Related papers: P-mode observations on Alpha Cen A

After more than one year of operation, the Kepler photometer has already provided exquisite data of solar-type stars. During the survey phase, 42 stars have been continuously observed. It appeared that five stars show evidence of…

We present the analysis of 3 hrs of a rapid time series of precise stellar radial velocity (RV) measurements (sigma = 4.5 m/s) of the cool Ap star Beta CrB. The integrated RV measurements spanning the wavelength interval 5000-6000 Ang. show…

We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1 to 3.1 GHz observations with the Australian Telescope Compact Array over 18 consecutive days in…

We present results of fitting the 50-day time series of photometry of alpha Cen A taken by the WIRE satellite in 1999. Both power spectrum and autocovariance function (ACF) fitting techniques were used in an attempt to determine mode…

$\alpha$ Centauri A is the closest solar-type star to the Sun and offers the best opportunity to find and ultimately to characterize an Earth-sized planet located in its Habitable Zone (HZ). Here we describe initial results from an ALMA…

Several attempts have been made to detect solar-like oscillations in the G0 IV star eta Boo. We present here new observations on this star simultaneously conducted with two spectrographs: Coralie mounted on the 1.2-m Swiss telescope at the…

The Sun's surface vibrates in characteristic 5-minute oscillations, known as p-modes, generated by sound waves trapped within the convection zone. Although these oscillations have long been hypothesized to reach into the solar wind, direct…

We present a list of "best possible" estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this…

Magnetic cycles of solar-like stars influence their internal physics. Thus, the frequency, amplitude, excitation rate, and damping of the acoustic oscillation modes (p-modes) vary with the cycle over time. We need to understand the impact…

We have used the star camera on the WIRE satellite to observe the K0 III star Alpha UMa, and we report the apparent detection of 10 oscillation modes. The lowest frequency mode is at 1.82 microhertz, and appears to be the fundamental mode.…

We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an…

We present first results from five XMM-Newton observations of the binary system Alpha Centauri, which has been observed in snapshot like exposures of roughly two hours each during the last two years. In all our observations the X-ray…

In the first spectroscopic campaign for a PG 1716 variable (or long-period pulsating subdwarf B star), we succeeded in detecting velocity variations due to g-mode pulsations at a level of 1.0-1.5 km/s.The observations were obtained during…

Excitation of solar-like oscillations is attributed to turbulent convection and takes place at the upper-most part of the outer convective zones. Amplitudes of these oscillations depend on the efficiency of the excitation processes as well…

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

Solar-like oscillations have been observed by Kepler and CoRoT in several solar-type stars, thereby providing a way to probe the stars using asteroseismology. We provide the mode frequencies of the oscillations of various stars required to…

Solar p-mode frequencies vary with solar activity. It is important to take this into account when comparing the frequencies observed from epochs that span different regions of the solar cycle. We present details of how to correct observed…

High quality observations of the low degree p-modes exist for almost two complete solar cycles using the solar spectrophotometer Mark-I, located and operating at the Observatorio del Teide (Tenerife, Spain). In this work, the observations…

We present high precision radial velocity measurements on the F5 IV star alpha CMi obtained by the SARG spectrograph at TNG (Telescopio Nazionale Galileo) exploiting the iodine cell technique. The time series of about 950 spectra of Procyon…

Aims. With the Solar Optical Telescope on Hinode, we investigate the basic properties of high-degree solar oscillations observed at two levels in the solar atmosphere, in the G-band (formed in the photosphere) and in the Ca II H line…