The Hubble Space Telescope, 23 years old and allowed to legally drink but not rent cars, has had an exciting couple of days with two new near-Earth discoveries. Both discoveries involve planets, one 63 light-years from Earth, and the other right here in our own solar system.
The first is perhaps the most exciting. Discovered in late 2005, the planet HD 189733 b orbits the star HD 189733 A. That star is an orange dwarf star and the primary star in a binary star system. The secondary star in the system, HD 189733 B, is a red dwarf star. The planet, the only one known in that system, is what is called a “Hot Jupiter”, a gaseous giant that very closely orbits its star; in this case close enough to orbit the star once every 2.2 days, which is 3199 years and 363 days faster than the companion binary star orbits the primary star. Yes, the binary star is so much further out in orbit that it takes 3200 years to take the same trip.
HD 189733 b is about 13% larger than Jupiter, and is tidally locked (one side of the planet always faces the sun, much like how one side of our moon always faces us). Because it’s tidally locked, the temperature difference between the light and the dark side are significant, and cause extreme winds and weather; the winds reach up to 4,350 miles per hour, the temperatures reach more than 1,800 degress Fahrenheit (1,000* Celcius), and rains of hot glass are pretty much the normal. Also interesting, in 2007 HD 189733 b became the second extrasolar planet evidence for water was found, though at such high temperatures any chance of life forming is slim-to-none.
Anyway, what the Hubble most recently discovered this week about lovely HD 189733 b is that it’s blue. And while that doesn’t sound all that fantastic, this is the first time ever that the visible color of an extrasolar planet has ever been directly observed. They still aren’t sure what gives it the blue color, but they describe how they figured out the color;
“We saw the brightness of the whole system drop in the blue part of the spectrum when the planet passed behind its star. From this, we can gather that the planet is blue, because the signal remained constant at the other colors we measured.” -Tom Evans of the University of Oxford, U.K., the leader of the study.
To read into this in more detail, it’s worth clicking through to both NASA’s and Space.com’s articles on the discovery:
That’s no moon, that’s a space statiooo… no, wait, that’s a moon.
The second discovery the Hubble is much, much closer to Earth; Neptune. Using archive photographs from 2004 through 2009, scientists discovered a new moon orbiting our neighboring planet. Named (boringly, and hopefully soon to be renamed something much more interesting) S/2004 N 1, the tiny moon is less than 12 miles across and is so dim that it even escaped notice of the Voyager 2 spacecraft when it flew directly past it in 1989. It sits between the orbits of two other moons, Larissa and Proteus, and travels around its planet once every 23 hours.
Read more about it here:
So there you go. The Hubble, still going strong after all these years. Space nerds rejoice!