KEPLER's First Rocky Planet: Kepler-10b

Astrophysical Journal - ASTROPHYS J 02/2011; 729. DOI: 10.1088/0004-637X/729/1/27
Source: arXiv

ABSTRACT NASA's Kepler Mission uses transit photometry to determine the frequency of
earth-size planets in or near the habitable zone of Sun-like stars. The mission
reached a milestone toward meeting that goal: the discovery of its first rocky
planet, Kepler-10b. Two distinct sets of transit events were detected: 1) a 152
+/- 4 ppm dimming lasting 1.811 +/- 0.024 hours with ephemeris
T[BJD]=2454964.57375+N*0.837495 days and 2) a 376 +/- 9 ppm dimming lasting
6.86 +/- 0.07 hours with ephemeris T[BJD]=2454971.6761+N*45.29485 days.
Statistical tests on the photometric and pixel flux time series established the
viability of the planet candidates triggering ground-based follow-up
observations. Forty precision Doppler measurements were used to confirm that
the short-period transit event is due to a planetary companion. The parent star
is bright enough for asteroseismic analysis. Photometry was collected at
1-minute cadence for >4 months from which we detected 19 distinct pulsation
frequencies. Modeling the frequencies resulted in precise knowledge of the
fundamental stellar properties. Kepler-10 is a relatively old (11.9 +/- 4.5
Gyr) but otherwise Sun-like Main Sequence star with Teff=5627 +/- 44 K,
Mstar=0.895 +/- 0.060 Msun, and Rstar=1.056 +/- 0.021 Rsun. Physical models
simultaneously fit to the transit light curves and the precision Doppler
measurements yielded tight constraints on the properties of Kepler-10b that
speak to its rocky composition: Mpl=4.56 +/- 1.29 Mearth, Rpl=1.416 +/- 0.036
Rearth, and density=8.8 +/- 2.9 gcc. Kepler-10b is the smallest transiting
exoplanet discovered to date.

1 Follower
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The success of the International Ultraviolet Explorer (IUE) first and then of the STIS and COS spectrographs on-board the Hubble Space Telescope (HST) demonstrate the impact that observations at UV wavelengths had and are having on modern astronomy. Several discoveries in the exoplanet field have been done at UV wavelengths. Nevertheless, the amount of data collected in this band is still limited both in terms of observed targets and time spent on each of them. For the next decade, the post-HST era, the only large (2-m class) space telescope capable of UV observations will be the World Space Observatory-UltraViolet (WSO-UV). In its characteristics, the WSO-UV mission is similar to that of HST, but all observing time will be dedicated to UV astronomy. In this work, we briefly outline the major prospects of the WSO-UV mission in terms of exoplanet studies. To the limits of the data and tools currently available, here we also compare the quality of key exoplanet data obtained in the far-UV and near-UV with HST (STIS and COS) to that expected to obtain with WSO-UV.
    Astrophysics and Space Science 11/2014; 354(1):9-19. DOI:10.1007/s10509-014-2027-3 · 2.40 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31-d orbit accompanied by a more massive outer companion in an eccentric (e=0.3) 223-d orbit. The outer giant planet, Kepler-424c, is not detected to transit the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets, the appear to be "lonely" (e.g. Steffen et al.~2012). This might be a consequence of a highly dynamical past of these systems. The Kepler-424 planetary system is a system with a hot Jupiter in a multiple system, similar to upsilon Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127; Gandolfi et al.~2013), Kepler-43 (KOI-135; Bonomo et al.~2012), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope and HET. For all systems we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have a heavy elements content between 20 and 120 M_Earth.
    The Astrophysical Journal 09/2014; 795(2). DOI:10.1088/0004-637X/795/2/151 · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The chemical composition of stars hosting small exoplanets (with radii less than four Earth radii) appears to be more diverse than that of gas-giant hosts, which tend to be metal-rich. This implies that small, including Earth-size, planets may have readily formed at earlier epochs in the Universe's history when metals were more scarce. We report Kepler spacecraft observations of Kepler-444, a metal-poor Sun-like star from the old population of the Galactic thick disk and the host to a compact system of five transiting planets with sizes between those of Mercury and Venus. We validate this system as a true five-planet system orbiting the target star and provide a detailed characterization of its planetary and orbital parameters based on an analysis of the transit photometry. Kepler-444 is the densest star with detected solar-like oscillations. We use asteroseismology to directly measure a precise age of 11.2+/-1.0 Gyr for the host star, indicating that Kepler-444 formed when the Universe was less than 20% of its current age and making it the oldest known system of terrestrial-size planets. We thus show that Earth-size planets have formed throughout most of the Universe's 13.8-billion-year history, leaving open the possibility for the existence of ancient life in the Galaxy. The age of Kepler-444 not only suggests that thick-disk stars were among the hosts to the first Galactic planets, but may also help to pinpoint the beginning of the era of planet formation.

Full-text (3 Sources)

Available from
May 21, 2014