Teegarden's star is a late-type M-dwarf planet host, typically showing only rather low levels of activity. In this paper we present an extensive characterisation of this activity at photospheric, chromospheric, and coronal levels. We specifically investigated TESS observations of Teegarden's star, which showed two very large flares with an

Aims. We used the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2) photometry in 12 optical bands over 2176 deg 2 to estimate the fraction of white dwarfs with the presence of Ca II H+K absorption along the cooling sequence. Methods. We compared the J-PLUS photometry against metal-free theoretical models to estimate

Context. With its 12 optical filters, the Javalambre-Photometric Local Universe Survey (J-PLUS) provides an unprecedented multicolor view of the local Universe. The third data release (DR3) covers 3192 deg 2 and contains 47.4 million objects. However, the classification algorithms currently implemented in the J-PLUS pipeline are deterministic and