GJ 3236: An active red-dwarf eclipsing binary system

• Published in: New astronomy 2022-10, Vol.96, p.101831, Article 101831
• Main Authors: Zhang, B., Qian, S.-B., Zhi, Q.-J., Dong, A.-J., Zhu, L.-Y.
• Format: Article
• Language: English
• Subjects: Eclipsing binary; Flares; Magnetic activity cycle; Red dwarf
• ISSN: 1384-1076; 1384-1092
• DOI: 10.1016/j.newast.2022.101831

GJ 3236 is a low-mass red-dwarf eclipsing binary (EB) with two M4V components. In this paper, new photometric light curves (LCs) of GJ 3236 are presented and analyzed by using the 2013 version of the Wilson–Devinney (W–D) code. Our photometric solutions suggest that GJ 3236 is an active detached EB system with strong magnetic field. Since 2009, we have monitored this target more than 10 years and obtained 22 mid-eclipse times with high precision. By using the O–C method, we revised its period as 0.7712562 days. According to Applegate mechanism, the O–C diagram of GJ 3236 should show a quasi-periodic variation, however, it does not now. Based on these, we thought that it is possible evolved through the accretion of circumstellar matter. Besides, both of components of GJ 3236 present a similar radius inflation, which could be explained by the strong magnetic activity. •The first light curves of GJ 3236 in B, V, RC and IC bands are obtained and analyzed.•It is found that GJ3236 is a detached red-dwarf eclipsing binary with a strong magnetic field.•GJ 3236 is possible evolved through the accretion of circumstellar matter.