A theoretical approach for the interpretation of pulsating PMS intermediate-mass stars

The investigation of the pulsation properties of pre-main-sequence intermediate-mass stars is a promising tool to evaluate the intrinsic properties of these stars and to constrain current evolutionary models. Many new candidates of this class have been discovered during the last decade and very accurate data are expected from space observations obtained for example with the CoRoT satellite. In this context we aim at developing a theoretical approach for the interpretation of observed frequencies, both from the already available ground-based observations and from the future more accurate and extensive CoRoT results. To this purpose we have started a project devoted to the computations of fine and extensive grids of asteroseismic models of intermediate mass pre-main-sequence stars. The obtained frequencies are used to derive an analytical relation between the large frequency separation and the stellar luminosity and effective temperature and to develop a tool to compare theory and observations in the echelle diagram. The predictive capabilities of the proposed method are verified through the application to two test stars. As a second step, we apply the procedure to two true observations from multisite campaigns and we are able to constrain their stellar parameters, in particular the mass, in spite of the small number of frequencies. We expect that with a significantly higher number of frequencies both the stellar mass and age could be constrained and, at the same time, the physics of the models could be tested.Comment: Accepted for publication on A&

Multisite photometry of the pulsating Herbig Ae star V346 Ori

CONTEXT: The study of pulsation in Pre--Main--Sequence intermediate-mass stars represents an important tool for deriving information on fundamental stellar parameters and internal structure, as well as for testing current theoretical models. Interest in this class of variable stars has significantly increased during the last decade and about 30 members are presently known in the literature. AIMS: We have constructed the frequency spectrum of the oscillations in V346 Ori. We apply asteroseismic tools to these data to estimate the intrinsic parameters (mass, luminosity, effective temperature) of V346 Ori and to obtain information on its internal structure. METHODS: CCD time series photometry in the Johnson V filter has been obtained for a total of 145.7 h of observations distributed over 36 nights. The resulting light curves have been subjected to a detailed frequency analysis using updated numerical techniques. Photometric and spectroscopic data have also been acquired to determine reliable estimates of the stellar properties. RESULTS: We have identified 13 oscillation frequencies, 6 of which with higher significance. These have been compared with the predictions of non-radial adiabatic models. The resulting best fit model has a mass of 2.1$\pm$0.2 $M_{\odot}$, luminosity $\log{L/L_{\odot}}=1.37^{+0.11}_{-0.13}$, and effective temperature 7300$\pm$200 K. These values are marginally consistent with the association of V346 Ori to Orion OB1a. Alternatively, V346 Ori could be placed at a slightly larger distance than previously estimated.Comment: Accepted for publication on A&A. 14 Pages, 11 Figure

Matching the frequency spectrum of PMS stars by means of standard and rotating models

We applied the ATON code to the computation of detailed grids of standard (non--rotating) and rotating Pre--Main Sequence (PMS) models and computed their adiabatic oscillation spectra,with the aim of exploring the seismic properties of young stars. We adopt a method similar to the matching mode method by Guenther and Brown making use, when necessary, also of our rotating evolutionary code to compute the models for PMS stars. The method is described by a preliminary application to the frequency spectrum of two PMS stars (85 and 278) in the young open cluster NGC 6530. For the Star 85 we confirm, with self--consistent rotating models, previous interpretation of the data, attributing three close frequencies to the mode n=4, l=1 and m=0,+1,--1. For the Star 278 we find a different fit for the frequencies, corresponding to a model within the original error box of the star, and dispute the possibility thatthis star has an effective temperature much cooler that the red boundary of the radial instability strip.Comment: 9pages, 2 tables, 6 figures. Accepted to MNRA

Report on the CoRoT Evolution and Seismic Tools Activity

We present the work undertaken by the Evolution and Seismic Tools Activity (ESTA) team of the CoRoT Seismology Working Group. We have focused on two main tasks: Task 1 - now finished - has aimed at testing, comparing and optimising seven stellar evolution codes which will be used to model the internal structure and evolution of the CoRoT target stars. Task 2, still underway, aims at testing, comparing and optimising different seismic codes used to calculate the oscillations of models for different types of stars. The results already obtained are quite satisfactory, showing minor differences between the different numerical tools provided the same assumptions on the physical parameters are made. This work gives us confidence on the numerical tools that will be available to interpret the future CoRoT seismic data.Comment: To appear in: "The CoRoT Book", (Eds) F. Favata, A. Baglin & J. Lochard, ESA Publications Division, ESA S

CoRoT\,102699796, the first metal-poor Herbig Ae pulsator: a hybrid δ\delta Sct-γ\gamma Dor variable?

We present the analysis of the time series observations of CoRoT\,102699796 obtained by the CoRoT satellite that show the presence of five independent oscillation frequencies in the range 3.6-5 c/d. Using spectra acquired with FLAMES@VLT, we derive the following stellar parameters: spectral type F1V, T$_{\rm eff}$=7000$\pm$200 K, log(g)=$3.8\pm0.4$, [M/H]=$-1.1\pm0.2$, $v$sin$i$=$50\pm5$ km/s, L/L$_{\odot}$=21$^{+21}_{-11}$. Thus, for the first time we report the existence of a metal poor, intermediate-mass PMS pulsating star. Ground-based and satellite data are used to derive the spectral energy distribution of CoRoT\,102699796 extending from the optical to mid-infrared wavelengths. The SED shows a significant IR excess at wavelengths greater than $\sim5 \mu$. We conclude that CoRoT\,102699796 is a young Herbig Ae (F1Ve) star with a transitional disk, likely associated to the HII region [FT96]213.1-2.2. The pulsation frequencies have been interpreted in the light of the non-radial pulsation theory, using the LOSC code in conjunction with static and rotational evolutionary tracks. A minimization algorithm was used to find the best-fit model with M=1.84 M$_{\odot}$, T$_{\rm eff}$=6900 K which imply an isochronal age of t$\sim$2.5 Myr. This result is based on the interpretation of the detected frequencies as $g$-modes of low-moderate $n$-value. To our knowledge, this is the first time that such modes are identified in a intermediate-mass PMS pulsating star. Since CoRoT\,102699796 lies in the region of the HR diagram where the $\delta$ Sct and $\gamma$ Dor instability strips intersect, we argue that the observed pulsation characteristics are intermediate between these classes of variables, i.e. CoRoT\,102699796 is likely the first PMS hybrid $\gamma$ Dor-$\delta$ Sct pulsator ever studied.Comment: 13 pages, 7 figures. Accepted for publication in Monthly Notices of the RA

Impact of gastrointestinal side effects on patients’ reported quality of life trajectories after radiotherapy for prostate cancer: Data from the prospective, observational pros-it CNR study

Radiotherapy (RT) represents an important therapeutic option for the treatment of localized prostate cancer. The aim of the current study is to examine trajectories in patients’ reported quality of life (QoL) aspects related to bowel function and bother, considering data from the PROState cancer monitoring in ITaly from the National Research Council (Pros-IT CNR) study, analyzed with growth mixture models. Data for patients who underwent RT, either associated or not associated with androgen deprivation therapy, were considered. QoL outcomes were assessed over a 2-year period from the diagnosis, using the Italian version of the University of California Los Angeles-Prostate Cancer Index (Italian-UCLA-PCI). Three trajectories were identified for the bowel function; having three or more comorbidities and the use of 3D-CRT technique for RT were associated with the worst trajectory (OR = 3.80, 95% CI 2.04–7.08; OR = 2.17, 95% CI 1.22–3.87, respectively). Two trajectories were identified for the bowel bother scores; diabetes and the non-Image guided RT method were associated with being in the worst bowel bother trajectory group (OR = 1.69, 95% CI 1.06–2.67; OR = 2.57, 95% CI 1.70–3.86, respectively). The findings from this study suggest that the absence of comorbidities and the use of intensity modulated RT techniques with image guidance are related with a better tolerance to RT in terms of bowel side effects

Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study

Background: The National Research Council (CNR) prostate cancer monitoring project in Italy (Pros-IT CNR) is an observational, prospective, ongoing, multicentre study aiming to monitor a sample of Italian males diagnosed as new cases of prostate cancer. The present study aims to present data on the quality of life at time prostate cancer is diagnosed. Methods: One thousand seven hundred five patients were enrolled. Quality of life is evaluated at the time cancer was diagnosed and at subsequent assessments via the Italian version of the University of California Los Angeles-Prostate Cancer Index (UCLA-PCI) and the Short Form Health Survey (SF-12). Results: At diagnosis, lower scores on the physical component of the SF-12 were associated to older ages, obesity and the presence of 3+ moderate/severe comorbidities. Lower scores on the mental component were associated to younger ages, the presence of 3+ moderate/severe comorbidities and a T-score higher than one. Urinary and bowel functions according to UCLA-PCI were generally good. Almost 5% of the sample reported using at least one safety pad daily to control urinary loss; less than 3% reported moderate/severe problems attributable to bowel functions, and sexual function was a moderate/severe problem for 26.7%. Diabetes, 3+ moderate/severe comorbidities, T2 or T3-T4 categories and a Gleason score of eight or more were significantly associated with lower sexual function scores at diagnosis. Conclusions: Data collected by the Pros-IT CNR study have clarified the baseline status of newly diagnosed prostate cancer patients. A comprehensive assessment of quality of life will allow to objectively evaluate outcomes of different profile of care

The FRANEC stellar evolutionary code

We summarize the main physical assumptions and numerical procedures adopted by the FRANEC code to compute stellar models in all the evolutionary phases at hydrostatic and thermal equilibrium. An application to the Standard Solar Model is also briefly presented