Kepler

The cosmos at our fingertips.
Post Reply
Doum
A personalized rank.
Posts: 525
Joined: Fri Feb 18, 2005 5:38 pm

Re: Kepler

Post by Doum » Tue Jan 08, 2013 3:42 am

At Least One in Six Stars Has an Earth-Sized Planet, Analysis Finds.........
......Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there.

http://www.sciencedaily.com/releases/20 ... 162220.htm

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

CfA: At Least One in Six Stars Has an Earth-sized Planet

Post by bystander » Tue Jan 08, 2013 5:31 am

Doum wrote:At Least One in Six Stars Has an Earth-Sized Planet, Analysis Finds.........
......Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there.

http://www.sciencedaily.com/releases/20 ... 162220.htm

At Least One in Six Stars Has an Earth-sized Planet
Harvard-Smithsonian Center for Astrophysics | 2013 Jan 07
The quest for a twin Earth is heating up. Using NASA's Kepler spacecraft, astronomers are beginning to find Earth-sized planets orbiting distant stars. A new analysis of Kepler data shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury. Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there.

Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics (CfA), presented the analysis today in a press conference at a meeting of the American Astronomical Society in Long Beach, Calif. A paper detailing the research has been accepted for publication in The Astrophysical Journal.

Kepler detects planetary candidates using the transit method, watching for a planet to cross its star and create a mini-eclipse that dims the star slightly. The first 16 months of the survey identified about 2,400 candidates. Astronomers then asked, how many of those signals are real, and how many planets did Kepler miss?

By simulating the Kepler survey, Fressin and his colleagues were able to correct both the impurity and the incompleteness of this list of candidates to recover the true occurrence of planets orbiting other stars, down to the size of Earth.

"There is a list of astrophysical configurations that can mimic planet signals, but altogether, they can only account for one-tenth of the huge number of Kepler candidates. All the other signals are bona-fide planets," says Fressin.

Most sun-like stars have planets

Altogether, the researchers found that 50 percent of stars have a planet of Earth-size or larger in a close orbit. By adding larger planets, which have been detected in wider orbits up to the orbital distance of the Earth, this number reaches 70 percent.

Extrapolating from Kepler's currently ongoing observations and results from other detection techniques, it looks like practically all Sun-like stars have planets.

The team then grouped planets into five different sizes. They found that 17 percent of stars have a planet 0.8 - 1.25 times the size of Earth in an orbit of 85 days or less. About one-fourth of stars have a super-Earth (1.25 - 2 times the size of Earth) in an orbit of 150 days or less. (Larger planets can be detected at greater distances more easily.) The same fraction of stars has a mini-Neptune (2 - 4 times Earth) in orbits up to 250 days long.

Larger planets are much less common. Only about 3 percent of stars have a large Neptune (4 - 6 times Earth), and only 5 percent of stars have a gas giant (6 - 22 times Earth) in an orbit of 400 days or less.

Smaller planets aren't picky

The researchers also asked whether certain sizes of planets are more or less common around certain types of stars. They found that for every planet size except gas giants, the type of star doesn't matter. Neptunes are found just as frequently around red dwarfs as they are around sun-like stars. The same is true for smaller worlds. This contradicts previous findings.

"Earths and super-Earths aren't picky. We're finding them in all kinds of neighborhoods," says co-author Guillermo Torres of the CfA.

Planets closer to their stars are easier to find because they transit more frequently. As more data are gathered, planets in larger orbits will come to light. In particular, Kepler's extended mission should allow it to spot Earth-sized planets at greater distances, including Earth-like orbits in the habitable zone.

Nearly All Sun-Like Stars Have Planetary Systems
Universe Today | Nancy Atkinson | 2013 Jan 07

Earth-Sized Alien Worlds Orbit One in Six Stars
Discovery News | Irene Klotz | 2013 Jan 07

Earth-size planets common in galaxy
University of California, Berkeley | 2013 Jan 08

Earth-Sized Planets Widespread in Galaxy
Centauri Dreams | Paul Gilster | 2012 Jan 08
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

UCB: Exocomets may be as common as exoplanets

Post by bystander » Tue Jan 08, 2013 6:23 am

Exocomets may be as common as exoplanets
University of California, Berkeley | Robert Sanders | 2013 Jan 07
Image
Artistic depiction of dust and comets around the young star Beta Pictoris
as seen from the outer edge of its disk. (Credit: NASA/Lynette Cook)

Comets trailing wispy tails across the night sky are a beautiful byproduct of our solar system’s formation, icy leftovers from 4.6 billion years ago when the planets coalesced from rocky rubble.

The discovery by astronomers at the University of California, Berkeley, and Clarion University in Pennsylvania of six likely comets around distant stars suggests that comets – dubbed “exocomets” – are just as common in other stellar systems with planets.

Though only one of the 10 stars now thought to harbor comets is known to harbor planets, the fact that all these stars have massive surrounding disks of gas and dust ‑ a signature of exoplanets – makes it highly likely they all do, said Barry Welsh, a research astronomer at UC Berkeley’s Space Sciences Laboratory.

“This is sort of the missing link in current planetary formation studies,” Welsh said. “We see dust disks – presumably the primordial planet-forming material – around a whole load of stars, and we see planets, but we don’t see much of the stuff in between: the asteroid-like planetesimals and the comets. Now, I think we have nailed it. These exocomets are more common and easier to detect than people previously thought.”

Welsh will present the findings on Monday, Jan. 7, during a meeting of the American Astronomical Society in Long Beach, Calif. Three of the new exocomets were reported in the Oct. 2012 issue of the journal Publications of the Astronomical Society of the Pacific by Welsh and colleague Sharon L. Montgomery of the Department of Physics at Clarion University.

Welsh also will participate in a media briefing on Tuesday, Jan. 8, at 2:30 p.m. PST in Room 204 on Level 2 of the Long Beach Convention Center.

Welsh summarized the current theory of planet formation as “interstellar dust under the influence of gravity becomes blobs, and the blobs grow into rocks, the rocks coalesce and become bigger things – planetesimals and comets – and finally, you get planets.”

Many stars are known to be surrounded by disks of gas and dust, and one of the closest, beta-Pictoris (β-Pic), was reported to have comets in 1987. In 2009, astronomers found a large planet around β-Pic about 10 times larger than Jupiter. Three other stars – one discovered by Welsh in 1998 – were subsequently found to have comets.

“But then, people just lost interest. They decided that exocomets were a done deal, and everybody switched to the more exciting thing, exoplanets,” Welsh said. “But I came back to it last year and thought, ‘Four exocomets is not all that many compared to the couple of thousand exoplanets known – perhaps I can improve on that.’”

Detecting comets may sound difficult – after all, the snowballs are typically only 5-20 kilometers (3-13 miles) in diameter. But Welsh said that once comets are knocked out of their parking orbit in the outer reaches of a stellar system and fall toward a star, they heat up and evaporate. The evaporating comet, which is what we see with comets such as Halley and next year’s highly anticipated Comet ISON, creates a brief, telltale absorption line in the spectrum of a star.

The six new exocomet systems were discovered during three five-night-long observing runs between May 2010 and November 2012 using the 2.1-meter telescope of the McDonald Observatory in Texas. The telescope’s high resolution spectrograph revealed weak absorption features that were found to vary from night to night, an outcome that Welsh and Montgomery attributed to large clouds of gas emanating from the nuclei of comets as they neared their central stars.

All of the newly discovered exocomets – 49 Ceti (HD 9672), 5 Vulpeculae (HD 182919), 2 Andromedae, HD 21620, HD 42111 and HD 110411 – are around very young type A stars, which are about 5 million years old, because Welsh’s detection technique works best with them. With a higher resolution spectrograph, he might be able to detect comets around the older and yellower G and F stars around which most exoplanets have been found.

Nevertheless, all evidence suggests that these dusty A stars should have planets, and planets are the only thing that could knock a comet out of its orbit and make it fall toward its star.

“If it quacks, waddles and has feathers, then it’s probably a duck,” he said.

Detection of Variable Gaseous Absorption Features in the Debris Disks Around Young A-type Stars - Sharon L. Montgomery, Barry Y. Welsh
  • Publications of the Astronomical Society of the Pacific 124(920) 1042 (2012 Oct 18) DOI: 10.1086/668293

Alien Comets Swarm Around Other Stars
Slate Blogs | Bad Astronomy | 2013 Jan 07
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Oxford: 'Traffic jam' of moons in habitable zone

Post by bystander » Tue Jan 08, 2013 6:34 am

'Traffic jam' of moons in habitable zone
University of Oxford | 2013 Jan 07
Volunteers from the Planethunters.org website, part of the Oxford University-led Zooniverse project, have discovered 15 new planet candidates orbiting in the habitable zones of other stars.

Added to the 19 similar planets already discovered in habitable zones, where the temperature is neither too hot nor too cold for liquid water, the new finds suggest that there may be a 'traffic jam' of all kinds of strange worlds in regions that could potentially support life.

Rather than being seen directly, the new planet candidates were found by Planethunters.org volunteers looking for a telltale dip in the brightness as planets pass in front of their parent stars. One of the 15, a Jupiter-sized planet orbiting a Sun-like star, has been officially confirmed as a planet (with 99.9% certainty) after follow-up work done with the Keck telescope in Hawai'i and has been named 'PH2 b'. It is the second confirmed planet to be found by Planethunters.org.

A report of the research has been submitted to the Astrophysical Journal and is released via arxiv.org on Monday 7 January 2013.

'There's an obsession with finding Earth-like planets but what we are discovering, with planets such as PH2 b, is far stranger,' said Zooniverse lead Dr Chris Lintott of Oxford University. 'Jupiter has several large water-rich moons - imagine dragging that system into the comfortably warm region where the Earth is. If such a planet had Earth size moons, we'd see not Europa and Callisto but worlds with rivers, lakes and all sorts of habitats - a surprising scenario that might just be common.'

Planethunters lead scientist Professor Debra Fisher of Yale University said: 'We are seeing the emergence of a new era in the Planet Hunters project where our volunteers seem to be at least as efficient as the computer algorithms at finding planets orbiting at habitable zone distances from the host stars. Now, the hunt is not just targeting any old exoplanet - volunteers are homing in on habitable worlds.'

Lead author Dr Ji Wang, also of Yale University, said: 'We can speculate that PH2 b might have a rocky moon that would be suitable for life. I can't wait for the day when astronomers report detecting signs of life on other worlds instead of just locating potentially habitable environments. That could happen any day now.'

More than 40 volunteers are acknowledged in the paper for their contributions to the work. Among them is Roy Jackson, a 71-year-old retired police officer who lives in Birtley, near Gateshead. He said: 'It is difficult to put into words, the pleasure, wonderment and perhaps even pride that I have in some small way been able to assist in the discovery of a planet. But I would like to say that the discovery makes the time spent on the search well worth the effort.'

Mark Hadley, an electronics engineer from Faversham, another of the Planet Hunters credited on the paper, said: 'Now, when people ask me what I achieved last year I can say I have helped discover a possible new planet around a distant star! How cool is that?'

Dr Chris Lintott said: 'These are planet candidates that slipped through the net, being missed by professional astronomers and rescued by volunteers in front of their web browsers. It's remarkable to think that absolutely anyone can discover a planet.'

Within ‘habitable zone,’ more planets than we knew
Yale University | 2013 Jan 07

The number of known places in our galaxy theoretically hospitable to life may be significantly greater than previously thought, according to new research.

Researchers with Planet Hunters are reporting the discovery of a Jupiter-sized planet in the so-called “habitable zone” of a star similar to Earth’s sun, as well as the identification of 15 new candidate planets also orbiting within their star’s habitable zone.

Within the zone, atmospheric temperatures range from -126 to 86 degrees Fahrenheit. The scientists say a rocky planet there with a greenhouse atmosphere could have pools of liquid water, and thus the possibility of life. The discovery of the new candidate planets nearly doubles the number of gas giant planet candidates known to be orbiting within the habitable zones of solar stars.

“This is just a first step toward finding a habitable world elsewhere,” said Ji Wang, a postdoctoral researcher at Yale and lead author of a paper about the new discoveries. “Any moon around this newly discovered, Jupiter-sized planet might be habitable. It’s very similar to what was depicted in the movie ‘Avatar’ — the habitable moon Pandora around a giant planet, Polyphemus.”

The paper is available on the Planet Hunters website and has been submitted to The Astrophysical Journal. Researchers are scheduled to present the results at the 221st meeting of the American Astronomical Society in Long Beach, Calif., Jan. 6-10.

Conditions on the new planet, gas giant PH2 b, and the 15 candidate planets probably could not support life, given their largely gaseous state, the astronomers said. But they could have rocky satellites that would.

Planet Hunters is a joint project of Yale University and several other institutions. It enlists volunteers to help professional astronomers detect planets outside Earth’s solar system by sifting massive amounts of data gathered by NASA’s Kepler spacecraft. Professional scientists review the most promising findings. Worldwide, more than 200,000 volunteers have participated since 2010.

The latest findings also establish that Planet Hunters’ volunteers are effective detectors of long-period planet candidates, or those residing in or near a habitable zone, the paper’s authors said.

“We are seeing the emergence of a new era in the Planet Hunters project where our volunteers seem to be at least as efficient as the computer algorithms at finding planets orbiting at habitable-zone distances from the host stars,” said Debra Fischer, a Yale astronomy professor and co-founder of Planet Hunters.

In all, the new paper reports the discovery of one confirmed planet, PH2 b, and 42 candidate planets. Of these, at least 15 appear to be orbiting in their star’s habitable zone, researchers said.

Astronomers on the Planet Hunters team declared PH2 b to be a bona fide planet with a confidence level of 99.92%.

Since its establishment, Planet Hunters has reported finding a total of 48 previously unknown candidate planets. PH2 b is its second confirmed planet. The first, PH1, was reported in October.

Planet Hunters volunteers typically find candidate planets by identifying faint dips in light caused by planets as they pass in front of their host stars. In this case, professional scientists also used high-resolution spectrograph and adaptive optics to rule out false positive detections and to calculate confidence levels for their findings.

Kian Jek of San Francisco, a lead volunteer on the project, described himself as “someone who grew up with the Apollo moon landings, whose childhood imagination was fired by Kubrick's ‘2001’ and the original ‘Star Trek.’”

“I never had any doubt that planets around other stars existed and that one day we would discover them,” he continued. “But I never dreamed that we would find them in my lifetime, let alone that I would be involved in their discovery. Planet Hunters is an exciting project that allows citizens and scientists to participate in pushing ‘the final frontier’ ever slightly further.”

Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data - Ji Wang et al
Exciting Potential for Habitable ExoMoons
Universe Today | Nancy Atkinson | 2013 Jan 07
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Leibnitz: Life Possible on Extrasolar Moons

Post by bystander » Sun Jan 13, 2013 2:10 am

Life Possible on Extrasolar Moons
Leibniz Institute for Astrophysics | 2013 Jan 10

In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets.

[attachment=0]exomoon.jpg[/attachment][/i]
The research, conducted by René Heller of Germany's Leibniz Institute for Astrophysics Potsdam and Rory Barnes of the University of Washington and the NASA Astrobiology Institute, will appear in the January issue of Astrobiology.

About 850 extrasolar planets — planets outside the solar system — are known, and most of them are sterile gas giants, similar to Jupiter. Only a few have a solid surface and orbit their host stars in the habitable zone, the circumstellar belt at the right distance to potentially allow liquid surface water and a benign environment.

Heller and Barnes tackled the theoretical question whether such planets could host habitable moons. No such exomoons have yet been discovered but there's no reason to assume they don't exist.

The climatic conditions expected on extrasolar moons will likely differ from those on extrasolar planets because moons are typically tidally locked to their planet. Thus, similar to the Earth’s moon, one hemisphere permanently faces the planet. Beyond that moons have two sources of light — that from the star and the planet they orbit — and are subject to eclipses that could significantly alter their climates, reducing stellar illumination. „An observer standing on the surface of such an exomoon would experience day and night in a totally different way than we do on Earth.” explained Heller. “For instance stellar eclipses could lead to sudden total darkness at noon.”

Heller and Barnes also identified tidal heating as a criterion for exomoon habitability. This additional energy source is triggered by a moon’s distance to its host planet; the closer the moon, the stronger tidal heating. Moons that orbit their planet too closely will undergo strong tidal heating and thus a catastrophic runaway greenhouse effect that would boil away surface water and leave them forever uninhabitable.

They also devised a theoretical model to estimate the minimum distance a moon could be from its host planet and still allow habitability, which they call the "habitable edge."This concept will allow future astronomers to evaluate the habitability of extrasolar moons. "There is a habitable zone for exomoons, it's just a little different than the habitable zone for exoplanets," Barnes said.

The exquisite photometric precision of NASA’s Kepler space telescope now makes the detection of a Mars- to Earth-sized extrasolar moon possible, indeed imminent. Launched in 2009, the telescope enabled scientists to reveal thousands of new extrasolar planet candidates. Since 2012 the first dedicated “Hunt for Exomoons with Kepler” is under way.

Exomoon habitability constrained by illumination and tidal heating - René Heller, Rory Barnes Assessing Exomoon Habitability
Centauri Dreams | Paul Gilster | 2013 Jan 11
Attachments
Artist’s conception of two extrasolar moons orbiting <br />a giant gaseous planet. (Credits: R. Heller, AIP)
Artist’s conception of two extrasolar moons orbiting
a giant gaseous planet. (Credits: R. Heller, AIP)
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Moons as Big as Earth? Not Yet

Post by bystander » Sun Jan 13, 2013 2:17 am

Moons as Big as Earth? Not Yet
Science Shot | Ken Croswell | 2013 Jan 11

Can a moon be as large as Earth? If so, it might support life. Our solar system's biggest moon—Jupiter's Ganymede—is only 41% of Earth's diameter, but other solar systems could sport larger satellites (artist's conception shown). Now, as astronomers report in work submitted to The Astrophysical Journal, they've used data from NASA's Kepler spacecraft to study seven planet-hosting stars, finding no moons at all. For four of the planets, the data are sufficiently good to rule out moons as small as Earth. The result suggests that Earth-sized moons are rare, but the sample is tiny—and so the search for supermoons will continue.
The Hunt for Exomoons with Kepler (HEK): II. Analysis of Seven Viable Satellite-Hosting Planet Candidates - David M. Kipping et al
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: Kepler

Post by orin stepanek » Fri Jan 18, 2013 9:19 pm

Seems unusual that the confirmed planet count remains at 105! :shock: Could this count need to be updated? :?
Orin

Smile today; tomorrow's another day!

User avatar
mjimih
Science Officer
Posts: 244
Joined: Tue Nov 27, 2012 2:48 am
AKA: Mark
Location: Minnesota usa

Re: Kepler ... is injured and resting

Post by mjimih » Sat Jan 19, 2013 2:04 am

http://www.newscientist.com/blogs/short ... jured.html

NASA planet-hunter is injured and resting
I prefer to picture the spacecraft lounging at the shore of the cosmic ocean sipping a Mai Tai so that she'll be refreshed and rejuvenated for more discoveries," wrote Kepler co-investigator Natalie Batalha in an email.
Mark

BDanielMayfield
Don't bring me down
Posts: 2524
Joined: Thu Aug 02, 2012 11:24 am
AKA: Bruce
Location: East Idaho

Re: Kepler ... is injured and resting

Post by BDanielMayfield » Sun Jan 27, 2013 11:39 pm

mjimih wrote:http://www.newscientist.com/blogs/short ... jured.html

NASA planet-hunter is injured and resting
I prefer to picture the spacecraft lounging at the shore of the cosmic ocean sipping a Mai Tai so that she'll be refreshed and rejuvenated for more discoveries," wrote Kepler co-investigator Natalie Batalha in an email.
Mark
So today’s (Jan 27, 2013) the day when they try turning Kepler’s squeaky gyro-wheel back on. The newscientist article Mark linked to gave the impression that the Kepler people weren’t all that tense about this, but with no remaining backups … What a bummer if this is it for Kepler. I know it’s like Monday morning quarterbacking, but it seems strange in hindsight that they sent it up with only one extra control wheel. Doesn’t Hubble have several extra gyros? :( :o
Just as zero is not equal to infinity, everything coming from nothing is illogical.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: Kepler ... is injured and resting

Post by neufer » Mon Jan 28, 2013 4:05 am

Click to play embedded YouTube video.
BDanielMayfield wrote:
So today’s (Jan 27, 2013) the day when they try turning Kepler’s squeaky gyro-wheel back on. The newscientist article Mark linked to gave the impression that the Kepler people weren’t all that tense about this, but with no remaining backups … What a bummer if this is it for Kepler. I know it’s like Monday morning quarterbacking, but it seems strange in hindsight that they sent it up with only one extra control wheel. Doesn’t Hubble have several extra gyros? :( :o
Art Neuendorffer

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: Kepler

Post by orin stepanek » Mon Jan 28, 2013 2:30 pm

Thanks Art! I hope the wheel works on restart!
Orin

Smile today; tomorrow's another day!

saturno2
Commander
Posts: 755
Joined: Wed Jun 29, 2011 10:05 pm

Re: Kepler

Post by saturno2 » Tue Jan 29, 2013 12:04 am

It is much better to have patience and do not force the delicate machine
elements of Kepler

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: Kepler

Post by orin stepanek » Wed Jan 30, 2013 12:29 pm

Orin

Smile today; tomorrow's another day!

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

In space no one can hear you squeak!

Post by neufer » Wed Jan 30, 2013 3:28 pm

Art Neuendorffer

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: In space no one can hear you squeak!

Post by orin stepanek » Thu Jan 31, 2013 1:46 pm

neufer wrote:
orin stepanek wrote:
Kepler is back in business :D http://www.nasa.gov/mission_pages/keple ... 32901.html
The squeaky wheel gets the grease.
8-) :D :yes: :thumb_up: :thumb_up:
Orin

Smile today; tomorrow's another day!

User avatar
Beyond
500 Gigaderps
Posts: 6889
Joined: Tue Aug 04, 2009 11:09 am
Location: BEYONDER LAND

Re: Kepler

Post by Beyond » Thu Jan 31, 2013 7:02 pm

I guess neufer, being self-proclaimed 'older-than-dirt', knows a lot about 'squeaky wheels' :?: :?:
To find the Truth, you must go Beyond.

User avatar
mjimih
Science Officer
Posts: 244
Joined: Tue Nov 27, 2012 2:48 am
AKA: Mark
Location: Minnesota usa

Re: Kepler

Post by mjimih » Thu Jan 31, 2013 8:12 pm

And now that Kepler is succumbing to entropy, there is new urgency for science from this awesome instrument. It is the first instrument to elevate our excitement for other worlds since the telescope itself imo. I hope it can find Earth-sized planets (with surface water), smack dab in the middle of habitable zones in orbits around Sun type stars. Probably a fairly small spinning target, farther out in medium orbits around average M stars, with light surface winds approx 15 mph, and almost always sunny n 78 degrees F at the beach.

How much longer estimated does Kepler need, in order to pull in enough data to finally confirm finding a few planets (almost) exactly like ours (that we know are out there now)? In other words, which will come first, discovery of an Earth twin or the gyros disabling the science mission?

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: Kepler

Post by neufer » Thu Jan 31, 2013 9:26 pm

mjimih wrote:
How much longer estimated does Kepler need, in order to pull in enough data to finally confirm finding a few planets (almost) exactly like ours (that we know are out there now)? In other words, which will come first, discovery of an Earth twin or the gyros disabling the science mission?
You are asking the wrong question.

Kepler just produces candidates; it doesn't confirm them or figure out their orbital distances.

That requires ground based telescopes with high dispersion spectrographs for Doppler analysis.

Kepler's list of possible earth like candidates is way ahead of ground based confirmations which will be taking place long after Kepler is defunct.
Art Neuendorffer

User avatar
mjimih
Science Officer
Posts: 244
Joined: Tue Nov 27, 2012 2:48 am
AKA: Mark
Location: Minnesota usa

Re: Kepler

Post by mjimih » Fri Feb 01, 2013 3:16 am

Kepler takes a long time to get data on planets with slower orbits right? Kepler would have seen Earth only 3 or 4 times by now. Planets like our little Earth are in a somewhat harder location in a solar system for an instrument like Kepler to see as often for the first years of it's mission right, taking at least a year to go around their star just once. Seems to me Kepler would have been designed for the long haul seeing as it has to wait for farther out planets to get around their stars a few more times, to help it discern their masses more precisely. Maybe three sets of three gyros, each with one back up, maybe next time. That would last it 30 years at least.

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Kepler Mission Discovers Tiny Planet System

Post by bystander » Thu Feb 21, 2013 1:36 am

Kepler Mission Discovers Tiny Planet System
NASA | JPL-Caltech | Ames | Kepler | 2013 Feb 20
NASA's Kepler mission scientists have discovered a new planetary system that is home to the smallest planet yet found around a star similar to our sun.

The planets are located in a system called Kepler-37, about 210 light-years from Earth in the constellation Lyra. The smallest planet, Kepler-37b, is slightly larger than our moon, measuring about one-third the size of Earth. It is smaller than Mercury, which made its detection a challenge.

The moon-size planet and its two companion planets were found by scientists with NASA's Kepler mission, which is designed to find Earth-sized planets in or near the "habitable zone," the region in a planetary system where liquid water might exist on the surface of an orbiting planet. However, while the star in Kepler-37 may be similar to our sun, the system appears quite unlike the solar system in which we live.

Astronomers think Kepler-37b does not have an atmosphere and cannot support life as we know it. The tiny planet almost certainly is rocky in composition. Kepler-37c, the closer neighboring planet, is slightly smaller than Venus, measuring almost three-quarters the size of Earth. Kepler-37d, the farther planet, is twice the size of Earth.

The first exoplanets found to orbit a normal star were giants. As technologies have advanced, smaller and smaller planets have been found, and Kepler has shown that even Earth-size exoplanets are common.

"Even Kepler can only detect such a tiny world around the brightest stars it observes," said Jack Lissauer, a planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "The fact we've discovered tiny Kepler-37b suggests such little planets are common, and more planetary wonders await as we continue to gather and analyze additional data."

Kepler-37's host star belongs to the same class as our sun, although it is slightly cooler and smaller. All three planets orbit the star at less than the distance Mercury is to the sun, suggesting they are very hot, inhospitable worlds. Kepler-37b orbits every 13 days at less than one-third Mercury's distance from the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would be hot enough to melt the zinc in a penny. Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively.

"We uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible," said Thomas Barclay, Kepler scientist at the Bay Area Environmental Research Institute in Sonoma, Calif., and lead author of the new study published in the journal Nature. "This discovery shows close-in planets can be smaller, as well as much larger, than planets orbiting our sun."

The research team used data from NASA's Kepler space telescope, which simultaneously and continuously measures the brightness of more than 150,000 stars every 30 minutes. When a planet candidate transits, or passes, in front of the star from the spacecraft's vantage point, a percentage of light from the star is blocked. This causes a dip in the brightness of the starlight that reveals the transiting planet's size relative to its star.

The size of the star must be known in order to measure the planet's size accurately. To learn more about the properties of the star Kepler-37, scientists examined sound waves generated by the boiling motion beneath the surface of the star. They probed the interior structure of Kepler-37's star just as geologists use seismic waves generated by earthquakes to probe the interior structure of Earth. The science is called asteroseismology.

The sound waves travel into the star and bring information back up to the surface. The waves cause oscillations that Kepler observes as a rapid flickering of the star's brightness. Like bells in a steeple, small stars ring at high tones while larger stars boom in lower tones. The barely discernible, high-frequency oscillations in the brightness of small stars are the most difficult to measure. This is why most objects previously subjected to asteroseismic analysis are larger than the sun.

With the very high precision of the Kepler instrument, astronomers have reached a new milestone. The star Kepler-37, with a radius just three-quarters of the sun, now is the smallest bell in the asteroseismology steeple. The radius of the star is known to three percent accuracy, which translates to exceptional accuracy in the planet's size.

Kepler helps find tiny planet beyond our solar system
Iowa State University | 2013 Feb 20

Moon-Sized Planet Orbits Sunlike Star
ScienceShot | Ken Crosswell | 2013 Feb 20

A sub-Mercury-sized exoplanet - Thomas Barclay et al
Smallest Exoplanet Yet Discovered by ‘Listening’ to a Sun-like Star
Universe Today | Nancy Atkinson | 2013 Feb 20

Astronomers Find the Tiniest Exoplanet Yet
Slate Blogs | Bad Astronomy | 2013 Feb 20

Mini-Mercury: Tiniest Exoplanet Discovered
Discovery News | Irene Klotz | 2013 Feb 20

How Does Tiny Kepler-37b Measure Up?
Discovery News | Ian O'Neill | 2013 Feb 20

Kepler Discovers a System of Tiny Planets
NASA Science News | Dr. Tony Phillips | 2013 Feb 20
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
mjimih
Science Officer
Posts: 244
Joined: Tue Nov 27, 2012 2:48 am
AKA: Mark
Location: Minnesota usa

Re: Kepler

Post by mjimih » Thu Feb 21, 2013 2:13 am

So Kepler can detect the presence of Earth sized planets (so far very) close to a sun-like star, but can it detect them in larger orbits more similar to ours (where life wouldn't be harassed as much by a hot neighbor)? How hard is it? I'm sure it will one day, but does Kepler need a lot more time to detect them or could it happen anytime?
Aliens will find Earth absolutely amazingly beautiful and fragile to behold. But if they get close enough, they'll see 7,000,000,000 of us and think "Uh oh, that's a lot for such a small planet. Wonder if we should help?"


User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

SAO: An Updated List of Potential Exoplanets

Post by bystander » Fri Mar 01, 2013 11:21 pm

An Updated List of Potential Exoplanets
Smithsonian Astrophysical Observatory
Weekly Science Update | 2013 Mar 01
There are currently 861 exoplanets (planets around other stars) according to the official exoplanet encyclopedia website. This list includes only the objects that have been confirmed as exoplanets; most of them have many of their physical parameters reasonably well determined, for example their masses and orbits. Many more objects have been spotted as potential, or “candidate,” exoplanets, but additional observations and analyses are needed to verify their reality as exoplanets.

How many? Writing in the latest issue of the Astrophysical Journal Supplement, a team of fourteen CfA astronomers, along with fifty-two of their colleagues, announced the figures. In the first sixteen months of operation, the Kepler spacecraft, which began operations in May, 2009, has found over 2300 candidate exoplanets in its observations (which examined over 190,000 stars). The new figure includes updates to earlier exoplanet candidate estimates and is based not only on additional observations but also on new data analysis techniques. Applied to the earlier datasets, these new techniques are better able to identify smaller candidates.

The huge new compilation significantly boosts the number of potential Earth-sized planets. More than 91% of the new candidates are smaller than Neptune; the number of candidates smaller than two Earth-radii jumped by 201%, with 624 new candidates. The fraction of stars hosting systems with more than one planet has also grown, from 17% to 20% of the total number of stars with planets. The new results are tantalizing in one other respect: the possibility that Earth-sized planets in their habitable zone (where water can remain liquid) will soon be discovered.

Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data - Natalie M. Batalha et al
<< Previous Science Update
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
mjimih
Science Officer
Posts: 244
Joined: Tue Nov 27, 2012 2:48 am
AKA: Mark
Location: Minnesota usa

Re: Kepler

Post by mjimih » Sat Mar 02, 2013 12:57 am

The new results are tantalizing in one other respect: the possibility that Earth-sized planets in their habitable zone (where water can remain liquid) will soon be discovered.
NOW yer talkin'!
Aliens will find Earth absolutely amazingly beautiful and fragile to behold. But if they get close enough, they'll see 7,000,000,000 of us and think "Uh oh, that's a lot for such a small planet. Wonder if we should help?"

User avatar
bystander
Apathetic Retiree
Posts: 21571
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Kepler Team Identifies Planet Impostors that are Binary Star

Post by bystander » Sat Mar 23, 2013 11:42 pm

Kepler Team Identifies Planet Impostors that are Binary Stars in Disguise
Universe Today | Dan Majaess | 2013 Mar 16
[attachment=0]redo_2.jpg[/attachment]
Observations by the Kepler satellite have advanced our knowledge of stars and their orbiting planets, yielding more than 100 confirmed planets and about 3,000 candidates. However, orbiting planets may not be the source for a fraction of those detections.

“There are many things in the sky that can produce transit-like signals that are not planets, and thus we must be sure to identify what really is a planet detected by Kepler,” Stephen Bryson told Universe Today. NASA Ames Research Center scientists Bryson and Jon Jenkins (also at the SETI Institute) are the lead authors on a new paper that aims to identify pseudo-planets detected by Kepler.

Small eclipses present in Kepler brightness measurements for a star (a lightcurve) may be indicative of an orbiting planet blocking light from its host star (see image right). However, under certain circumstances binary stars can mimic that signature. ...

Identification of Background False Positives from Kepler Data - Stephen T. Bryson et al
Attachments
Left, the lightcurve for a star featuring a transiting planet, whereby <br />the planet blocks a minute fraction of the host star’s light <br />(Image credit: Institute for Astronomy, University of Hawaii at Manoa).  <br /><br />Right, the combined light from a foreground bright star and a <br />fainter eclipsing binary system can mimic a transiting planet <br />(Image credit: chart and assembly, D. Majaess – <br />cropped stellar graphics from Collier Cameron 2012, Nature).
Left, the lightcurve for a star featuring a transiting planet, whereby
the planet blocks a minute fraction of the host star’s light
(Image credit: Institute for Astronomy, University of Hawaii at Manoa).

Right, the combined light from a foreground bright star and a
fainter eclipsing binary system can mimic a transiting planet
(Image credit: chart and assembly, D. Majaess –
cropped stellar graphics from Collier Cameron 2012, Nature).
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

Post Reply