We report here on the discovery of stellar occultations, observed with Kepler, that recur periodically at 15.685 hour intervals, but which vary in depth from a maximum of 1.3% to a minimum that can be less than 0.2%. The star that is apparently being occulted is KIC 12557548, a V = 16 magnitude K dwarf with T eff,s 4400 K. The out-of-occultation behavior shows no evidence for ellipsoidal light variations, indicating that the mass of the orbiting object is less than ∼3 M J (for an orbital period of 15.7 hr). Because the eclipse depths are highly variable, they cannot be due solely to transits of a single planet with a fixed size. We discuss but dismiss a scenario involving a binary giant planet whose mutual orbit plane precesses, bringing one of the planets into and out of a grazing transit. This scenario seems ruled out by the dynamical instability that would result from such a configuration. We also briefly consider an eclipsing binary, possibly containing an accretion disk, that either orbits KIC 12557548 in a hierarchical triple configuration or is nearby on the sky, but we find such a scenario inadequate to reproduce the observations. The much more likely explanation-but one which still requires more quantitative development-involves macroscopic particles escaping the atmosphere of a slowly disintegrating planet not much larger than Mercury in size. The particles could take the form of micron-sized pyroxene or aluminum oxide dust grains. The planetary surface is hot enough to sublimate and create a high-Z atmosphere; this atmosphere may be loaded with dust via cloud condensation or explosive volcanism. Atmospheric gas escapes the planet via a Parkertype thermal wind, dragging dust grains with it. We infer a mass loss rate from the observations of order 1 M ⊕ /Gyr, with a dust-to-gas ratio possibly of order unity. For our fiducial 0.1M ⊕ planet (twice the mass of Mercury), the evaporation timescale may be ∼0.2 Gyr. Smaller mass planets are disfavored because they evaporate still more quickly, as are larger mass planets because they have surface gravities too strong to sustain outflows with the requisite mass-loss rates. The occultation profile evinces an ingress-egress asymmetry that could reflect a comet-like dust tail trailing the planet; we present simulations of such a tail.

We produce and analyze eclipse time variation (ETV) curves for some 2600 targeted main-field Kepler binaries. We find good to excellent evidence for a third body in 222 systems via either the light-travel-time (LTTE) or dynamical effect delays. Approximately half of these systems have been discussed in previous work, while the rest are newly reported here. Via detailed analysis of the ETV curves using high-level analytic approximations, we are able to extract system masses and information about the three-dimensional characteristics of the triple for 62 systems which exhibit both LTTE and dynamical delays. For the remaining 160 systems whose ETV curves are dominated by LTTE delays we are able to extract the outer orbital period, eccentricity, and longitude of periastron as well as the mass function of the triple. In general, our solutions improve upon those published earlier. New techniques of preprocessing the flux time series are applied to eliminate false positive triples and to enhance the ETV curves. The set of triples with outer orbital periods shorter than ∼2000 days is now sufficiently numerous for meaningful statistical analysis. We find that (i) as predicted, there is a peak near i m 40• in the distribution of the triple vs. inner binary mutual inclination angles that provides strong confirmation of the operation of Kozai-Lidov cycles with tidal friction; (ii) the median eccentricity of the third-body orbits is e 2 = 0.35; (iii) there is a deficit of triple systems with binary periods 1 day and outer periods between ∼50 and 200 days which might help guide the refinement of theories of the formation and evolution of close binaries; and (iv) the substantial fraction of Kepler binaries which have third-body companions is consistent with a very large fraction of all binaries being part of triples.

We present the results of a search through the photometric database of Kepler eclipsing binaries (Prša et al. 2011;Slawson et al. 2011) looking for evidence of hierarchical triple star systems. The presence of a third star orbiting the binary can be inferred from eclipse timing variations. We apply a simple algorithm in an automated determination of the eclipse times for all 2157 binaries. The "calculated" eclipse times, based on a constant period model, are subtracted from those observed. The resulting O − C (observed minus calculated times) curves are then visually inspected for periodicities in order to find triple star candidates. After eliminating false positives due to the beat frequency between the ∼1/2-hour Kepler cadence and the binary period, 39 candidate triple systems were identified. The periodic O − C curves for these candidates were then fit for contributions from both the classical Roemer delay and so-called "physical" delay, in an attempt to extract a number of the system parameters of the triple. We discuss the limitations of the information that can be inferred from these O −C curves without further supplemental input, e.g., ground-based spectroscopy. Based on the limited range of orbital periods for the triple star systems to which this search is sensitive, we can extrapolate to estimate that at least 20% of all close binaries have tertiary companions.

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Previous studies of large nuclear ribonucleoproteins (RNPs) containing mRNA and precursors of mRNA have been hampered by the heterogeneity of the material. Any one molecular species of RNA is generally present at a level of less than 1% of the total. Biochemical information about large nuclear RNPs is therefore limited to bulk properties, for the most part derived from analysis of a breakdown product of the RNP that sediments at about 30S in a sucrose gradient. This 30S complex, made up of a fragment of RNA and a set of basic proteins, is regarded as a subunit of the native structure (12,13,22).In the studies reported here, we have investigated cells containing amplified genes as a source of an abundant large nuclear RNP, with a view to the possible isolation and analysis of homogeneous material. We have used a mutant, simian virus 40 (SV40)-transformed Syrian hamster cell line in which the gene for a multifunctional enzyme abbreviated CAD (for carbamoyl-phosphate synthetase, aspartate transcarbamylase, dihydro-orotase) is amplified about 200-fold (7,11,16,27). The levels of CAD mRNA and protein show a corresponding increase, CAD mRNA making up about 1% of the cytoplasmic polyadenylated RNA (16,27). One of our first objectives was to determine whether CAD sequences are similarly enriched in nuclear RNA.A further feature of the CAD gene pertinent to studies of nuclear RNP is its size and complexity. The structure of the gene indicates that the primary transcript is 25 kilobases (kb) in length and contains 37 or more intervening sequences (17). Hybridization analysis reveals a mature mRNA of about 7.9 kb (16, 27). The great length of these molecules heightens interest in the mechanism of their packaging, processing, and transport and at the same time poses difficulties for biochemical studies, for example, the problem of instability due to a large target size for RNase. were grown in culture as described previously (24).Nuclear and cytoplasmic fractions. (i) Procedure 1. Approximately 108 cells scraped from subconfluent plates were washed three times with ice-cold 137 mM NaCI-8 mM Na2HPO4-1.5 mM KH2PO4-2.5 mM KCI, allowed to swell for 10 min in 2 ml of 10 mM Tris-hydrochloride -3 mM MgCl2 (pH 7.5) (TM), and lysed with 10 strokes of a Dounce homogenizer (B pestle) at 4°C. Nuclei were pelleted and washed, once with 1 ml of TM containing 0.5% Triton X-100 and once with 1 ml of TM. The postnuclear supernatant and detergent wash were combined and designated the cytoplasmic fraction.(ii) Procedure 2. Subconfluent plates were washed with 125 mM KCI-30 mM Tris-hydrochloride (pH 7.5;) mM magnesium acetate-1 mM 2-mercaptoethanol-2 mM ribonucleoside vanadyl complex (2)-0.15 mM spermine-0.05 mM spermidine at 4°C, and cells scraped from the plates were washed twice with the same buffer. Approximately 108 cells were allowed to swell for 10 min in 2.5 ml of swelling buffer (same as wash buffer except the KCl concentration was 10 mM), lysed with 20 strokes of a Dounce homogenizer (B pestle), overlaid on an equal volume of swellin...

We report the first confirmation of a hot Jupiter discovered by the Transiting Exoplanet Survey Satellite (TESS ) mission: HD 202772A b. The transit signal was detected in the data from TESS Sector 1, and was confirmed to be of planetary origin through radial velocity (RV) measurements. HD 202772A b is orbiting a mildly evolved star with a period of 3.3 days. With an apparent magnitude of V = 8.3, the star is among the brightest known to host a hot Jupiter. Based on the 27 days of TESS photometry, and RV data from the CHIRON and HARPS spectrographs, the planet has a mass of 1.008 +0.074 −0.079 M J and radius of 1.562 +0.053 −0.069 R J , making it an inflated gas giant. HD 202772A b is a rare example of a transiting hot Jupiter around a quickly evolving star. It is also one of the most strongly irradiated hot Jupiters currently known.