Photometric Study of a Distant SU UMa-type Dwarf Nova KSP-OT-201803a

@misc{kim2026photometric,
  title = {{Photometric Study of a Distant SU UMa-type Dwarf Nova KSP-OT-201803a}},
  author = {Sang Chul Kim and Youngdae Lee and Dae-Sik Moon and Hong Soo Park and Dong Wook Kim},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.05833},
  eprint = {2611.05833},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.05833},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Photometric Study of a Distant SU UMa-type Dwarf Nova KSP-OT-201803a
AU  - Sang Chul Kim
AU  - Youngdae Lee
AU  - Dae-Sik Moon
AU  - Hong Soo Park
AU  - Dong Wook Kim
PY  - 2026
DA  - 2026/11/04
PB  - arXiv
DO  - 10.48550/arxiv.2611.05833
UR  - https://arxiv.org/abs/2611.05833
AB  - We present the discovery and photometric study of a distant dwarf nova KSP-OT-201803a using BVI-band observation data obtained by using the KMTNet Supernova Program. One superoutburst (SO) and three normal outbursts are identified from two years of observations (2018-2019), which show that KSP-OT-201803a is an SU UMa-type dwarf nova (DN). Applying the phase dispersion minimization method to the superhump data during the plateau phase of the SO yields a superhump period of P_sh = 127.4 minutes (=2.123 hr =0.08847 days). By stacking ten images of the quiescent phase, we find the quiescent phase magnitude of V = 22.59 +/- 0.18 mag. The SO shows quiescent-to-peak amplitude of 4.97 +/- 0.18 mag and duration of 16.59 days which are typical for the SU UMa-type DNe. Using the superhump period-orbital period relation of SU UMa stars, we obtain the approximate distance of 3.7 +/- 0.3 kpc to KSP-OT-201803a and Galactocentric distance of 9.4 kpc and height from the Galactic plane of +1.2 kpc. Stars at these large distances may belong to the Galactic halo or thick disk, which contain old, metal-poor Population II stars; therefore, these systems may have undergone a different evolutionary process than Population I objects. The orbital period gap of DNe spans 2.45-3.18 hours. Assuming that the orbital period of KSP-OT-201803a is a few percent shorter than its superhump period, KSP-OT-201803a may have just emerged from the period gap and recently resumed mass transfer after crossing its lower boundary.
ER  -