TITLE:   GCN CIRCULAR
NUMBER:  34078
SUBJECT: ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
DATE:    23/06/25 08:21:06 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. Moskvitin (SAO RAS), O. Spiridonova (SAO RAS), S. Belkin (IKI RAS,
HSE), A. Pozanenko (IKI RAS), report on behalf of a larger
collaboration.

We observed the field of the fast red optical transient
ZTF23aaoohpy/AT2023lcr (Swain et al., GCN 34022) with the 1-m
telescope of SAO RAS Zeiss-1000/CCD-photometer on June, 22 and 23. We
have obtained 10 x 300 sec in Rc band during each night.

The OT (Swain et al., GCN 34022; Gompertz et al., GCN 34023; Kumar et
al., GCN 34025; Adami et al., GCN 34030; Perley et al., GCN 34031;
Jiang et al., GCN 34040; Perley et al., GCN 34041; Fulton et al., GCN
34042; Chen et al., GCN 34043, Belkin et al., GCN 34047; Breeveld, GCN
34049; Leonini et al., GCN 34052; Moskvitin et al., GCN 34060, Belkin
et al., GCN 34077) is clearly detected in the stacked frames.
Preliminary results are as following.

Date        UT-start  MJD_mid      t-T0     R_mag
2023-06-22  22:43:06  60117.96396  4.68865  21.68 +/- 0.14
2023-06-23  21:14:21  60118.91196  5.63665  22.12 +/- 0.08

Photometry is based on stars mentioned in Belkin et al.(GCN 34047,
34077) and Moskvitin et al. (GCN 34060). t-T0 is given in days after
the ZTF discovery (Swain et al., GCN 34022).

The light curve of the source has a shallow decay at least between
MJD=60616 and MJD=60618, and then the decay becomes significantly
steeper between MJD=60618 and MJD=60619.