Context: Convection in red giant stars excites resonant acoustic waves whose frequencies depend on the sound speed inside the star, which in turn depends on the properties of the stellar interior. Therefore, asteroseismology is the most robust available method for probing the internal structure of red giant stars. Aims: Solar-like oscillations in the red giant HR 7349 are investigated. Methods: Our study is based on a time series of 380 760 photometric measurements spread over 5 months obtained with the CoRoT satellite. Mode parameters were estimated using maximum likelihood estimation of the power spectrum. Results: The power spectrum of the high-precision time series clearly exhibits several identifiable peaks between 19 and 40 μHz showing regularity with a mean large and small spacing of Δ? = 3.47 ± 0.12 μHz and δ?02 = 0.65 ± 0.10 μHz. Nineteen individual modes are identified with amplitudes in the range from 35 to 115 ppm. The mode damping time is estimated to be 14.7+-2.94.7 days. © 2010 ESO.
Non-radial oscillations in the red giant HR 7349 measured by CoRoT / Carrier F.; De Ridder J.; Baudin F.; Barban C.; Hatzes A.P.; Hekker S.; Kallinger T.; Miglio A.; Montalban J.; Morel T.; Weiss W.W.; Auvergne M.; Baglin A.; Catala C.; Michel E.; Samadi R.. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - ELETTRONICO. - 509:1(2010), pp. A73.1-A73.8. [10.1051/0004-6361/200912749]
Non-radial oscillations in the red giant HR 7349 measured by CoRoT
Miglio A.;
2010
Abstract
Context: Convection in red giant stars excites resonant acoustic waves whose frequencies depend on the sound speed inside the star, which in turn depends on the properties of the stellar interior. Therefore, asteroseismology is the most robust available method for probing the internal structure of red giant stars. Aims: Solar-like oscillations in the red giant HR 7349 are investigated. Methods: Our study is based on a time series of 380 760 photometric measurements spread over 5 months obtained with the CoRoT satellite. Mode parameters were estimated using maximum likelihood estimation of the power spectrum. Results: The power spectrum of the high-precision time series clearly exhibits several identifiable peaks between 19 and 40 μHz showing regularity with a mean large and small spacing of Δ? = 3.47 ± 0.12 μHz and δ?02 = 0.65 ± 0.10 μHz. Nineteen individual modes are identified with amplitudes in the range from 35 to 115 ppm. The mode damping time is estimated to be 14.7+-2.94.7 days. © 2010 ESO.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
