4.1.1. General Properties and Multi-Wavelength Observations

The BAT prompt spectrum (*T*<sup>90</sup> = 0.48 s) is well described by a power-law with index *α* = −0.11 ± 0.88 and an exponential high-energy cutoff, corresponding to a peak energy with *E<sup>p</sup>* = 46.3 ± 6.4 keV [143]. The GBM prompt spectrum (*T*<sup>90</sup> = 1.088 ± 0.977 s) is fitted with a cutoff power-law function as well, with *E<sup>p</sup>* = 92 ± 28 keV. Being located at redshift *z* = 0.162, this is one of the nearest short GRBs detected up to date. Its isotropic-equivalent energy *<sup>E</sup>γ*,*iso* <sup>∼</sup> 1.2 <sup>×</sup> <sup>10</sup><sup>49</sup> erg is toward the low energy edge of the known distribution for short GRBs [144]).

Afterglow observations are available in the radio, optical, X-ray and (V)HE band. Fermi-LAT observations were performed from the trigger time up to 2315 s and from 5285 s to 8050 s, and did not reveal any significant excess in the 0.3–3 GeV band [145]. Swift-XRT observations [146] started 57 s after the trigger time and revealed a complex behavior of the X-ray afterglow light curve. An initial plateau is followed by a steep decay at around 10<sup>2</sup> s. Then, a power-law decay with index ∼−0.8 is observed after <sup>∼</sup>10<sup>3</sup> s [147,148]. Optical observations were performed by several instruments [149–152], revealing the presence of a fading source with a magnitude *r* = 22.6 ± 0.1 mag 0.95 h after *T*0. The identification of the host galaxy allowed the measurement of the spectroscopic redshift *z* = 0.162. The GRB is located in the outskirts of the host spiral galaxy, at ∼15 kpc projected distance from its center [148,153]. A fading radio afterglow counterpart was observed at 6 GHz by VLA starting from 3.6 h after the burst trigger [154].
