Posts Tagged exoplanets

Stars Give Up Their Planets

Posted by on Thursday, 28 October, 2010



What’s harder to find than an honest politician?

Exactly. A new planet.

The old planets, they’re local. They’re located around our sun. There are now eight of them. Nine for a while but Pluto’s a rock again.

Committee decision.

The first seven weren’t so hard to find. No telescopes needed.

Earth, of course, was easy. Between yer toes.

Mercury, Mars, Venus, Jupiter, Uranus, and Saturn weren’t too bad either. They “wander” in the sky. Stars don’t do that when yer sober.

Big clue.

Uranus, which wasn’t discovered until the 18th century,  took some finding. And the next one, Neptune, did have to wait for telescopes to be invented. Johann Galle gets the credit along with J. J. Leverrier who told him where to point the thing.

J J didn’t like Uranus’ orbit.

“By King Louis Philippe,” he said, “I’d bet my mustache there’s a planet tugging on it and with a couple a mathematical tricks, I think I can figure out where that planet should be.”

“You bite the big one, J J,” said Galle. “You’re not gonna find a planet with mathematics.”

“Just you point your foolish lenses where I tell you, “J J said”, and we’ll see who bites what around here.”

J J was right and that was planet number eight.


Eight planets.

Our solar system was fully mapped. If you wanted more planets, you had best be looking around the good Lord’s firmament.


If you DID look beyond our solar system, what did you see? Stars are bright. Finding a planet around a star is like figuring out who’s in a car coming at you at night with headlights on.

Worse even.

Glare, glare, glare.

How it is.


You can see the star. But any planets would be hidden by its tremendous luminescence.

For a long time – a long, long time, really – we figured there might not BE any other planets anyway. But people – Carl Sagan was one of the most prominent – felt there should be planets elsewhere. Why would our own star, the one we call “sun”,  be so different?

By 1998, astronomers  figured  out a way to detect planets around other stars (exoplanets). Two ways, actually. One way involved watching the star wobble as the planet pulls on it. The other way involved watching a star dim as a planet passed in front.

Kinda sleuthy but it works  well enough to find great big planets, anyway.

A start.

These methods have gotten better with practice. The list of exoplanets is over 400 and growing fast .


Now what if the stars DIDN’T shine so bright? What if you COULD see the planets orbiting other suns?

Can now.

A team led by E Searbyn (Jet Propulsion Laboratory) invented an “Apodizing Phase Plate” which cancels out much of the glare from a star so you can see its planets. With it, they had a clear look at a star (HR8799) and its planets.

Not perfect. Still needs more refining to see the smaller planets. But an amazing piece of science magic anyway.

They say the next version’ll be better yet.

We believe them.

ScienceAintSoBadRating = 10


Image credit: Jet Propulsion Labs


Posted by on Thursday, 12 November, 2009
A Planet-happy Star

A Planet-happy Star

SpaceScience: Stars Give Themselves Away

How do you know if a star has planets?


In fact, it wasn’t until 1995 that we nailed the first such planet (I’m not counting the one we’re standing around on, or its neighbors, of course).

Even “neighboring” stars are so far away and so bright that you can’t really make out their planets with a ‘scope. So two indirect methods are used to find out if a planet’s present: We look for a slight reduction in starlight as a planet passes in front of its star. Or we try to observe the miniscule wobble of the star due to the orbiting planet.

We’ve been, it seems, doing it the hard way.

An article in Nature (lead author, Garik Israelian) says that stars with planets seem to use up more lithium than stars that don’t. The authors figured this out using the European Southern Observatory’s ability to analyze starlight as well as to detect (the hard way) planets.

This is amazingly fantastic news as it will greatly speed the time that we can say, for certain, that the only Republicans in the entire universe are on this planet.*

Very, very nifty piece of work.

ScienceAintSoBadRating = 10

* I’ll make fun of liberals in my next post, OK?