Kepler Mission Options

[Guest_cassioli_*]

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So to determine how many AUs any planet is far from its star, I have just to divide its period by Earth period?

If that is correct, the most interesting planets are:
id KOI Rp Earth radius Kp Epoc Period (days) Teff (K) Logg (cm/s/s) R* (solar) Semimajor axis(UA)
8018547 902 0,83 8,30 15,8 169,808 83,90 4312 4,616000 0,940 0,229874
10666242 198 3,43 34,30 14,3 86,369 87,23 5538 4,629000 0,806 0,238995
6862328 865 0,63 6,30 15,1 155,237 119,02 5560 4,704000 1,232 0,326085
6867155 868 1,04 10,40 15,2 141,431 206,79 4118 4,517000 0,927 0,566545

Most far/slow planet is 10666242 (83,369 days, 0,24 UA = 36 mln km)

I can't understand how periods greater than Kepler mission length have been determined.

Edit:
wait, I forgot a root...
Ap[AU] = (Pp^2 / Pt^2 ) ^ 1/3

Is this correct?
Then 10666242 semimajor axis would be 0,385 AU?
(87,23^2 / 365 ^ 2) ^ 1/3

[Vultur]

Ah, thanks. That makes a lot more sense.

If that candidate is really a planet, it'd be pretty close to the habitable zone -- maybe within it, since that star's a bit smaller and cooler than the sun -- though it's Jupiter-size.

[hendric]

Cassioli,
That formula is only valid for the Solar System (or a very close to Sun mass star). The constant Sun mass cancels out on both sides of the equation, leaving the relationship between period and distance. To calculate, I think you want the gravitational formulas, available here:

http://en.wikipedia.org/wiki/Orbital_perio..._a_central_body

Given an estimate of the central mass based on stellar type, a distance can be calculated.

[remcook]

Actually, since Kepler is a photometer, it's quite capable of determining a star's brightness and colour, the first of which are how it's looking for planets.

Right, a photometer measures the amount of light. But to determine colour you need at least two wavelengths where you measure the light. From browsing the Kepler website and wikipedia, it seems they only measure the light throughout the entire 400-850 nm band and there is no spectral resolution. Hence no colour determination.

[akuo]

All the stars Kepler observes should be well known from previous sky surveys and other observations. After all they are relatively bright stars, all Kepler is adding is a huge amount of constant photometry for each. Therefore a lot of basic characteristics of the stars should be already known beforehand. Additionally I am sure Kepler scientists will request additional observations of candidate star systems.

[Greg Hullender]

I think the Kepler site itself has a nice explanation of what they do.

http://www.kepler.arc.nasa.gov/Science/cha...ticsOfTransits/

--Greg

[Habitable Zoner]

The latest update has arrived here. Biggest news: there will be a discovery announcement in early November. Next biggest news: Kepler 9d, the hot superearth, will soon be upgraded from "potential" to "planet."

[Habitable Zoner]

Kepler insider, "Dr. Jason Steffen of Fermi National Laboratory in Batavia, Ill., will shed light on NASA's recent ventures in the stars during the Harry Nelson Endowed Lecture of Astronomy on Thursday, October 21, at 7:30 p.m." at Augustana College in Rock Island, IL. For more information, see here.

I'm looking forward to early November. Reason 1: The US midterm elections will be over, so no more political attack ads on TV. Reason 2: Anticipating a Kepler discovery announcement.

[Syrinx]

It was what, 6 months ago that somebody on the team remarked that NASA HQ had asked them for a press release in November, to be followed by another one a few weeks later. Followed by the big AAS meeting in Seattle in February, which is as noted by Bill Borucki is when they'd have something real to discuss.

I'd expect the press release in November to contain a few more confirmed planets, which is certainly exciting in its own right.

[Habitable Zoner]

The Kepler Asteroseismic Science Consortium (KASC) at Aarhus University in Denmark will hold a media teleconference on Tuesday, Oct. 26, at 11 a.m. EDT to discuss the latest discoveries about stars and their structures using data from NASA's Kepler spacecraft." (full release)

Probably not an announcement of planets based on the wording, but probably a significant announcement nevertheless...

[Habitable Zoner]

The talk turned out to be a nice summary of how Kepler is contributing to the field of asteroseismology. Slides are here.

[Syrinx]

I'm reading through "The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters" authored by Howard and Marcy from UC-Berkeley and a bunch of other people. The official release is behind a paywall:

http://www.sciencemag.org/cgi/content/abstract/330/6004/653

but if you search the title in everybody's favorite search engine you can find it at the Keck web site (I won't paste the link without permission).

Regarding Kepler:

The Kepler mission (31) is currently surveying 156,000 faint stars for transiting planets as
small as the Earth. Our power law model predicts that Kepler will detect a bounty of close-in
small planets: an occurrence rate of 22% for P < 50 days and M sin i = 1–8 MEarth, corresponding
to 1–2 Earth-radii assuming terrestrial, Earth-like density (5.5 kg m^-3). When the
mission is complete, we estimate (see SOM) that Kepler will have detected the transits of 120–
260 of these plausibly terrestrial worlds orbiting the ~10^4 G and K dwarfs brighter than 13th
magnitude (32, 33).

To estimate the number of planets detected by the Kepler mission with P < 50 d and radii
of 1–2 Earth-radii (implying masses of 1–8 MEarth assuming Earth density of 5.5 kg m^-3),

[...big snip...]

we find that 1.2–2.6% of stars (68% confidence interval) will harbor a [Kepler-detectable] transiting planet with the specified parameters.

[remcook]

It's also available here: http://arxiv.org/abs/1011.0143

[Syrinx]

Nov. 17 Astronomy Lecture Explores Catching Shadows: Kepler's Search for New Worlds
Wednesday, Nov. 17 at 7 p.m., in the Smithwick Theatre at Foothill College in Los Altos Hills

As part of the 12th annual Silicon Valley Astronomy Lecture Series, Astronomer Natalie Batalha from San Jose State University and the Kepler Mission, will present Catching Shadows: Kepler's Search for New Worlds.

Humanity's quest to learn about the existence of other worlds like our own has made a huge step forward with the launch of NASA's Kepler spacecraft in March 2009. The mission is designed to survey a slice of the Milky Way Galaxy to identify planets orbiting other stars. Kepler has the advantage that it can find planets as small as Earth in or near the habitable zone of each star. It will help us determine if such planets are abundant in our galaxy. Dr. Batalha will describe the techniques used by the Kepler team to identify Earth-size planets and share some of the mission discoveries to date.

http://www.foothill.fhda.edu/ast/news.htm#Anchor1

[Habitable Zoner]

Interesting quote from Geoffrey Marcy in a recent space.com article:

"Many of the candidates Kepler discovered are now getting verified with radial velocity confirmations. 'On Feb. 1, we'll announce all of them — a huge avalanche of exoplanet candidates,' Marcy said."