■ [unidentified] J1509-21: fading continues with a reddening trend
The nature of the object is still unknown. It keeps fading, with a clear reddening trend. The average fading rate remains almost constant at 0.05 mag/day. The raddening rate of V-J can be calculated to be +0.17/day. At quiescence, the object is V=11.229 (Tycho-2), J=10.536(2MASS), and hence, V-J=0.693. If the fading and reddening rates are constant, the object returned to the quiescent level within two weeks.