@article{639e34127eeb4a63b9f08361f0f9a4b6,
title = "Light and colour variations of mira variables in the small magellanic cloud",
abstract = "The goal of this paper is to characterize the light variation properties of Mira variables in the Small Magellanic Cloud. We have investigated a combined optical and near-infrared multi-epoch data set of Mira variables based on our monitoring data obtained over 15 yr. Bolometric correction relations are formulated for various near-infrared colours. We find that the same bolometric correction equation holds for both the bolometricly brightest and faintest pulsation phases. Period–bolometric magnitude relations and period–colour relations were derived using time-averaged values. Phase lags between bolometric phase and optical and near-infrared phases were detected from the O-rich (the surface C/O number ratio is below unity) Mira variables, while no significant systematic lags were observed in most of the C-rich (the C/O ratio is over unity) ones. Some Miras show colour phase inversions, e.g. H–Ks at its bluest while J–H and J–Ks are at their reddest values at about the bolometricly brightest phase. Their occurrence conditions were studied but no clear direct or indirect trigger was found. A large NIR colour change unassociated with stellar pulsation was observed in Miras with long secondary periods, and its possible explanation is described.",
keywords = "Infrared: stars, Stars: AGB and post-AGB, Stars: carbon, Stars: late-type",
author = "Yoshifusa Ita and Menzies, {John W.} and Whitelock, {Patricia A.} and Noriyuki Matsunaga and Masaki Takayama and Yoshikazu Nakada and Toshihiko Tanab{\'e} and Feast, {Michael W.} and Takahiro Nagayama",
note = "Funding Information: We thank the anonymous reviewers for their careful reading and their insightful comments and suggestions for improving this paper. This work is partly supported by the Grant-in-Aid for Scientific Research (C) No.18K03690 and (A) No.16H02158 and Grant-in-Aid for Encouragement of Young Scientists (B) No.21740142 from the Ministry of Education, Culture, Sports, Science and Technology of Japan. This work is also partly supported by the Brain Circulation Program (R2301) by Japan Society for the Promotion of Science (JSPS). This paper uses observations made at the South African Astronomical Observatory. PAW and JWM acknowledge support from the South African National Research Foundation (NRF). We appreciate the support for our collaboration, in 2015–2017, provided by the Joint Research Project under agreement between the JSPS and NRF. Publisher Copyright: {\textcopyright} 2021 Oxford University Press. All rights reserved.",
year = "2021",
month = jan,
day = "1",
doi = "10.1093/mnras/staa3251",
language = "English",
volume = "500",
pages = "82--100",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}