Kepler News and Results

First result of RV followup on the list of Kepler transiting planet candidates: KOI-428b.

Preprint (pdf)

Nice way to close this old year. Happy new years everybody and cheers!

Interesting table

http://arxiv.org/abs/1101.0463


In general, it is clear that for HAPRS (or HIRES) for stars with V=12 and v<2 km/s is achieved accuracy of stellar activity 1 hour exposure.

Respectively,
V=11 T=1/2.5=0.4 hour exposure or 24 minutes;
V=10 T=1/2.5*2.5=0.16 hour exposure or 10 minutes;
V=9 T=1/2.5*2.5*2.5=0.064 hour exposure or 4 minutes;
V=8 T=1/2.5*2.5*2.5*2.5=0.0256 hour exposure or 1.5 minutes;

And now the star sample Kepler


Yellow - super-Earths (16680 stars)
Orange color - Neptune (16680+30304 stars)
Red - only giants and brown dwarfs

Assume that the slowly rotating stars (v<2 km/s) only one-third:

V=<12 16067/3=5356 slowly rotating stars
V=<11 5492/3=1830 slowly rotating stars
V=<10 1793/3=597 slowly rotating stars
V=<9 605/3=201 slowly rotating stars
V=<8 199/3=66 slowly rotating stars

So I think there are no big problems to confirm the hot transit earth with K=1-2 m/s (and mass 1-2 Earth masses) around star with V=8-9 mag.

The more so recent discoveries of California group confirm the high frequency of such planets.
http://www.jpl.nasa.gov/images/universe/exo20101028/exo20101028-a-640.jpg

Unfortunately HARPS is not in a good location to observe stars in the Kepler field...

Lazarus wrote:

Unfortunately HARPS is not in a good location to observe stars in the Kepler field...

HARPS and Keck-HIRES similar in accuracy. And even more due to the large mirror at the HIRES shorter exposure.

For example
http://arxiv.org/abs/1009.2597
CoRoT-11 V=12.9

Spectrograph, the accuracy in meters per second, the exposure time (seconds)
SOPHIE-HE Mode 206-218 1402-1607
HARPS-EGGS Mode 67-115 1800-2700
HARPS-Standard Mode 83-149 3300-3600
COUDE-TLS 174-175 2×1800
HIRES 50-142 900-1200

As seen in HIRES and the highest accuracy, and the shortest exposure.

http://files.aas.org/aas217/aas217_abstracts.pdf

On page 218:

"The NASA Kepler Mission has discovered over 700 candidate planets, with most
having diameters less than 5 times that of Earth and some as small as that of Earth.
One planet has a radius, mass, and density in a new domain having
no counterpart in our Solar System, opening a new chapter in planetary science"

Welcome Kepler 9d - sort of... almost the smallest planet around another star

Torres et al. 2011 ApJ 727 24

Another Kepler discovery: KOI-126, the first eclipsing triple system.

Dynamics of Cats has more details: apparently it is an F star with a close pair of M dwarfs in orbit.

For those lucky enough to have access to papers in Science, the KOI-126 paper is here.

NASA To Announce New Planetary Discoveries
WASHINGTON -- NASA will host a news briefing at 1 p.m. EST, Wednesday, Feb. 2, to announce the Kepler mission's latest findings about planets outside our solar system. The briefing will be held in the NASA Headquarters auditorium at 300 E St S.W. in Washington and carried live on NASA Television and the agency's website at http://www.nasa.gov/ntv.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the "habitable zone," the region in a planetary system where liquid water can exist on the surface of the orbiting planet. Although additional observations will be needed over time to achieve that milestone, Kepler is detecting planets and planet candidates with a wide range of sizes and orbital distances to help us better understand our place in the galaxy.

The news conference will follow the scheduled release of Kepler mission science data on Feb. 1. The data release will update the number of planet candidates and is based on observations conducted between May 2 and Sept. 17, 2009.

Participants are:
-- Douglas Hudgins, Kepler program scientist, NASA Headquarters, Washington
-- William Borucki, Kepler Science principal investigator, NASA's Ames Research Center, Moffett Field, Calif.
-- Jack Lissauer, Kepler co-investigator and planetary scientist, Ames
-- Debra Fischer, professor of Astronomy, Yale University, New Haven, Conn.

Wonder if/when KOI-428b will get a Kepler-# designation...

Lazarus wrote:

For those lucky enough to have access to papers in Science, the KOI-126 paper is here.

Here it's paper about this system: KOI-126: A Triply Eclipsing Hierarchical Triple with Two Low-Mass Stars.

http://www.sciencemag.org/content/suppl/2011/01/10/science.1201274.DC1/Carter_SOM.pdf

http://arxiv.org/abs/1101.5630

Quote :

ON THE LOW FALSE POSITIVE PROBABILITIES OF KEPLER PLANET CANDIDATES
Timothy D. Morton1,John Asher Johnson1,2
Draft version February 1, 2011
ABSTRACT
We present a framework to conservatively estimate the probability that any particular planet-like transit signal observed by the Kepler mission is in fact a planet, prior to any ground-based follow-up eorts. We use Monte Carlo methods based on stellar population synthesis and Galactic structure models, and we provide empirical analytic fits to our results that may be applied to the as-yetuncon formed Kepler candidates. We and that the false positive probability for candidates that pass preliminary Kepler vetting procedures is generally <10% and often <5%, assuming a 20% occurrence rate of close-in planets in the mass range 0.5 MEarth < Mp < 10 MJup.

I think I've found out what the announcement is going to be. If so, it is another genuinely interesting case. Seems to be quite revealing about the Kepler confirmation strategy, after the first five (hot Jupiters/hot Neptunes, relatively easy to confirm for early announcement), we are getting a set of harder-to-confirm systems. Looks like they are going for the high-payoff systems rather than churning out confirmations of hot massive planets, leaving the majority of the latter for the public data releases.

So around 90% of candidates are true planet -great .I am waiting unpatiently for next kepler release in this mounth.Besides kepler 10 b is not interested so much because most light elements of the planet is gone and remained only heavy stuff.Candidate 10c if confirmed is much more interested because 0.24 AU from host star is enough to avoid any atmosphere loss and that is why we know true density and composition

Most of the kepler planets have small radius and very likely(mention about low densities) low mass and confirmation planets even little further from host star can be very difficult

Does this means that we just added between 500 and 650 new planets in the system. Or do we publish the Kepler candidate with a probability of 90%

90% isn't significant enough to claim a confirmation. The planet candidates will require RV confirmation.

Confirmation of 500 planets using RV measurement is very challenging especially for the small planets, requiring an 8M telescope. There is not enought Telescope time available for this. There must be a less expensive way to increase each planet probability and bring it to the 98% level.
Over the next 2 years Kepler should come up with another set of 500 planet candidates at 90%.
This high hit rate will change the planet hunting game In the near future, Astronomers might abandon their random RV work and only concentrate at the Kepler candidates that look promissing for a new discovery.
Now we need another 2 or 3 Kepler to get this number to 3 ot 5 thousand

Roland Borrely wrote:

Over the next 2 years Kepler should come up with another set of 500 planet candidates at 90%.

Why is that? They aren't changing star fields.

Roland Borrely wrote:

Astronomers might abandon their random RV work and only concentrate at the Kepler candidates that look promissing for a new discovery.

That's already what's going on. RV measurements are done strategically to use fewer measurements for each planet candidate. Kepler candidates are weeded out by preliminary observations with deep imaging to look for blends, etc.

T. Morton conclude his just published article, pointed by Borislav that almost all Jupiter diameter transits are real planets and that Kepler candidates around stars of M 11,12 the probability is close to 98%. For M 13, 3 times worst and M14, 10 times.
But the error rate can be significantly reduced by a single high resolution picture that would reduce the area where a double transiting stars would be.
This does not give a 100% but will get close to the goal
[url=http://arxiv.org/abs/1101.5630]

Kepler in Safe Mode again...

Some resources here.
http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=98

Including an updated list of candidates.

An oklo.org blog entry on the subject.
http://oklo.org/2011/02/02/a-quarter-million-dollar-world/

One of the candidates is particularly interesting.