학술논문
Low-amplitude Solar-like Oscillations in the K5 V Star ϵ Indi A
Document Type
article
Author
Mia S. Lundkvist; Hans Kjeldsen; Timothy R. Bedding; Mark J. McCaughrean; R. Paul Butler; Ditte Slumstrup; Tiago L. Campante; Conny Aerts; Torben Arentoft; Hans Bruntt; Cátia V. Cardoso; Fabien Carrier; Laird M. Close; João Gomes da Silva; Thomas Kallinger; Robert R. King; Yaguang Li; Simon J. Murphy; Jakob L. Rørsted; Dennis Stello
Source
The Astrophysical Journal, Vol 964, Iss 2, p 110 (2024)
Subject
Language
English
ISSN
1538-4357
11665718
11665718
Abstract
We have detected solar-like oscillations in the mid-K-dwarf ϵ Indi A, making it the coolest dwarf to have measured oscillations. The star is noteworthy for harboring a pair of brown dwarf companions and a Jupiter-type planet. We observed ϵ Indi A during two radial velocity campaigns, using the high-resolution spectrographs HARPS (2011) and UVES (2021). Weighting the time series, we computed the power spectra and established the detection of solar-like oscillations with a power excess located at 5265 ± 110 μ Hz—the highest frequency solar-like oscillations so far measured in any star. The measurement of the center of the power excess allows us to compute a stellar mass of 0.782 ± 0.023 M _⊙ based on scaling relations and a known radius from interferometry. We also determine the amplitude of the peak power and note that there is a slight difference between the two observing campaigns, indicating a varying activity level. Overall, this work confirms that low-amplitude solar-like oscillations can be detected in mid-K-type stars in radial velocity measurements obtained with high-precision spectrographs.