ASASSN-24ah: new SU UMa (or WZ Sge) star, rebrightening and superhumps

This object showed a dip and rebrightening.

YYYYMMDD(UT) mag observer 20240115.6584 14.67C (Masayuki Moriyama) 20240119.5520 14.97C (Masayuki Moriyama) 20240121.7547 <151C (Masayuki Moriyama) 20240121.8954 <173C (Masao Funada) 20240122.8613 <174C (Masao Funada) 20240124.5826 14.95C (Masayuki Moriyama) 20240125.5979 14.85C (Masayuki Moriyama)

Observations by Tamas Tordai on Jan. 25-26 showed superhumps with a period of 0.0602(4) d and an amplitude of 0.11 mag. The object was rising on Jan. 24 in Tordai's observations.

Superhumps were not apparent in observations by Itoh-san before this dip. The plateau-like phase before the dip was long enough, likely excluding a short precursor in an ordinary SU UMa star. This object may be a WZ Sge star in which early superhumps were below the detection limit during the initial outburst. The superhump period suggests a system with multiple rebrightenings if this interpretation is correct.