ATLAS23dmk: most likely WZ Sge, still showing superhumps now?
The light curve resembles a WZ Sge star. The spectrum excludes a nova (also with a similar light curve). This object may still be in a late phase of the plateau and may be still showing superhumps (still less than 50 d after the peak).
YYYYMMDD(UT) mag observer 20230312.2850 14.896o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.2894 14.886o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.2949 14.902o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.2967 14.934o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.3009 14.962o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.3072 14.959o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.3077 14.973o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230312.3178 14.997o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230313.4554 15.75C (Masayuki Moriyama) 20230314.5085 16.22C (Masayuki Moriyama) 20230314.5103 15.94B (Masayuki Moriyama) 20230314.5134 15.74Rc (Masayuki Moriyama) 20230314.5136 <15.04Ic (Masayuki Moriyama) 20230314.5146 15.97V (Masayuki Moriyama) 20230315.6207 16.48C (Masayuki Moriyama) 20230315.6256 15.72B (Masayuki Moriyama) 20230315.6301 16.19V (Masayuki Moriyama) 20230316.3178 16.310o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230316.3214 16.401o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230316.3313 16.487o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230316.3380 16.469o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230318.4729 16.60C (Masayuki Moriyama) 20230319.5440 167:C (Masayuki Moriyama) 20230326.4765 <169C (Masayuki Moriyama) 20230328.2353 17.616o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230328.2396 17.624o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230328.2448 17.504o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230328.2548 17.539o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230331.4957 173C (Masayuki Moriyama) 20230401.6107 <160C (Masayuki Moriyama) 20230410.2483 18.187o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230410.2516 18.149o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230410.2688 17.944o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230410.2943 18.071o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230412.2411 18.058c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230412.2472 18.273c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230412.2500 18.127c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230412.2602 18.325c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230414.2400 18.319c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230414.2439 18.245c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230414.2491 18.136c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230414.2594 18.283c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230416.2418 18.320c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230416.2485 18.244c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230416.2534 18.362c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230416.2637 18.332c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230422.2362 18.746c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230422.2394 18.312c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230422.2470 18.424c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230422.2638 18.500c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505))