A WARM APPETIZER: On the hunt for cool, low-mass planets, which may take years to identify, Kepler needed little time to find much more massive planets kept scorching hot by their host stars. Above, an artist's conception of one such "hot Jupiter."
Image: NASA/JPL-Caltech/T. Pyle (SSC)
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Astronomers have filled in more details in the picture of the Milky Way Galaxy, unveiling five previously unknown planets outside our solar system that were detected via early data from NASA's planet-seeking Kepler spacecraft. A team of researchers reported the planet findings Monday at a meeting of the American Astronomical Society and in a paper to be published online Thursday in Science.
Kepler launched in March to seek out worlds like our own—terrestrial planets orbiting sunlike stars at a temperate distance where liquid water could persist. And although that search will likely take years, the spacecraft was able to pick out five larger, hotter planets in its first 43 days of observations.
Trailing Earth in an orbit around the sun, Kepler monitors the brightness of about 150,000 stars, looking for periodic dimming that might be caused by a planet passing in front of its star. The spacecraft initially identified 175 possible planetary systems for follow-up observation from the ground, says Kepler co-investigator Natalie Batalha, a professor of physics and astronomy at San Jose State University.
With 85 nights of observations on mid-size telescopes across the globe and 11 nights on one of the powerful 10-meter Keck telescopes atop Mauna Kea in Hawaii, the Kepler team thoroughly checked out 50 of those possible planetary systems, Batalha says. From the ground, the researchers looked for Doppler shifts in the suspect stars' light spectra that would reveal a gravitational wobble induced by an orbiting planet. Many were false positives, such as gravitationally bound binary stars eclipsing one another, but the five previously unknown planets emerged. As for the other 125 candidates, follow-up work is ongoing. "A bottleneck right now is having enough telescope time to follow up on all these interesting candidates that we have," Batalha says.
The five planets in the new Kepler results are all giants, with masses ranging from about 25 to 670 Earths. (The least massive, Kepler 4b, is roughly 1.4 times the mass of Neptune.) They are scorching, too—each planet's host star is about as hot as the sun, but the Kepler planets' orbits hug their stars so tightly that they complete a revolution in less than five days. For comparison, Mercury, the innermost planet in the solar system, takes 88 days to circle the sun.
The short orbital periods of the newfound planets enabled their detection from the small data set—each planet passed its star several times in the 43-day observation window, dimming the starlight by a small fraction with each orbit. Observing multiple orbits of cooler planets with longer orbital periods will take much more time. To find a true Earth analogue orbiting a sunlike star at about the same distance separating Earth from the sun—in other words, an Earth-size world with an orbital period of about one year—the Kepler team estimates that it will need about three years of observations from the spacecraft.
To complicate matters further, a planet of roughly Earth size would dim its host star only slightly and would induce very little wobble in the star, making identification and follow-up confirmation more difficult.
Habitable Earth-size planets might turn up sooner around smaller, cooler stars in Kepler's field of view, where water could persist on closer-orbiting planets that would complete laps around their host stars more quickly. But even so, exoplanet enthusiasts shouldn't expect pay dirt too soon—follow-up observations of any exo-Earth will be tricky and time-consuming. "The smaller the planet is, the harder it is to confirm," Batalha says. "It takes more telescope time. We'll be very careful with those."
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19 Comments
Add Commentto JOHN MATSON; I alwas wounder with my mom when i was younger about sending a ship with a huble like telascope on it to the dark region of our systen and on it,s way it would eject several satellite monitors to pick up the ships signal to keep a strong as it passes info to the other monitors so you could get the datd alot fsater and send your instructions faster.. i alway wounder why NASA never did this on the Mars mission. wouldn't it make it a faster process for info and or to controll your crafts on other plants faster?? B F HENDERSON JR
Reply | Report Abuse | Link to thisto JOHN MATSON; I alwas wounder with my mom when i was younger about sending a ship with a huble like telascope on it to the dark region of our systen and on it,s way it would eject several satellite monitors to pick up the ships signal to keep a strong as it passes info to the other monitors so you could get the datd alot fsater and send your instructions faster.. i alway wounder why NASA never did this on the Mars mission. wouldn't it make it a faster process for info and or to controll your crafts on other plants faster?? B F HENDERSON JR
Reply | Report Abuse | Link to thisHey BF...1) no need to send a telescope elsewhere in the solar system, once you get outside the earth's atmosphere it's dark enough. Plus if you sent the telescope far away, it would be more difficult and expensive to send people to work on it (like was done with Hubble)
Reply | Report Abuse | Link to this2) as far as communication with remote probes, the speed of light is the limiting factor, so having several intermediate satellites passing on the signal would actually slow things down
Sounds like you are in school, you should study Physics and work on your spelling/grammar!!
The data would not transfer faster since it's still limited by the speed of light. Your suggestion WOULD, however, increase the signal if used simply as relays. It might also bring the possibility of increasing bandwidth due to eliminating potential signal degradation.
Reply | Report Abuse | Link to thisI'm sure the main reason it hasn't been tried is cost. Something like that significantly increases the complexity of a mission, and when you increase complexity, you increase cost dramatically.
The biggest advantage I can see to a relay network would be the elimination of line-of-sight requirements for data transfer. That's really about it, though, and it's definitely too expensive to be considered feasable at this time.
Reply | Report Abuse | Link to thisYou might want to consider faster than light communications using entanglement of photons,looking for wave function drop from same distance stars from Earth,that from Earth type systems that Kepler finds.If someone else out there is watching, the wave drop would occur even if they don't know why,but we, knowing about entanglement would,and hopefully in the future they would too.
Reply | Report Abuse | Link to thisHas anyone read Orson Scott Card, yet? (ahem)
Reply | Report Abuse | Link to thisWhy are we studying planets 100's of lightyears away? Why don't we begin mapping our neareast neighbors to the best of our ability? Take the nearest hundred stars and find out as much about them as we can. After all, those may be the ones we could someday get to.
Contributions by hubble makes humans humble.More Exoplanets.More Galaxies which are to be occupied or visited by humans!!!
Reply | Report Abuse | Link to thisThank you Michael for your suggestions,life might be closer than we think,maybe but a few light years away.I agree that we should study the closest stars to the best of are ability,after all they were likely born the same time our sun was.
Reply | Report Abuse | Link to thisInteresting stuff. However, i keep wondering if there are more intelligent being out there and why have they not found us yet. The universe is too big for us to be its only occupants.
Reply | Report Abuse | Link to thisAfter a decade and a half of observing wobbles and occultations and finding mostly hot Jupiters they must be able to extract some kind of pattern relating to the class and location of stars that have them. Maybe there's an article somewhere that has done that.
Reply | Report Abuse | Link to thisThey're probably close to the technical limit [except for more years of data collecting] of the wobble and occultation approach. What's the prospect of [for example] optical imaging with space-based, large-baseline stereo telescopes? Can anyone point to information on plans inside NASA, ESA, Japan, China or Russia for such things, even if they're just cost/feasibility studies?
And while we're here talking about it, the claim is being debunked at "Follow up Observations..." in another article here on Jan 6! Some were already known and some have been determined to be dwarf brown stars.
Reply | Report Abuse | Link to thisHas NASA lost all credibility or what? Please, Mr. President provide some leadership in this arena.
My guess that the difference between a large hot Jupiter and a dwarf brown star would be a matter of degree rather than kind.
Reply | Report Abuse | Link to thisWhat cannot be addressed at this time is whether a hot Jupiter (or brown dwarf) at the proper distance from its sun might have its own moon that would be an earth like planet, and what the fact of an orbit like that would have on what for us is a diurnal system, but for such a place could be very complicated.
My guess that the difference between a large hot Jupiter and a dwarf brown star would be a matter of degree rather than kind.
Reply | Report Abuse | Link to thisWhat cannot be addressed at this time is whether a hot Jupiter (or brown dwarf) at the proper distance from its sun might have its own moon that would be an earth like planet, and what the fact of an orbit like that would have on what for us is a diurnal system, but for such a place could be very complicated.
I have a suspicion that only we did observed in case the five recognitions that those're sunspots on the surfaces the stars because of short revolution times (3-4 days!) So those are exoplanets not but those're revolution times of the stars.
Reply | Report Abuse | Link to thisEmery
Over at the planetary / astronomers gathering report by G. Musser in Washington, it says that an astronomer has studied the outputs from several hundred yellow stars like the sun and found that the sun has many more incidents of radiation outbursts than the majority (Less than 1% are as active and the majority of the rest are extremely quiescent) Add another factor to the Drake probability of life equation: the sun has to have outbursts which could cause mutations (Darwin is sinking into the sunset very quickly, natural selection indeed!) To be where we are now is not "natural". It is the result of unique circumstances. Come on, we've identified over fifteen variables that all have to be met or no go on intelligent life, let alone advanced intelligent life.
Reply | Report Abuse | Link to thisDarkside: We as a species are only just beginning to explore space. It took Earth billions of years to produce sentient life, yet Earth is neither a very old or very young planet in galactic terms. If Earth is average in terms of time to produce sentient life and if sentient life is likely to eventually evolve on many planets then we can only assume many alien civilizations have evolved and matured long before ours has. But we have only been capable of receiving radio signals for a hundred years or so... what are the odds that any of these civilizations would have developed this technology within the same window of time as ours. We can only assume that such technologies will seem primitive indeed to more advanced aliens, so there is probably a rather small chance we would be able to detect alien civilizations even if they're out there. My guess is that older alien civilizations will have developed technologies necessary to travel to the stars. If so they no doubt would eventually check out Earth as a likely candidate planet (we're close to being able to detecting extrasolar earth like planets so why shouldn't they be able to?). So, perhaps they visited us before we were advanced enough to bother interacting with (this may still be the case now) or perhaps they visited us but have no interest in affecting our evolution. I suspect the latter is a likely scenario for more advanced civilizations (though who can tell with aliens?). But with more advanced technologies why do we think we'd be able to detect them if they had no interest in making themselves known to us? For all we know, the University of Beta Centauri has a whole program on Earth Studies.
Reply | Report Abuse | Link to thisWho knows? Fun to speculate, tho.
Just wondering, is there anyway that information can be sent on photons or electrons along [entanglement lines(?)] without changing the atoms themselves. If the problem with entanglement communications being that the two atoms need to be the same and so if one atom 'knows' the answer then the other must already know it for the two atoms to be entangled. Can one communicate with the other with electromagnetic radiation without changing the atoms themselves in any way?
Reply | Report Abuse | Link to thisplease email me the answers at e.cao117@hotmail.com
Also just wondering, scientist havn't catalogued the kuiper belt or Oort cloud very well. Wouldn't the bodys out there interupt with the data Kepler is recieving. Is it possible that kepler has mistaken a close-orbit planet for a rock only one light year out in the Oort cloud? how do scientists correct for this
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