Asteroseismology of red giants: photometric observations of Arcturus by SMEI

Abstract

We present new results on oscillations of the K1.5 III giant Arcturus (alpha Boo), from analysis of just over 2.5 yr of precise photometric observations made by the Solar Mass Ejection Imager (SMEI) on board the Coriolis satellite. A strong mode of oscillation is uncovered by the analysis, having frequency 3.51+/-0.03 micro-Hertz. By fitting its mode peak, we are able offer a highly constrained direct estimate of the damping time (tau = 24+/-1 days). The data also hint at the possible presence of several radial-mode overtones, and maybe some non-radial modes. We are also able to measure the properties of the granulation on the star, with the characteristic timescale for the granulation estimated to be 0.50+/-0.05 days.

arXiv comment6 pages, 5 figures; accepted for publication in MNRAS Letters

References in corpus (7)

• Detection of Solar-like Oscillations in the G7 Giant Star xi Hya
• Solar-like Oscillations (Invited Review)
• Excitation of solar-like oscillations across the HR diagram
• Oscillation mode lifetimes in ksi Hydrae: Will strong mode damping limit asteroseismology of red giant stars?
• Evidence for Granulation and Oscillations in Procyon from Photometry with the WIRE satellite
• Pulsations detected in the line profile variations of red giants: Modelling of line moments, line bisector and line shape
• Oscillations in Arcturus from WIRE photometry

Cited by in corpus (16)

• Gaia FGK Benchmark Stars: Effective temperatures and surface gravities
• Asteroseismology of red giants from the first four months of Kepler data: Fundamental parameters
• Mode lifetimes of stellar oscillations - Implications for asteroseismology
• Period-luminosity relations of pulsating M giants in the solar neighbourhood and the Magellanic Clouds
• Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields
• Assessing the accuracy of the gravity determination in late-type stars with solar-like pulsators
• Polaris the Cepheid returns: 4.5 years of monitoring from ground and space
• The Discovery of Stellar Oscillations in the K Giant $\iota$ Dra
• Oscillations in Beta UMi - Observations with SMEI
• The period and amplitude changes of Polaris (alpha UMi) from 2003 to 2007 measured with SMEI
• Nova light curves from the Solar Mass Ejection Imager (SMEI) - II. The extended catalog
• Amplitude variability in satellite photometry of the non-radially pulsating O9.5V star zeta Oph
• Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE - Constellation
• Oscillations in the G-type Giants
• SMEI observations of previously unseen pulsation frequencies in gamma Doradus
• An observer's view on the future of asteroseismology