A Third Planet Orbiting HIP 14810

We present new precision radial velocities and a three-planet Keplerian orbit fit for the V = 8.5, G5 V star HIP 14810. We began observing this star at Keck Observatory as part of the N2K Planet Search Project. Wright et al. (2007) announced the inner two planets to this system, and subsequent observations have revealed the outer planet planet and the proper orbital solution for the middle planet. The planets have minimum masses of 3.9, 1.3, and 0.6 M_Jup and orbital periods of 6.67, 147.7, and 952 d, respectively. We have numerically integrated the family of orbital solutions consistent with the data and find that they are stable for at least 10^6 yr. Our photometric search shows that the inner planet does not transit.Comment: ApJL, accepte

Developing Complex Societies in Southeast Asia: Using Archaeological and Historical Evidence

A number of archaeologists are making significant advances in the historical archaeology of Southeast Asia. The papers presented in this issue, and the one that preceded it, provide new insights and exciting directions for future research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44539/1/10761_2004_Article_417784.pd

Revised Orbit and Transit Exclusion for HD 114762b

Transiting planets around bright stars have allowed the detailed follow-up and characterization of exoplanets, such as the study of exoplanetary atmospheres. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) is refining the orbits of the known exoplanets to confirm or rule out both transit signatures and the presence of additional companions. Here we present results for the companion orbiting HD 114762 in an eccentric 84 day orbit. Radial velocity analysis performed on 19 years of Lick Observatory data constrain the uncertainty in the predicted time of mid-transit to ~5 hours, which is less than the predicted one-half day transit duration. We find no evidence of additional companions in this system. New photometric observations with one of our Automated Photoelectric Telescopes (APTs) at Fairborn Observatory taken during a revised transit time for companion b, along with 23 years of nightly automated observations, allow us to rule out on-time central transits to a limit of ~0.001 mag. Early or late central transits are ruled out to a limit of ~0.002 mag, and transits with half the duration of a central transit are ruled out to a limit of ~0.003 mag.Comment: 5 pages, 2 figures, accepted for publication in ApJ

The NASA-UC Eta-Earth Program: III. A Super-Earth orbiting HD 97658 and a Neptune-mass planet orbiting Gl 785

We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modelling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msini = 8.2 +/- 1.2 M_Earth, orbital period P = 9.494 +/- 0.005 d, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msini = 21.6 +/- 2.0 M_Earth, P = 74.39 +/- 0.12 d, and orbital eccentricity 0.30 +/- 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.Comment: Submitted to ApJ, 7 pages, 6 figures, 5 table

Retired A Stars and Their Companions IV. Seven Jovian Exoplanets from Keck Observatory

We report precise Doppler measurements of seven subgiants from Keck Observatory. All seven stars show variability in their radial velocities consistent with planet-mass companions in Keplerian orbits. The host stars have masses ranging from 1.1 < Mstar/Msun < 1.9, radii 3.4 < Rstar/Rsun < 6.1, and metallicities -0.21 < [Fe/H] < +0.26. The planets are all more massive than Jupiter (Msini > 1 Mjup) and have semimajor axes > 1 AU. We present millimagnitude photometry from the T3 0.4m APT at Fairborn observatory for five of the targets. Our monitoring shows these stars to be photometrically stable, further strengthening the interpretation of the observed radial velocity variability. The orbital characteristics of the planets thus far discovered around former A-type stars are very different from the properties of planets around dwarf stars of spectral type F, G and K, and suggests that the formation and migration of planets is a sensitive function of stellar mass. Three of the planetary systems show evidence of long-term, linear trends indicative of additional distant companions. These trends, together with the high planet masses and increased occurrence rate, indicate that A-type stars are very promising targets for direct imaging surveys.Comment: PASP Accepted, final submission awaiting comments from the communit

Two Exoplanets Discovered at Keck Observatory

We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with Msini = 27.5 M_earth in a 14.48 d, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m/s. HD 73534 is a G5 subgiant with a Jupiter-like planet of Msini = 1.1 M_jup and K = 16 m/s in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity semiamplitudes, K, comparable to the radial velocity uncertainties. For exoplanets with periods longer than 10 days, the observed exoplanet eccentricity distribution is nearly flat for large amplitude systems (K > 80 m/s), but rises linearly toward low eccentricity for lower amplitude systems (K > 20 m/s).Comment: 8 figures, 6 tables, accepted, Ap

The California Planet Survey II. A Saturn-Mass Planet Orbiting the M Dwarf Gl649

We report precise Doppler measurements of the nearby (d = 10.34 pc) M dwarf Gl649 that reveal the presence of a planet with a minimum mass Msini = 0.328 Mjup in an eccentric (e = 0.30), 598.3 day orbit. Our photometric monitoring reveals Gl649 to be a new variable star with brightness changes on both rotational and decadal timescales. However, neither of these timescales are consistent with the 600-day Doppler signal and so provide strong support for planetary reflex motion as the best interpretation of the observed radial velocity variations. Gl649b is only the seventh Doppler-detected giant planet around an M dwarf. The properties of the planet and host-star therefore contribute significant information to our knowledge of planet formation around low-mass stars. We revise and refine the occurrence rate of giant planets around M dwarfs based on the California Planet Survey sample of low-mass stars (M* < 0.6 Msun). We find that f = 3.4^{+2.2}_{-0.9}% of stars with M* < 0.6 Msun harbor planets with Msini > 0.3$ Mjup and a < 2.5 AU. When we restrict our analysis to metal-rich stars with [Fe/H] > +0.2 we find the occurrence rate is 10.7^{+5.9}_{-4.2}%.Comment: 8 pages, 4 figures, 3 tables, PASP accepte

The NASA-UC Eta-Earth Program: I. A Super-Earth Orbiting HD 7924

We report the discovery of the first low-mass planet to emerge from the NASA-UC Eta-Earth Program, a super-Earth orbiting the K0 dwarf HD 7924. Keplerian modeling of precise Doppler radial velocities reveals a planet with minimum mass M_P sin i = 9.26 M_Earth in a P = 5.398 d orbit. Based on Keck-HIRES measurements from 2001 to 2008, the planet is robustly detected with an estimated false alarm probability of less than 0.001. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 7924 is photometrically constant over the radial velocity period to 0.19 mmag, supporting the existence of the planetary companion. No transits were detected down to a photometric limit of ~0.5 mmag, eliminating transiting planets with a variety of compositions. HD 7924b is one of only eight planets known with M_P sin i < 10 M_Earth and as such is a member of an emerging family of low-mass planets that together constrain theories of planet formation.Comment: ApJ accepted, 10 pages, 10 figures, 4 table

Scaling laws governing stochastic growth and division of single bacterial cells

Uncovering the quantitative laws that govern the growth and division of single cells remains a major challenge. Using a unique combination of technologies that yields unprecedented statistical precision, we find that the sizes of individual Caulobacter crescentus cells increase exponentially in time. We also establish that they divide upon reaching a critical multiple ($\approx$1.8) of their initial sizes, rather than an absolute size. We show that when the temperature is varied, the growth and division timescales scale proportionally with each other over the physiological temperature range. Strikingly, the cell-size and division-time distributions can both be rescaled by their mean values such that the condition-specific distributions collapse to universal curves. We account for these observations with a minimal stochastic model that is based on an autocatalytic cycle. It predicts the scalings, as well as specific functional forms for the universal curves. Our experimental and theoretical analysis reveals a simple physical principle governing these complex biological processes: a single temperature-dependent scale of cellular time governs the stochastic dynamics of growth and division in balanced growth conditions.Comment: Text+Supplementar