301 research outputs found

    KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane

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    We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian Mplanet=4.5±1.3 MJM_{\rm planet} = 4.5\pm 1.3\,M_J planet orbiting an F or G dwarf Mhost=1.5±0.4 M⊙M_{\rm host} = 1.5\pm 0.4\,M_\odot, which lies physically within {\cal O}(10\,\pc) of the Galactic plane. The source star is a heavily extincted AI∌5.2A_I\sim 5.2 luminous giant that has the lowest Galactic latitude, b=−0.28∘b=-0.28^\circ, of any planetary microlensing event. The relatively blue blended light is almost certainly either the host or its binary companion, with the first explanation being substantially more likely. This blend dominates the light at II band and completely dominates at RR and VV bands. Hence, the lens system can be probed by follow-up observations immediately, i.e., long before the lens system and the source separate due to their relative proper motion. The system is well characterized despite the low cadence Γ=0.15\Gamma=0.15--0.20 hr−10.20\,{\rm hr^{-1}} of observations and short viewing windows near the end of the bulge season. This suggests that optical microlensing planet searches can be extended to the Galactic plane at relatively modest cost.Comment: 35 pages, 3 Tables, 8 figure

    OGLE-2018-BLG-0532Lb: Cold Neptune With Possible Jovian Sibling

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    We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious signatures in the light curve that lead to an estimate of the planet-host mass ratio q=Mplanet/Mhost≃1×10−4q=M_{\rm planet}/M_{\rm host}\simeq 1\times10^{-4}. Although there are no obvious systematic residuals to this double-lens/single-source (2L1S) fit, we find that χ2\chi^2 can be significantly improved by adding either a third lens (3L1S, Δχ2=81\Delta\chi^2=81) or second source (2L2S, Δχ2=65\Delta\chi^2=65) to the lens-source geometry. After thorough investigation, we conclude that we cannot decisively distinguish between these two scenarios and therefore focus on the robustly-detected planet. However, given the possible presence of a second planet, we investigate to what degree and with what probability such additional planets may affect seemingly single-planet light curves. Our best estimates for the properties of the lens star and the secure planet are: a host mass M∌0.25 M⊙M\sim 0.25\,M_\odot, system distance DL∌1 D_L\sim 1\,kpc and planet mass mp,1=8 M⊕m_{p,1}= 8\,M_\oplus with projected separation a1,⊄=1.4 a_{1,\perp}=1.4\,au. However, there is a relatively bright I=18.6I=18.6 (and also relatively blue) star projected within <50 <50\,mas of the lens, and if future high-resolution images show that this is coincident with the lens, then it is possible that it is the lens, in which case, the lens would be both more massive and more distant than the best-estimated values above.Comment: 48 pages, 9 figures, 7 table

    SpitzerSpitzer Parallax of OGLE-2018-BLG-0596: A Low-mass-ratio Planet around an M-dwarf

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    We report the discovery of a SpitzerSpitzer microlensing planet OGLE-2018-BLG-0596Lb, with preferred planet-host mass ratio q∌2×10−4q \sim 2\times10^{-4}. The planetary signal, which is characterized by a short (∌1 day)(\sim 1~{\rm day}) "bump" on the rising side of the lensing light curve, was densely covered by ground-based surveys. We find that the signal can be explained by a bright source that fully envelops the planetary caustic, i.e., a "Hollywood" geometry. Combined with the source proper motion measured from GaiaGaia, the SpitzerSpitzer satellite parallax measurement makes it possible to precisely constrain the lens physical parameters. The preferred solution, in which the planet perturbs the minor image due to lensing by the host, yields a Uranus-mass planet with a mass of Mp=13.9±1.6 M⊕M_{\rm p} = 13.9\pm1.6~M_{\oplus} orbiting a mid M-dwarf with a mass of Mh=0.23±0.03 M⊙M_{\rm h} = 0.23\pm0.03~M_{\odot}. There is also a second possible solution that is substantially disfavored but cannot be ruled out, for which the planet perturbs the major image. The latter solution yields Mp=1.2±0.2 M⊕M_{\rm p} = 1.2\pm0.2~M_{\oplus} and Mh=0.15±0.02 M⊙M_{\rm h} = 0.15\pm0.02~M_{\odot}. By combining the microlensing and GaiaGaia data together with a Galactic model, we find in either case that the lens lies on the near side of the Galactic bulge at a distance DL∌6±1 kpcD_{\rm L} \sim 6\pm1~{\rm kpc}. Future adaptive optics observations may decisively resolve the major image/minor image degeneracy.Comment: 34 pages, 8 figures, Submitted to AAS journa

    KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane

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    We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian M_(planet) = 5.0 ± 1.2 M_J planet orbiting an F or G dwarf M_(host) = 1.2 ± 0.3 M⊙, which lies physically within O(10 pc) of the Galactic plane. The source star is a heavily extincted A_I ~ 5.2 luminous giant that has the lowest Galactic latitude, b = −0.°28, of any planetary microlensing event. The relatively blue blended light is almost certainly either the host or its binary companion, with the first explanation being substantially more likely. This blend dominates the light at the I band and completely dominates at the R and V bands. Hence, the lens system can be probed by follow-up observations immediately, i.e., long before the lens system and the source separate due to their relative proper motion. The system is well characterized despite the low cadence, Γ = 0.15–0.20 hr⁻Âč, of observations and short viewing windows near the end of the bulge season. This suggests that optical microlensing planet searches can be extended to the Galactic plane at relatively modest cost

    A Dynamical Systems Model for Combinatorial Cancer Therapy Enhances Oncolytic Adenovirus Efficacy by MEK-Inhibition

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    Oncolytic adenoviruses, such as ONYX-015, have been tested in clinical trials for currently untreatable tumors, but have yet to demonstrate adequate therapeutic efficacy. The extent to which viruses infect targeted cells determines the efficacy of this approach but many tumors down-regulate the Coxsackievirus and Adenovirus Receptor (CAR), rendering them less susceptible to infection. Disrupting MAPK pathway signaling by pharmacological inhibition of MEK up-regulates CAR expression, offering possible enhanced adenovirus infection. MEK inhibition, however, interferes with adenovirus replication due to resulting G1-phase cell cycle arrest. Therefore, enhanced efficacy will depend on treatment protocols that productively balance these competing effects. Predictive understanding of how to attain and enhance therapeutic efficacy of combinatorial treatment is difficult since the effects of MEK inhibitors, in conjunction with adenovirus/cell interactions, are complex nonlinear dynamic processes. We investigated combinatorial treatment strategies using a mathematical model that predicts the impact of MEK inhibition on tumor cell proliferation, ONYX-015 infection, and oncolysis. Specifically, we fit a nonlinear differential equation system to dedicated experimental data and analyzed the resulting simulations for favorable treatment strategies. Simulations predicted enhanced combinatorial therapy when both treatments were applied simultaneously; we successfully validated these predictions in an ensuing explicit test study. Further analysis revealed that a CAR-independent mechanism may be responsible for amplified virus production and cell death. We conclude that integrated computational and experimental analysis of combinatorial therapy provides a useful means to identify treatment/infection protocols that yield clinically significant oncolysis. Enhanced oncolytic therapy has the potential to dramatically improve non-surgical cancer treatment, especially in locally advanced or metastatic cases where treatment options remain limited.National Institutes of Health (U.S.) (Grant R01 CA118545)National Institutes of Health (U.S.) (Grant R01 CA095701)National Institutes of Health (U.S.) (Grant U54 CA11297)National Institutes of Health (U.S.) (Grant U54-CA112967
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