ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Study of chemically peculiar stars - I. High-resolution spectroscopy and K2 photometry of Am stars in the region of M44

Joshi, S and Trust, O and Semenko, E and Williams, PE and Lampens, P and De Cat, P and Vermeylen, L and Holdsworth, DL and García, RA and Mathur, S and Santos, ARG and Mkrtichian, D and Goswami, A and Cuntz, M and Yadav, AP and Sarkar, M and Bhatt, BC and AliÃavuÅ, FK and Nhlapo, MD and Lund, MN and Goswami, PP and Savanov, I and Jorissen, A and Jurua, E and Avvakumova, E and Dmitrienko, ES and Chakradhari, NK and Das, MK and Chowdhury, S and Abedigamba, OP and Yakunin, I and Letarte, B and Karinkuzhi, D (2022) Study of chemically peculiar stars - I. High-resolution spectroscopy and K2 photometry of Am stars in the region of M44. In: Monthly Notices of the Royal Astronomical Society, 510 (4). pp. 5854-5871.

Full text not available from this repository.
Official URL: https://doi.org/10.1093/mnras/stab3158

Abstract

We present a study based on the high-resolution spectroscopy and K2 space photometry of five chemically peculiar stars in the region of the open cluster M44. The analysis of the high-precision photometric K2 data reveals that the light variations in HD 73045 and HD 76310 are rotational in nature and caused by spots or cloud-like co-rotating structures, which are non-stationary and short-lived. The time-resolved radial velocity measurements, in combination with the K2 photometry, confirm that HD 73045 does not show any periodic variability on time-scales shorter than 1.3 d, contrary to previous reports in the literature. In addition to these new rotational variables, we discovered a new heartbeat system, HD 73619, where no pulsational signatures are seen. The spectroscopic and spectropolarimetric analyses indicate that HD 73619 belongs to the peculiar Am class, with either a weak or no magnetic field, considering the 200-G detection limit of our study. The least-squares deconvolution profiles for HD 76310 indicate a complex structure in its spectra, suggesting that this star is either part of a binary system or surrounded by a cloud shell. When placed in the Hertzsprung-Russell diagram, all studied stars are evolved from the main sequence and situated in the δScuti instability strip. This work is relevant for further detailed studies of chemically peculiar stars, for example on inhomogeneities (including spots) in the absence of magnetic fields and the origin of the pulsational variability in heartbeat systems.

Item Type: Journal Article
Publication: Monthly Notices of the Royal Astronomical Society
Publisher: Oxford University Press
Additional Information: The copyright for this article belongs to the Authors.
Keywords: Magnetic fields; Spectroscopic analysis; Stars, Be Stars; Chemically peculiar-stars; High-resolution spectroscopy; Magnetic-field; Spectroscopic; Star: activity; Stars: Be; Stars: binaries; Stars: chemically peculiar; Techniques: photometric, Photometry
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 30 Jun 2022 05:31
Last Modified: 30 Jun 2022 05:31
URI: https://eprints.iisc.ac.in/id/eprint/73791

Actions (login required)

View Item View Item