| Full text | |
| Author(s): |
Araujo, Alexandre
;
Valio, Adriana
Total Authors: 2
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 522, n. 1, p. 5-pg., 2023-06-01. |
| Abstract | |
How do the characteristics of starspots influence the triggering of stellar flares? Here, we investigate the activity of two K-type stars, similar in every way from mass to rotation periods and planetary systems. Both stars exhibit about a hundred spots; however, Kepler-411 produced 65 superflares, while Kepler-210 presented none. The spots of both stars were characterized using the planetary transit mapping technique, which yields the intensity, temperature, and radius of starspots. The average radius was (17 +/- 7) x10(3) and (58 +/- 23) x10(3) km, while the intensity ratio with respect to the photosphere was (0.35 +/- 0.24) and (0.64 +/- 0.15) I-c, and the temperature was (3800 +/- 700) and (4180 +/- 240) K for spots of Kepler-411 and Kepler-210, respectively. Therefore, spots on the star with no superflares, Kepler-210, are mostly larger, less dark, and warmer than those on the flaring star, Kepler-411. This may be an indication of magnetic fields with smaller magnitude and complexity of the spots on Kepler-210 when compared to those on Kepler-411. Thus, starspot area appears not to be the main culprit of superflares triggering. Perhaps the magnetic complexity of active regions is more important. (AU) | |
| FAPESP's process: | 13/10559-5 - Investigation of high energy and plasma astrophysics phenomena: theory, numerical simulations, observations, and instrument development for the Cherenkov Telescope Array (CTA) |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Special Projects |