13 research outputs found
TrES-2: The First Transiting Planet in the Kepler Field
We announce the discovery of the second transiting hot Jupiter discovered by
the Trans-atlantic Exoplanet Survey. The planet, which we dub TrES-2, orbits
the nearby star GSC 03549-02811 every 2.47063 days. From high-resolution
spectra, we determine that the star has T_eff = 5960 +/- 100 K and log(g) = 4.4
+/- 0.2, implying a spectral type of G0V and a mass of 1.08 +0.11/-0.05 M_sun.
High-precision radial-velocity measurements confirm a sinusoidal variation with
the period and phase predicted by the photometry, and rule out the presence of
line-bisector variations that would indicate that the spectroscopic orbit is
spurious. We estimate a planetary mass of 1.28 +0.09/-0.04 M_Jup. We model B,
r, R, and I photometric timeseries of the 1.4%-deep transits and find a
planetary radius of 1.24 +0.09/-0.06 R_Jup. This planet lies within the field
of view of the NASA Kepler mission, ensuring that hundreds of upcoming transits
will be monitored with exquisite precision and permitting a host of
unprecedented investigations.Comment: Accepted for publication in ApJL. 15 pages, 2 figure
TrES-4: A Transiting Hot Jupiter of Very Low Density
We report the discovery of TrES-4, a hot Jupiter that transits the star GSC 02620-00648 every 3.55 days. From high-resolution spectroscopy of the star, we estimate a stellar effective temperature of T_(eff) = 6100 ± 150 K, and from high-precision z and B photometry of the transit we constrain the ratio of the semimajor axis a and the stellar radius R_* to be a/R_* = 6.03 ± 0.13. We compare these values to model stellar isochrones to constrain the stellar mass to be M_* = 1.22 ± 0.17 M_⊙. Based on this estimate and the photometric time series, we constrain the stellar radius to be R_* = 1.738 ± 0.092 R_⊙ and the planet radius to be R_p = 1.674 ± 0.094 R_(Jup). We model our radial velocity data assuming a circular orbit and find a planetary mass of 0.84 ± 0.10 M_(Jup). Our radial velocity observations rule out line-bisector variations that would indicate a specious detection resulting from a blend of an eclipsing binary system. TrES-4 has the largest radius and lowest density of any of the known transiting planets. It presents a challenge to current models of the physical structure of hot Jupiters and indicates that the diversity of physical properties among the members of this class of exoplanets has yet to be fully explored
A positive psychological intervention using virtual reality for patients with advanced cancer in a hospital setting: a pilot study to assess feasibility
Purpose
This study presents data on the feasibility and possible benefits of a psychological intervention that uses virtual reality to induce positive emotions on adult hospitalized patients with metastatic cancer. The patient’s satisfaction and perceived utility was also examined.
Method
The sample was composed of 19 patients (53 % men, aged from 29 to 85 years old; x = 60.9; standard deviation = 14.54). The intervention consisted of four 30-min sessions during 1 week in which patients navigated through virtual environments designed to induce joy or relaxation. Mood was assessed before and after each session using the Visual Analog Scale. Patient satisfaction was assessed after each session and at the end of the intervention. Qualitative data were also collected with open-ended questions.
Results
There were no major difficulties with the use of devices, and any difficulties that did arise were solved through practice. There were adequate levels of pleasantness and perceived utility of the proposed intervention. The main perceived benefits were distraction, entertainment, and promotion of relaxation states. Regarding mood changes, an increase in positive emotions and a decrease in negative emotions were also detected.
Conclusions
The intervention was positively assessed and rated as minimally uncomfortable. Future actions are discussed as well as the need to implement brief interventions that take into account the patients’ medical state and physical discomfort level, especially with those in the advanced stages of disease