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4-inch Telescope Finds New Planet
serutan writes "After a backyard astronomy size telescope first tracked the periodic dimming of a star 500 light-years away, the Keck I telescope in Hawaii later confirmed that a Jupiter-size planet orbits the star. A press release from Harvard gives details. This is the first result of the Trans-Atlantic Exoplanet Survey, a project using small telescopes and cheap equipment to search for extrasolar planets. "
The Telescope did NOT find this planet. The Software did.
Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
Yes -- thats why there's plans for a space telescope in the next 10 or 20 years to look specifically for terrestrial planets.
also, jovian planets are good info too. One strong hypothesis is that life couldnt exist on earth without a big planet (jupiter) out there sweeping up most of the space junk (asteroids, comets, etc) that comes falling into the solar system. Big planets help out the inner planets by keeping collisions down.
Moo.
Although it is Uranus-sized, it is close to the star, and so it may not be similar.
ESO press release: http://www.eso.org/outreach/press-rel/pr-2004/pr-2 2-04.html
Will this method help find smaller planets?
Almost certainly not. The amplitude of the brightness variations, caused by the transit of a terrestrial planet, varies as the square of the ratio between the radius of the star and the planet. For the Sun/Earth values, this figure comes out as a 0.008% variation in brightness, or -- in astronomical terms -- a change of 0.2 millimagnitudes.
Measuring such small changes is extremely difficult, even using very large (5-10m) ground-based telescopes that have fancy optics and a high throughput. That's why terrestrial planet finding using the transit method will have to wait for NASA's Kepler mission. Scheduled for launch in 2007, this mission will look for minute brightness variations in c. 100,000 nearby Solar-type stars.
Tubal-Cain smokes the white owl.
I think it's mostly down to the fact that these large planets close to their parent stars are easier to see.
If you're looking at a Jupiter-sized object that orbits closer than Mercury, then you're going to have an orbital period on the order of days or weeks. On the other hand, if you want to detect a Jupiter-sized object orbiting at that same distance Jupiter does from our Sun, then your orbital period ends up as years or tens of years (Jupiter completes one orbit in a bit less than twelve years.)
Depending on the technique you use to detect a planet, you often need to show a pattern that persists through at least two or three consecutive orbits.
In the case discussed here, very small changes in brightness (less than 1%) were observed every time there was a transit (the planet passed between us and the other star); these events took place every three days. In principle, one could get sufficient data in a week or so. If we were looking at an object with an orbit like Jupiter's, we'd need to have at least a quarter century of careful monitoring of the star. Other techniques also require significantly more data collection time or more sensitive equipment as the planets get smaller and their orbits grow longer. The reason why we're detecting massive gas giants in close orbits is because they're the easiest planets to see. We're definitely not getting a random sample of all planets.
Yes, the planets we are seeing seem unusual, but they're still quite few in absolute number. Perhaps in twenty years when we can reliably start detecting rocky, Earth-type planets in Earth-type orbits we'll be able to make more definitive statements. Right now we're like biologists trying to understand human life--but only being allowed to study specimens weighing more than 600 lbs.
~Idarubicin