Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO

• Type: Article in International Scientific Journal
• Date: 2024

Authors

Campante, TL (Author) FCUP; Kjeldsen, H (Author) Other; Li, Y (Author) Other; Lund, MN (Author) Other; Silva, AM (Author) Other; Corsaro, E (Author) Other; da Silva, JG (Author) Other; Martins, JHC (Author) Other; Adibekyan, V (Author) Other; Silva, TA (Author) Other; Bedding, TR (Author) Other; Bossini, D (Author) Other; Buzasi, DL (Author) Other; Chaplin, WJ (Author) Other; Costa, RR (Author) Other; Cunha, MS (Author) FCUP; Cristo, E (Author) Other; Faria, JP (Author) Other; Garcia, RA (Author) Other; Huber, D (Author) Other; Lundkvist, MS (Author) Other; Metcalfe, TS (Author) Other; Monteiro, MJPFG (Author) FCUP; Neitzel, AW (Author) Other; Nielsen, MB (Author) Other; Poretti, E (Author) Other; N.C. Santos (Author) FCUP; Sousa, SG (Author) FCUP

Journal

Title: Astronomy and Astrophysics

Vol. 683

Final page: L16

ISSN: 0004-6361

Publisher: EDP Sciences

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 1 Citation

Other information

Authenticus ID: P-010-8R5

DOI: 10.1051/0004-6361/202449197

Abstract (EN): Fuelled by space photometry, asteroseismology is vastly benefitting the study of cool main-sequence stars, which exhibit convection-driven solar-like oscillations. Even so, the tiny oscillation amplitudes in K dwarfs continue to pose a challenge to space-based asteroseismology. A viable alternative is offered by the lower stellar noise over the oscillation timescales in Doppler observations. In this Letter we present the definite detection of solar-like oscillations in the bright K5 dwarf & varepsilon; Indi based on time-intensive observations collected with the ESPRESSO spectrograph at the VLT, thus making it the coolest seismic dwarf ever observed. We measured the frequencies of a total of 19 modes of degree & ell; = 0-2 along with nu(max) = 5305 +/- 176 mu Hz and Delta nu = 201.25 +/- 0.16 mu Hz. The peak amplitude of radial modes is 2.6 +/- 0.5 cm s(-1), or a mere similar to 14% of the solar value. Measured mode amplitudes are similar to 2 times lower than predicted from a nominal L/M scaling relation and favour a scaling closer to (L/M)(1.5) below similar to 5500 K, carrying important implications for our understanding of the coupling efficiency between pulsations and near-surface convection in K dwarfs. This detection conclusively shows that precise asteroseismology of cool dwarfs is possible down to at least the mid-K regime using next-generation spectrographs on large-aperture telescopes, effectively opening up a new domain in observational asteroseismology.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10