Planet-hunting Kepler hits EXOPLANET JACKPOT NASA's exoplanet-hunting Kepler spacecraft has identified a slew of new subjects, adding 26 planets in 11 systems to its inventory. "Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky," said Kepler program scientist Doug Hudgins in a statement announcing the discovery. "Now, in just two years …
the Hubble Deep Field surveys show us 10,000 galaxies (http://hubblesite.org/newscenter/archive/releases/2004/07/). Extrapolate that to the whole sky and ponder - if some of those ancient systems evolved into only a few stable galaxies like ours, then we can easily assume that our universe is teeming with 10^23+ planetary systems that would be supporting some form of life.
And to think, there are still so many humans on our planet that think we are alone and unique here on Earth. I can get my head around the breadth and depth of our universe but can't figure out why so many on this planet aren't willing to give up their dogmas and get on with their one and only life.
"Hudgins didn't elaborate on exactly what he meant by that well-examined patch of sky being a bit larger than your fist, but we can only assume that he's referring to a fist being held at arm's length – and if that's the case, the sky being "positively loaded" with exoplanets may even be a bit of an understatement."
Your fist at arm's length is about 10 degrees wide. Let's say for argument's sake it's 10 degrees high, as well - so your fist covers 100 square degrees (so it is pretty damn close to Kepler's FOV, actually). There are 41,253 square degrees of sky - so Kepler studies approximately 1/410 of the sky.
In that region, it studies 145,000 stars. Let's say 2300 planets is about 2000 stars, accounting for a few multi-planet systems - so of those 145,000 stars, 1 in 73 have had a potential planet come between us and the star 3 times in 3 years (I believe it's 3 transits to be a candidate, anyway - that might be "confirmed", though). Just think of all the planets whose orbits do not come between us and their star (anything more than a few degrees either way); that are far enough out to orbit less than once every year (every planet outside Earth in our solar system); and are too small for Kepler to see (<Earth-ish size).
"Understatement" may be an understatement.
There are currently 755 confirmed planets that have been observed by one method or another, and an additional 1235 candidates from Kepler alone. And those are just the boring candidates that NASA has decided to release. There are as yet more candidates that NASA is holding on to pending additional verification, that are likely to be far more interesting than Jupiter and "Super Jupiter" class planets. I suspect that's where the 2300 figure comes from.
The gentleman above who said that Jupiter is the largest a planet can get is wrong, I'm afraid. they can get much bigger and still not be "failed stars" or whatever the common myth about Jupiter is. There are planets that are 25 times Jupiter's size out there that we've observed.
Further, there are far more multi-planet systems out there than the article indicates. I think the author was talking about just Kepler.
I suggest visiting http://exoplanet.hanno-rein.de/ for a nice visual database of all confirmed planets out there. :)
Are you talking mass or radius here? In terms of mass, above 13 M(Jupiter) you have a brown dwarf. Radius also doesn't increase with mass, much, at that size - you just squash the gas down more (Saturn is half the mass of Jupiter, but only 1/7th smaller in radius). Brown dwarfs at the lower end aren't significantly higher in radius than Jupiter.
If you had a planet 25 times the mass of Jupiter, it's definately a Brown Dwarf. If you have one 25 times the radius, you're larger than the sun.
Nope, we are talking mass.
DH Tau b is a planet, and is 37 times Jupiter's mass. See the link below
http://exoplanet.hanno-rein.de/system.php?id=DH+Tau+b
The entire list is at the link below and can be sorted by mass, which you'll note is measured in how many times of Jupiter's mass. Jupiter is the standard unit of measurement for exoplanets, since the vast majority that we have found are in Jupiter's range or greater. It's easier to detect them when they are that big, and they are definitely not brown dwarf stars, which start at 75 times Jupiter's mass.
http://exoplanet.hanno-rein.de/complete.php
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
