The Radius Distribution of Planets Around Cool Stars

Morton, Timothy; Swift, Jonathan J.

doi:10.1088/0004-637x/791/1/10

Cited by 156 publications

(169 citation statements)

References 64 publications

Supporting

Mentioning

152

Contrasting

Order By: Relevance

“…Lastly, some evidence of transittiming variations was found by Ford et al (2011), but it was noted that the short duration likely affected the transit times so the variations may not be significant. The depth difference measured in our photometry (Table 4) combined with the high FPP computed by our group (and by Morton &Swift 2014 andSwift et al 2015) from the Kepler photometry suggests that KOI 531.01 is indeed a false positive. Our FPP calculations specifically suggest that KOI 531.01 is itself an EB (rather than being a hierarchical system or a blend with a background eclipsing system).…”

Section: Koi 53101supporting

confidence: 61%

“…While commonly treated as a planet, Morton & Swift (2014) notably find KOI 531.01 to have a calculated false positive probability of 99%. A more recent calculation using all available quarters of Kepler data yielded a false positive probability of 48% (Swift et al 2015), which is still high but not conclusive evidence of a false positive nature.…”

Section: Koi 53101mentioning

confidence: 99%

“…Notably, KOI 225.01 is currently listed in the archive as a planet candidate, but it is clearly a false positive based on the significant wavelength-dependent transit depth (Paper II). KOI 531.01 is also listed as a planet candidate, though it has a false positive probability > ∼ 50% (Morton & Swift 2014;Swift et al 2015). These distributions clearly emphasize the continued prevalence of eclipsing binaries (and correspondingly, false positives) at the shortest orbital periods, as discussed in further detail in Paper II.…”

mentioning

confidence: 99%

See 2 more Smart Citations

VettingKeplerplanet candidates in the sub-Jovian desert with multiband photometry

Colón

Morehead

2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We present new multi-band transit photometry of three small (R p < ∼ 6 R ⊕ ), shortperiod (P < ∼ 6 days) Kepler planet candidates acquired with the Gran Telescopio Canarias. These observations supplement the results presented in Colón & Ford (2011) and Colón et al. (2012), where we used multicolor transit photometry of five Kepler planet candidates to search for wavelength-dependent transit depths and either validate planet candidates or identify eclipsing binary false positives within our sample. In those previous studies, we provided evidence that three targets were false positives and two targets were planets. Here, we present observations that provide evidence supporting a planetary nature for KOI 439.01 and KOI 732.01, and we find that KOI 531.01, a 6 R ⊕ planet candidate around an M dwarf, is likely a false positive. We also present a discussion of the purported "sub-Jovian desert" in the orbital period-planet radius plane, which cannot be easily explained by observational bias. Both KOI 439.01 and KOI 732.01 are likely planets located within the so-called desert and should be investigated with further follow-up observations. As only ∼30 of the ∼3600 currently active Kepler planet candidates are located within the sub-Jovian desert, it will be interesting to see if these candidates also survive the vetting process and fill in the gap in the period-radius plane. Confirming planets in this regime will be important for understanding planetary migration and evolution processes, and we urge additional follow-up observations of these planet candidates to confirm their nature.

show abstract

Section: Koi 53101supporting

confidence: 61%

Section: Koi 53101mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

VettingKeplerplanet candidates in the sub-Jovian desert with multiband photometry

Colón

Morehead

2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…• 3 R ⊕ R p 7 R ⊕ : Planets in this size range are less dense than water, implying voluminous H/He atmospheres (Wu & Lithwick 2013). The occurrence rate plummets between 2 and 3 R ⊕ (Petigura et al 2013b;Morton & Swift 2014), so this class is much rarer than the first two. Few planets in this class have been found around low-mass stars (Wu & Lithwick 2013).…”

Section: The Diverse Physical Properties Of Kepler Planetsmentioning

confidence: 99%

Advances in exoplanet science from Kepler

Lissauer

Dawson

Tremaine

2014

Nature

View full text Add to dashboard Cite

Numerous telescopes and techniques have been used to find and study extrasolar planets, but none has been more successful than NASA's Kepler Space Telescope. Kepler has discovered the majority of known exoplanets, the smallest planets to orbit normal stars, and the worlds most likely to be similar to our home planet. Most importantly, Kepler has provided our first look at typical characteristics of planets and planetary systems for planets with sizes as small as and orbits as large as those of the Earth.Kepler is a 0.95 m aperture space telescope launched by NASA in 2009Koch et al. 2010). Kepler identifies those exoplanets whose orbits happen to appear edge-on by searching for periodic dips caused by planetary transits (partial eclipses) of the stellar discs. Above Earth's atmosphere, and in an Earth-trailing heliocentric orbit away from the glare and thermal variations of low Earth orbit, Kepler monitored the brightness of more than 10 5 stars at 30-minute cadence for four years. Kepler's unique asset is an unprecedented photometric precision of ∼ 30 parts per million (ppm) for 12th magnitude stars with data binned in 6.5 hour intervals (Gilliland et al. 2011). This time interval is used as a benchmark because the Earth takes 13 hours to transit the Sun as viewed by a distant observer in the ecliptic plane, and observers slightly away from the ecliptic view a transit of shorter duration. Such high-precision measurements are only possible in space, where stars do not twinkle, and are required to search for Earth-like worlds because the transit of such a planet across the disc of a Sun-like star blocks only 80 ppm of the stellar flux. For comparison, the transit of a Jupiter-size planet across a similar star blocks 1% of the flux, and this dip is straightforward to detect using ground-based telescopes.Transits of ∼ 3600 planet candidates, the vast majority of which represent true exoplanets as described below, have been identified in the first three years of Kepler data ( Figure 1). The discovery of these worlds, most of which have orbital periods (local "years") shorter than a few Earth months, has greatly expanded the zoo of known exoplanet types. Kepler planets have radii, R p , intermediate between those of Earth and Neptune (1 -3.8 R ⊕ , where R ⊕ = 6371 km is the Earth's radius); planets in this size range are missing from our Solar System. These planets have a wide range of densities Lissauer et al. 2011a;Doyle et al. 2011;Carter et al. 2012;Jontof-Hutter et al. 2014;Marcy et al. 2014), probably because they have atmospheres with a wide range of properties. Nonetheless, theoretical models of their interiors (e.g., Fortney et al. 2007) imply that all of the planets in this class are "gas-poor", that is, less than half -in most cases far less -of their mass consists of hydrogen and helium (H/He). In contrast, H/He make up more than 98% of our Sun's mass as well as substantial majorities of the masses of Jupiter, Saturn, and almost all known giant exoplanets with R p > 9 R ⊕ .Kepler's primary mission is to c...

show abstract

“…Kepler's large exoplanet sample has led to statistical analyses of the frequency of exoplanets around solar mass stars (Howard et al 2012;Youdin 2011;Fressin et al 2013), around cool stars (Swift et al 2013;Morton & Swift 2014), and in their stars' habitable zones (Dressing & Charbonneau 2013;Petigura et al 2013;Foreman-Mackey et al 2014). Kepler's scientific contributions extend beyond exoplanets to fields ranging from asteroseismology (Chaplin et al 2011) to active galactic nuclei variability (Mushotzky et al 2011).…”

Section: Introductionmentioning

confidence: 99%

A Technique for Extracting Highly Precise Photometry for the Two-WheeledKeplerMission

Vanderburg

Johnson

2014

Publications of the Astronomical Society of the Pacific

547

631

View full text Add to dashboard Cite

ABSTRACT. The original Kepler mission achieved high photometric precision thanks to ultrastable pointing enabled by use of four reaction wheels. The loss of two of these reaction wheels reduced the telescope's ability to point precisely for extended periods of time, and as a result, the photometric precision has suffered. We present a technique for generating photometric light curves from pixel-level data obtained with the two-wheeled extended Kepler mission, K2. Our photometric technique accounts for the nonuniform pixel response function of the Kepler detectors by correlating flux measurements with the spacecraft's pointing and removing the dependence. When we apply our technique to the ensemble of stars observed during the Kepler Two-Wheel Concept Engineering Test, we find improvements over raw K2 photometry by factors of 2-5, with noise properties qualitatively similar to Kepler targets at the same magnitudes. We find evidence that the improvement in photometric precision depends on each target's position in the Kepler field of view, with worst precision near the edges of the field. Overall, this technique restores the median-attainable photometric precision within a factor of two of the original Kepler photometric precision for targets ranging from 10th to 15th magnitude in the Kepler bandpass, peaking with a median precision within 35% to that of Kepler for stars between 12th and 13th magnitude in the Kepler bandpass.

show abstract

The Radius Distribution of Planets Around Cool Stars

Cited by 156 publications

References 64 publications

VettingKeplerplanet candidates in the sub-Jovian desert with multiband photometry

VettingKeplerplanet candidates in the sub-Jovian desert with multiband photometry

Advances in exoplanet science from Kepler

A Technique for Extracting Highly Precise Photometry for the Two-WheeledKeplerMission

Contact Info

Product

Resources

About