تقرير
Characterization of starspots on a young M-dwarf K2-25: multi-band observations of stellar photometric variability and planetary transits
| العنوان: | Characterization of starspots on a young M-dwarf K2-25: multi-band observations of stellar photometric variability and planetary transits |
|---|---|
| المؤلفون: | Mori, Mayuko, Ikuta, Kai, Fukui, Akihiko, Narita, Norio, de Leon, Jerome P., Livingston, John H., Ikoma, Masahiro, Kawai, Yugo, Kawauchi, Kiyoe, Murgas, Felipe, Palle, Enric, Parviainen, Hannu, Rodríguez, Gareb Fernández, Terada, Yuka, Watanabe, Noriharu, Tamura, Motohide |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | Detailed atmospheric characterization of exoplanets by transmission spectroscopy requires careful consideration of stellar surface inhomogeneities induced by starspots. This effect is particularly problematic for planetary systems around M-dwarfs, and their spot properties are not fully understood. We investigated the stellar activity of the young M-dwarf K2-25 and its effect on transit observations of the sub-Neptune K2-25b. From multi-band monitoring observations of stellar brightness variability using ground-based telescopes and TESS, we found that the temperature difference between the spots and photosphere is <190 K and the spot covering fraction is <61% (2$\sigma$). We also investigated the effect of starspot activity using multi-epoch, multi-band transit observations. We rule out cases with extremely low spot temperatures and large spot covering fractions. The results suggest that spots could distort the transmission spectrum of K2-25b by as much as $\sim$100 ppm amplitude, corresponding to the precision of JWST/NIRSPEC of the target. Our study demonstrates that simultaneous multi-band observations with current instruments can constrain the spot properties of M-dwarfs with good enough precision to support atmospheric studies of young M-dwarf planets via transmission spectroscopy. Comment: 24 pages, 24 figures, Accepted for publication in MNRAS |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2403.13946 |
| رقم الأكسشن: | edsarx.2403.13946 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |