Kepler News and Results (Thread 2)

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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 30th November 2015, 10:01 pm

http://arxiv.org/abs/1511.09097

The Kepler-454 System: A Small, Not-rocky Inner Planet, a Jovian World, and a Distant Companion

Kepler-454 (KOI-273) is a relatively bright (V = 11.69 mag), Sun-like starthat hosts a transiting planet candidate in a 10.6 d orbit. From spectroscopy, we estimate the stellar temperature to be 5687 +/- 50 K, its metallicity to be [m/H] = 0.32 +/- 0.08, and the projected rotational velocity to be v sin i <2.4 km s-1. We combine these values with a study of the asteroseismic frequencies from short cadence Kepler data to estimate the stellar mass to be 1.028+0:04-0:03 M_Sun, the radius to be 1.066 +/- 0.012 R_Sun and the age to be 5.25+1:41-1:39 Gyr. We estimate the radius of the 10.6 d planet as 2.37 +/- 0.13 R_Earth. Using 63 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 36 observations made with the HIRES spectrograph at Keck Observatory, we measure the mass of this planet to be 6.8 +/- 1.4M_Earth. We also detect two additional non-transiting companions, a planet with a minimum mass of 4.46 +/- 0.12 M_J in a nearly circular 524 d orbit and a massive companion with a period> 10 years and mass >12.1M_J . The twelve exoplanets with radii <2.7 R_Earth and precise mass measurements appear to fall into two populations, with those <1.6 R_Earth following an Earth-like composition curve and larger planets requiring a significant fraction of volatiles. With a density of 2.76 +/- 0.73 g cm-3, Kepler-454b lies near the mass transition between these two populations and requires the presence of volatiles and/or H/He gas
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 2nd December 2015, 2:21 pm

Edasich wrote:Mass constrains for several Kepler giant planets from SOPHIE

SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period

« …Half of Kepler’s giant exoplanet candidates are false positives… »
(A. Santerne)


http://www.iastro.pt/news/news.html?ID=29
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 7th December 2015, 10:36 pm

http://arxiv.org/abs/1512.02003

Robust TTV Mass Measurements: Ten Kepler Exoplanets between 3 and 8 Earth Masses with Diverse Densities and Incident Fluxes

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Re: Kepler News and Results (Thread 2)

Post by Sirius_Alpha on 8th December 2015, 9:57 pm

Some new long-period planets, some of which have only one transit observation, and they constrain the orbital period based on the transit light curve shape and host star properties. One of these things has a maximum likelihood orbital period of ~240 years.

Planet Hunters. VIII. Characterization of 41 Long-Period Exoplanet Candidates from Kepler Archival Data
http://arxiv.org/abs/1512.02559

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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 14th December 2015, 3:16 pm

Orbit determination for the Kepler-444 A-BC orbit suggests the BC pair gets as close as 5 AU (!) to the primary star at periastron.

Dupuy et al. "Orbital Architectures of Planet-Hosting Binaries: I. Forming Five Small Planets in the Truncated Disk of Kepler-444A"
http://arxiv.org/abs/1512.03428
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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 15th December 2015, 6:07 pm

Revisiting the Kepler M dwarfs.

Gaidos et al. "They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets"
http://arxiv.org/abs/1512.04437
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 21st December 2015, 9:59 pm

http://arxiv.org/abs/1512.06149

Planetary Candidates Observed by Kepler.
VII. The First Fully Uniform Catalog Based on The Entire 48 Month Dataset (Q1-Q17 DR24)


We present the seventh Kepler planet candidate catalog, which is the first to be based on the entire, uniformly processed, 48 month Kepler dataset. This is the first fully automated catalog, employing robotic vetting procedures to uniformly evaluate every periodic signal detected by the Q1-Q17 Data Release 24 (DR24) Kepler pipeline. While we prioritize uniform vetting over the absolute correctness of individual objects, we find that our robotic vetting is overall comparable to, and in most cases is superior to, the human vetting procedures employed by past catalogs. This catalog is the first to utilize artificial transit injection to evaluate the performance of our vetting procedures and quantify potential biases, which are essential for accurate computation of planetary occurrence rates. With respect to the cumulative Kepler Object of Interest (KOI) catalog, we designate 1,478 new KOIs, of which 402 are dispositioned as planet candidates (PCs). Also, 237 KOIs dispositioned as false positives (FPs) in previous Kepler catalogs have their disposition changed to PC and 118 PCs have their disposition changed to FP. This brings the total number of known KOIs to 8,826 and planet candidates to 4,696. We compare the Q1-Q17 DR24 KOI catalog to previous KOI catalogs, as well as ancillary Kepler catalogs, finding good agreement between them. We highlight new PCs that are both potentially rocky and potentially in the habitable zone of their host stars, many of which orbit solar-type stars. This work represents significant progress in accurately determining the fraction of Earth-size planets in the habitable zone of Sun-like stars. The full catalog is publicly available at the NASA Exoplanet Archive.

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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 31st December 2015, 2:45 pm

http://aas.org/meetings/aas227

Abstract of the AAS 227th meeting, next week :

138.13 – The mass of the super-Earth orbiting the
brightest Kepler planet hosting star
HD 179070, aka Kepler-21, is a V = 8.25 oscillating F6IV star and the
brightest exoplanet host discovered by Kepler. An early analysis of
the Q0 – Q5 Kepler light curves by Howell et al. (2012) revealed
transits of a planetary companion, Kepler-21b, with a radius of 1.6
R_Earth and an orbital period of 2.7857 days. However, they could
not determine the mass of the planet from the initial radial velocity
observations with Keck-HIRES, and were only able to impose a 2s
upper limit of about 10 M_Earth. Here we present 82 new radial
velocity observations of this system obtained with the HARPS-N
spectrograph
. We detect the Doppler shift signal of Kepler-21b at the
3.6s level, and measure a planetary mass of 5.9 ± 1.6 M_Earth. We
also update the radius of the planet to 1.65 ± 0.08 R_Earth, using the
now available Kepler Q0 – Q17 photometry for this target. The mass
of Kepler-21b appears to fall on the apparent dividing line between
super-Earths that have lost all the material in their outer layers and
those that have retained a significant amount of volatiles. Based on
our results Kepler-21b belongs to the first group.
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Re: Kepler News and Results (Thread 2)

Post by tommi59 on 31st December 2015, 3:16 pm

No surprise at all is rocky I did not expect something else.We should wait until we measure masses of planets between 1.4-1.7 earth radius with low incident flux or under 750K currently we have none only k-57 b seems to be rocky but in need to check for stellar companion
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 5th January 2016, 5:49 pm

http://exoplanetarchive.ipac.caltech.edu/docs/exonews_archive.html

New Planets: We're ringing in the new year with 12 more planets, bringing the confirmed planet count to 1,930. The new planets are HD 32963 b, KIC 3558849 b (Kepler-455 b), KIC 5951458 b (Kepler-456 b), KIC 8540376 b & c (Kepler-457 b & c), KIC 9663113 b (Kepler-458 b), KIC 10525077 b (Kepler-459 b), KIC 5437945 b (Kepler-460 b), K2-25 b, and Wolf 1061 b, c & d. View their individual Overview pages by clicking on their names, or view their aggregate data in the Confirmed Planets table.
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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 13th January 2016, 12:41 pm

The KIC 7177553 system is an SB4 system containing an eclipsing binary and a second binary pair. The eclipse timing of this system suggests the presence of a ~5 Jupiter mass planet in an eccentric orbit around the eclipsing pair.

Lehmann et al. "KIC 7177553: a quadruple system of two close binaries"
http://arxiv.org/abs/1601.02926

The details of the planetary companion can be found in an earlier paper (see table 6):

Borkovits et al. "A Comprehensive Study of the Kepler Triples via Eclipse Timing"
http://arxiv.org/abs/1510.08272
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Re: Kepler News and Results (Thread 2)

Post by Shellface on 14th January 2016, 1:05 pm

Ah, I was wondering if anybody was going to notice this. The paper has a rather modest title.

From their previous value for m(c)/m(a+b+c) = 0.0028 ± 0.0003, I get a mass function for the perturber of (0.00546 ± 0.00061)*m(a), m(a) being the mass of the primary star. For their new value for m(a) of 1.043 ± 0.014 Msol, I get a mass for the perturber of 5.97 ± 0.74 Mjup. I believe that's m(sini).

It's rather surprising that this system is composed of four near-analogous stars, which form hierarchical pairs that both have similar orbits (even their periapsides are near-aligned). I doubt Kozai oscillations could have much influence considering the relative separations of the binaries, but this would otherwise have to be an exceptionally unlikely happenstance.

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Re: Kepler News and Results (Thread 2)

Post by tommi59 on 25th January 2016, 9:32 am

Transit timing variations (TTVs) of Kepler-10c indicate the likely presence of a third planet in the system, KOI-72.X. The TTVs and RVs are consistent with KOI-72.X having an orbital period of 24, 71, 82, or 101 days, and a mass from 1-7 M⊕.
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Re: Kepler News and Results (Thread 2)

Post by tommi59 on 25th January 2016, 9:50 am

Kepler-47: A Three-Planet Circumbinary System
Kepler-47 is the most interesting of the known circumbinary planets. In the discovery paper by Orosz et al. (2012) two planets were detected, with periods of 49.5 and 303 days around the 7.5-day binary. In addition, a single "orphan" transit of a possible third planet was noticed. Since then, five additional transits by this planet candidate have been uncovered, leading to the unambiguous confirmation of a third transiting planet in the system. The planet has a period of 187 days, and orbits in between the previously detected planets. It lies on the inner edge of the optimistic habitable zone, while its outer sibling falls within the conservative habitable zone. The orbit of this new planet is precessing, causing its transits to become significantly deeper over the span of the Kepler observations. Although the planets are not massive enough to measurably perturb the binary, they are sufficiently massive to interact with each other and cause mild transit timing variations (TTVs). This enables our photodynamical model to estimate their masses. We find that all three planets have very low-density and are on remarkably co-planar orbits: all 4 orbits (the binary and three planets) are within ~2 degrees of one another. Thus the Kepler-47 system puts interesting constraints on circumbinary planet formation and migration scenarios.
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Re: Kepler News and Results (Thread 2)

Post by tommi59 on 25th January 2016, 9:52 am

KIC-5473556: the Largest and Longest-period Kepler Transiting Circumbinary Planet
We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of short-period CBPs orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet in the KIC-5473556 system has a very long orbital period (~1100 days) and was at conjunction only twice during the Kepler mission -- making it the longest-period transiting CBP at the time of writing. With a radius of nearly 12 REarth, it is also the largest such planet to date. It produced three transits in the light curve of KIC 5473556, one of them during a syzygy. The planet revolves around an ~11-day Eclipsing Binary consisting of two Solar-mass stars on a slightly inclined to the line of sight, mildly eccentric (ebin = 0.16) orbit. The CBP measurably perturbs the times of the stellar eclipses, allowing us to constrain its mass well. Here we present our spectroscopic and photometric observations of the target, discuss our analysis of the system, and outline the theoretical implications of our discovery.

http://ciera.northwestern.edu/Hawaii2015/ExSS_3_2015_abstracts.pdf
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 25th January 2016, 10:53 am

KIC-5473556 is KOI-2939

On arXiv : http://arxiv.org/abs/1512.00189
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Re: Kepler News and Results (Thread 2)

Post by tommi59 on 25th January 2016, 11:31 am

Right led zep I have missed this.
Kepler 10 c however contains some volatiles or water is not pure rock / iron
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 25th January 2016, 11:56 am

Have you a link for the third planet in K-47 system ?
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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 25th January 2016, 2:36 pm

Led_Zep wrote:Have you a link for the third planet in K-47 system ?
They're all in the abstracts booklet tommi59 linked in this post

As far as I'm aware, no discovery paper has yet been released, although it has been cited as "forthcoming" or "in prep" a couple of times.
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 26th February 2016, 2:18 pm

http://arxiv.org/abs/1602.07848

Transiting Planet Candidates Beyond the Snow Line Detected by Visual Inspection of 7557 Kepler Objects of Interest

We visually inspected the light curves of 7557 Kepler Objects of Interest (KOIs) to search for single transit events (STEs) possibly due to long-period giant planets. We identified 28 STEs in 24 KOIs, among which 14 events are newly reported in this paper. We estimate the radius and orbital period of the objects causing STEs by fitting the STE light curves simultaneously with the transits of the other planets in the system or with the prior information on the host star density. As a result, we found that STEs in seven of those systems are consistent with Neptune- to Jupiter-sized objects of orbital periods ranging from a few to ∼ 20yr. We also estimate that ≳20% of the compact multi-transiting systems host cool giant planets with periods ≳3yr on the basis of their occurrence in the KOIs with multiple candidates, assuming the small mutual inclination between inner and outer planetary orbits.
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Re: Kepler News and Results (Thread 2)

Post by PlutonianEmpire on 22nd March 2016, 4:51 pm

In 2011, Kepler caught a supernova.

https://www.nasa.gov/feature/ames/Kepler/caught-for-the-first-time-the-early-flash-of-an-exploding-star/

http://www.space.com/32337-first-supernova-shock-wave-imaged-by-kepler.html

For the first time, scientists have seen the shock wave emanating from an exploding star in visible light.

Using NASA's planet-hunting Kepler Space Telescope, researchers saw the shock wave coming from a massive star explosion (a supernova) that came into Kepler's view in 2011. The star that ended its life as a supernova is named KSN 2011d, which is nearly 500 times the diameter of the sun, and located about 1.2 billion light-years away.

The shock breakout lasted only about 20 minutes, so Kepler's ability to catch a glimpse of this event is "an investigative milestone for astronomers," NASA said. At the time Kepler observed the explosion, the telescope was gazing continuously at a point in the Cygnus constellation, looking for extrasolar planets. The shock wave observation will give investigators more information into how these shock waves are formed from stellar explosions.

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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 22nd March 2016, 5:38 pm

Good spot, saw the headlines for this one but didn't realise it was a Kepler result.
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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 24th April 2016, 11:53 am

https://aas.org/meetings/aas228

Abstract from the 228th meeting of AAS in San Diego, 12-16 june 2016

A new circumbinary planet !!

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Re: Kepler News and Results (Thread 2)

Post by Led_Zep on 4th May 2016, 3:38 pm

http://www.nasa.gov/press-release/nasa-to-announce-latest-kepler-discoveries-during-media-teleconference

NASA will host a news teleconference at 1 p.m. EDT Tuesday, May 10 to announce the latest discoveries made by its planet-hunting mission, the Kepler Space Telescope

the record of 715 new planets confirmed could be beaten !!
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Re: Kepler News and Results (Thread 2)

Post by Lazarus on 5th May 2016, 2:40 am

According to NASA Watch, it may be about the detection of companions to Kepler exoplanet host stars.

Baranec et al. (2016) "Robo-AO Kepler Planetary Candidate Survey II: Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars"
http://arxiv.org/abs/1604.08604
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Re: Kepler News and Results (Thread 2)

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