Principles of visual key construction―with a visual identification key to the Fagaceae of the southeastern United States

We present the first visual, as opposed to illustrated, keys to a group of taxa. The creation of four visual keys to the Fagaceae of the southeastern United States are described, one for each of the following characteristics: leaves, buds, fruits, bark

Image use in field guides and identification keys: review and recommendations

We review image use in field guides and keys, and formulate a set of best practices for image use. The review covers the full range of guides, from those that consist only of species descriptions, to lavishly illustrated technical guides

K2 Targets Observed with SPHERE/VLT:An M4-7 Dwarf Companion Resolved around EPIC 206011496

The quest to discover exoplanets is one of the most important missions in astrophysics, and is widely performed using the transit method, which allows for the detection of exoplanets down to the size of Mercury. However, to confirm these detections, additional vetting is mandatory. We selected six K2 targets from campaigns #1 to #8 that show transit light curves corresponding to Earth-sized to Neptune-sized exoplanets. We aim to discard some scenarios that could mimic an exoplanetary transit, leading to a misinterpretation of the data. We performed direct imaging observations using the SPHERE/VLT instrument to probe the close environment of these stars. For five of the K2 targets, we report no detection and we give the detection limits. For EPIC 206011496, we detect a 0.38 $\pm$ 0.06 $M_{\odot}$ companion at a separation of 977.12 $\pm$ 0.73 mas (140.19 $\pm$ 0.11 au). The spectral analysis corresponds to an M4-7 star, and the analysis of the proper motion shows that it is bounded to the primary star. EPIC 206011496 also hosts an Earth-like planetary candidate. If it transits the primary star, its radius is consistent with that of a super-Earth. However, if it transits the companion star, it falls into the mini-Neptune regime.Comment: 10 pages, 5 figures, 4 tables. Published in the Astronomical Journal. This version includes the editing correction