TITLE:   GCN CIRCULAR
NUMBER:  29327
SUBJECT: ZTF21aaeyldq: LBT near-infrared observations
DATE:    21/01/19 13:46:36 GMT
FROM:    Andrea Rossi at INAF  <andrea.rossi@inaf.it>

A. Rossi, E. Palazzi (INAF-OAS) reports on behalf of the GRAWITA 
collaboration:

We observed the field of ZTF21aaeyldq (Ho et al., GCN 29305) 
simultaneously the J and H bands with the LUCI near-infrared imager and 
spectrograph mounted on the Large Binocular Telescope (LBT, Mt Graham, 
AZ, USA). Observations were obtained on 2021-01-17 at the UT 06:35:00 
(midtime), i.e. ~1 day after the first ZTF detection, for a total of 15 
min of on-source exposure time in each band under not very good sky 
conditions (seeing=1.4").

We detect the transient (de Ugarte-Postigo GCN#29307, Kumar et al., GCNs 
#29308; Ahumada et al., GCN #29309; Zhu et al., GCN #29310; Hu et al., 
GCN #29312, Kann et al., GCN #29321) in both J and H-band images, and we 
measure the following AB magnitudes:
J=21.62+-0.20
H=21.36+-0.24
calibrated against 2MASS field stars.

We acknowledge the excellent support from the LBTO and LBT-INAF staff, 
particularly A. Cardwell and D. Paris, in obtaining these observations.