학술논문
Low-amplitude solar-like oscillations in the K5 V star $\varepsilon$ Indi A
Document Type
Working Paper
Author
Lundkvist, Mia S.; Kjeldsen, Hans; Bedding, Timothy R.; McCaughrean, Mark J.; Butler, R. Paul; Slumstrup, Ditte; Campante, Tiago L.; Aerts, Conny; Arentoft, Torben; Bruntt, Hans; Cardoso, Cátia V.; Carrier, Fabien; Close, Laird M.; da Silva, João Gomes; Kallinger, Thomas; King, Robert R.; Li, Yaguang; Murphy, Simon J.; Rørsted, Jakob L.; Stello, Dennis
Source
Subject
Language
Abstract
We have detected solar-like oscillations in the mid K-dwarf $\varepsilon$ 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 $\varepsilon$ 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 $5265 \pm 110 \ \mu$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 $0.782 \pm 0.023 \ M_\odot$ 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.
Comment: 10 pages, 3 figures, accepted for publication in ApJ
Comment: 10 pages, 3 figures, accepted for publication in ApJ