to find the giant planets in the cool regions," says Black, where the gases that comprise them can condense. (Gatewood was less certain of an object that would orbit closer in, with about a 6 year orbit.)
Why doesn't somebody just point a telescope at a star and take a picture of its planets?
Probably the most exciting, and credible aspect of the faint but regular signal from Lalande 21185 is that it confirms this picture, Black adds. "In my view, George [Gatewood] was properly circumspect," since the signal was so tiny, "but for me, this is the first [announcement of the discovery of a planet] that has some vague resemblance to what planetary systems ought to look like."
