TITLE: GCN CIRCULAR NUMBER: 29330 SUBJECT: ZTF21aaeyldq: GROND observations DATE: 21/01/19 16:38:42 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu (TLS Tautenburg), A. Rau (MPE Garching), and S. Klose (TLS Tautenburg) report: We observed the field of ZTF21aaeyldq/AT2021any (Ho et al., GCN 29305) with GROND mounted at the 2.2m MPG telescope at the ESO La Silla Observatory (Chile). Observations were performed during three epochs. The data were calibrated against SDSS stars in the field. In the g' band we measure the following AB magnitudes: dt/days mag 1.82415 23.39 +/- 0.11 2.02104 23.47 +/- 0.06 2.87115 23.84 +/- 0.09. Following Kann et al. (GCN 29321), here we assumed a GRB trigger time 22 minutes before the discovery image (Ho et al., GCN 29305), i.e., at JD 2459230.77622. Based on these three epochs, we measure a decay slope of 0.94 +/- 0.05, in agreement with Kann et al. (GCN 29321). There is no evidence for an underlying host galaxy. The transient was not detected in the NIR bands. We thank Sam Kim (PUC) for performing the observations and all people, in particular P. Eigenthaler, R. Lechaume, A. Hempel, M. Hempel, T. Schweyer, A. González, involved in bringing GROND back online after its shutdown due to the Covid 19 pandemia in early 2020.