I was reading a news blurb in Astronomy magazine the other day about some new planets discovered around distant stars. Some of these planets are pretty weird.
An important couple of points need to be made first before I talk about the planets. I’ve got to mention that IANAAOAA (I am not an astrophysicist or an astronomer), so everything here is just a lay-persons perspective. From what I understand, scientists are not discovering these weird planets because they are the only type of planets around distant stars. They are finding them because the techniques they currently have will *only* find weird planets. Basically, the only methods they have at the moment to detect the existence of a planet boil down to detecting variations (“wobbles”) in the rotation of the star they are looking at. To make a star wobble enough to detect currently requires an extremely large planet (Jupiter sized or bigger) or a largish planet that is very close to the star. Future detection methods will hopefully allow detection of more typical planets
That said, some of the weird planets they are finding are really weird…
The latest batch are very close their stars…like about 0.028 astronomical units…or about 2.5 million miles. And they are quite large- something like 15 times the size of earth. And they complete a “year” (a full orbit around their sun) in a matter of hours: two to three days. For comparison, Mercury (the closest planet to our Sun) orbits at a distance of 0.38 AU (53 million miles), is a third the size of Earth, and completes one orbit in something like 90 days.
So, here we have a planet 15 times the size of earth that is orbiting its star ten times closer than Mercury does to our Sun [1]. Its travelling around its orbital path at something in the neighborhood of 250,000 miles per hour. If you were on an “earth” in this distant solar system, you’d be seeing the equivalent to the transit of Venus across the sun every few months (I’m guessing on this- the math is a bit beyond me). Except this “venus” in this case would be huge…I can’t quite imagine what it would look like seeing a planet that large that close to its sun as it passes between you and that sun, but I imagine it would be spectactular. This planet is a freak…
But here’s the really weird part. So far, scientists have found three planets pretty much just like this. What this says to me is that there is a huge range of weird and wonderful planetary systems out there, and we have a ton more to learn.