Metallicity vs. Be phenomenon relation in the solar neighborhood

Fast rotation seems to be the mayor factor to trigger the Be phenomenon. Surface fast rotation can be favored by initial formation conditions, such as abundance of metals. We have observed 118 Be stars up to the apparent magnitudes V=9 mag. Models of fast rotating atmospheres and evolutionary tracks were used to interpret the stellar spectra and to determine the stellar fundamental parameters. Since the studied stars are formed in regions that are separated enough to imply some non negligible gradient of galactic metallicity, we study the effects of possible incidence of this gradient on the nature as rotators of the studied stars.Comment: 3 pages ; to appear in the proceedings of the Sapporo meeting on active OB stars ; ASP Conference Series ; eds: S. Stefl, S. Owocki and A. Okazak

Achernar: Rapid Polarization Variability as Evidence of Photospheric and Circumstellar Activity

We present the results of a high accuracy ($\sigma \approx 0.005$) polarization monitoring of the Be Star Achernar that was carried out between July 7th and November 5th, 2006. Our results indicate that, after a near quiescent phase from 1998 to 2002, Achernar is presently in an active phase and has built a circumstellar disk. We detect variations both in the polarization level and position angle in timescales as short as one hour and as long as several weeks. Detailed modeling of the observed polarization strongly suggests that the short-term variations originate from discrete mass ejection events which produce transient inhomogeneities in the inner disk. Long-term variations, on the other hand, can be explained by the formation of an inner ring following one or several mass ejection events.Comment: 16 pages, 5 figures, Accepted to Ap

Evolution of the circumstellar disc of alpha Eri

The Halpha line emission formation region in the circumstellar disc of alpha Eri is: a) extended with a steep outward matter density decline during low H$\alpha$ emission phases; b) less extended with rather constant density distribution during the strong Halpha emission. The long-term variation of the Halpha emission has a 14-15 year cyclic B-Be phase transition. The disc formation time scales agree with the viscous decretion model. The time required for the disc dissipation is longer than expected from the viscous disc model.Comment: 3 pages ; to appear in the proceedings of the Sapporo meeting on active OB stars ; ASP Conference Series ; eds: S. Stefl, S. Owocki and A. Okazak

Multi-periodicity of the Be star η Centauri from spectroscopic and photometric observations

Abstract. We present photometric data and 209 highresolution, high signal-to-noise ratio optical spectra of the Be star η Centauri obtained in 1993 and 1995, respectively. Time series analysis of these and other data, performed using the CLEAN, CLEANEST and Fourier Doppler Imaging techniques, show the presence of multiperiodic variations. They are interpreted in terms of low and high order non-radial pulsation modes. A strong frequency of 1.29 c/d is detected in line profile and photometric variations. It is attributed to a mode with l = 2. Other high amplitude signals present in spectroscopic data are 1.78 c/d, 3.82 c/d and 4.51 c/d. A frequency of 1.48 c/d appearing in spectroscopic data is compatible with the 1.56 c/d periodicity largely dominant in observations taken prior to 1993. The corresponding "superperiods" for four of the frequencies are commensurate at the 8% level. The star showed period and non-radial pulsation degree variations in timescales as short as ∼ 1.5 hour. The dominant mode apparently alternates between l = 2 and l = 4 every other day during the eight day time span. This could be a modulation linked to the superperiod or to the stellar rotation. The main periodicities detected in our analysis are compatible with theoretical unstable g modes in SPB variables. Short time scale variability (1 − 3 hr), typical of high-order p modes is also systematically present

A multispectral view of the periodic events in eta Carinae

A full description of the 5.5-yr low excitation events in Eta Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two components. The first, the 'slow variation' component, is revealed by slow changes in the ionization level of circumstellar matter across the whole cycle and is caused by gradual changes in the wind-wind collision shock-cone orientation, angular opening and gaseous content. The second, the 'collapse' component, is restricted to around the minimum, and is due to a temporary global collapse of the wind-wind collision shock. High energy photons (E > 16 eV) from the companion star are strongly shielded, leaving the Weigelt objects at low ionization state for >6 months. High energy phenomena are sensitive only to the 'collapse', low energy only to the 'slow variation' and intermediate energies to both components. Simple eclipses and mechanisms effective only near periastron (e.g., shell ejection or accretion onto the secondary star) cannot account for the whole 5.5-yr cycle. We find anti-correlated changes in the intensity and the radial velocity of P Cygni absorption profiles in FeII 6455 and HeI 7065 lines, indicating that the former is associated to the primary and the latter to the secondary star. We present a set of light curves representative of the whole spectrum, useful for monitoring the next event (2009 January 11).Comment: 16 pages, 7 EPS figures, accepted for publication on MNRA

Complementary and Integrative Health Practices in a Brazilian Freestanding Birth Center: A Cross-Sectional Study

The study aimed to analyze the use of complementary and integrative health practices (CIHPs) during labor and birth in a freestanding birth center. A total of 28 different CIHPs were applied with or used by laboring women. The most adopted CIHPs were mind-body practices (99.9%) and natural products (35.5%), mostly used by primiparous women (P <.05). Adopting CIHPs can increase care quality, increase positive experiences during childbirth, and promote evidence-based choices

Perineal pain effect on the activities of women who had an episiotomy

Objective: This manuscript discusses the influence of the perineal pain after normal birth on daily activities of women who had an episiotomy. Methods: Descriptive study with data collected through interviews performed from 20 to 48 hours after delivery, with 52 women, applying the pain numeric scale (0-10). Results: Perineal pain was present in 86.5% and 82.7% of women, at 20 and 48 hours after delivery, respectively. There was a predominance of mild pain (64.4% to 72.1%), followed by moderate pain (28.9% to 18.6%). The restriction of the activities varied between 92.3% and 86.5% women, from 20 to 48 hours after delivery, respectively. Conclusions: Although most women had reported mild pain, it was noted that this morbidity limits the essential activities

The periodicity of the η Carinae events

Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well-defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of Ppres = 2022.7 ± 1.3 d. Spectroscopic data collected during the last 60 yr yield an average period of Pavg = 2020 ± 4 d, consistent with the present-day period. The period cannot have changed by more than ΔP/P = 0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of He I 6678 to define the epoch of the Cycle 11 minimum, T0 = JD 245 2819.8. The next event is predicted to occur on 2009 January 11 (±2 d). The dates for the start of the minimum in other spectral features and broad-bands are very close to this date, and have well-determined time-delays from the He I epoch.Facultad de Ciencias Astronómicas y Geofísica

The periodicity of the Eta Carinae events

Fil: Damineli, A. Universidade de Sao Paulo; BrasilFil: Hillier, D. J. University of Pittsburgh; Estados UnidosFil: Corcoran, Michael. National Aeronautics and Space Administration; Estados Unidos.Fil: Corcoran, Michael. CRESST and X-ray Astrophysics Laboratory; Estados UnidosFil: Stahl, O. Zentrum für Astronomie. Universität Heidelberg; AlemaniaFil: Levenhagen, R. S.. Universidade de Sao Paulo; BrasilFil: Leister, N. V.. Universidade de Sao Paulo; BrasilFil: Groh, J. H.. Universidade de Sao Paulo; BrasilFil: Teodoro, M.. Universidade de Sao Paulo; BrasilFil: Albacete Colombo, Juan F. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Gonzalez, Jorge F. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; ArgentinaFil: Arias, Julia I. Universidad de La Serena; ChileFil: Levato, Orlando H. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; ArgentinaFil: Grosso, Monica G. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; ArgentinaFil: Morrell, Nidia I. Las Campanas Observatory; ChileFil: Gamen, Roberto C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; ArgentinaFil: Wallerstein, G. University of Washington; Estados UnidosFil: Niemela, Virpi S. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Albacete Colombo, Juan F. Universidad Nacional de Río Negro; ArgentinaExtensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and welldefined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of Ppres = 2022.7 ± 1.3 d. Spectroscopic data collected during the last 60 yr yield an average period of Pavg = 2020 ± 4 d, consistent with the present-day period. The period cannot have changed by more than P/P = 0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of He I 6678 to define the epoch of the Cycle 11 minimum, T0 = JD 245 2819.8. The next event is predicted to occur on 2009 January 11 (±2 d). The dates for the start of the minimum in other spectral features and broad-bands are very close to this date, and have well-determined time-delays from the He I epoch