The Sejong Open Cluster Survey (SOS). VII. A Photometric Study of the
  Young Open Cluster IC 1590
  Young open clusters are ideal laboratories to understand star formation
process. We present deep UBV I and Halpha photometry for the young open cluster
IC 1590 in the center of the H II region NGC 281. Early-type members are
selected from UBV photometric diagrams, and low-mass pre-main sequence (PMS)
members are identified by using Halpha photometry. In addition, the published
X-ray source list and Gaia astrometric data are also used to isolate probable
members. A total of 408 stars are selected as members. The mean reddening
obtained from early-type members is <E(B-V) = 0.40 +/- 0.06 (s.d.). We confirm
the abnormal extinction law for the intracluster medium. The distance modulus
to the cluster determined from the zero-age main-sequence fitting method is
12.3 +/- 0.2 mag (d = 2.88 +/- 0.28 kpc), which is consistent with the distance
d = 2.70 ^+0.24 _-0.20 kpc from the recent Gaia parallaxes. We also estimate
the ages and masses of individual members by means of stellar evolutionary
models. The mode of the age of PMS stars is about 0.8 Myr. The initial mass
function of IC 1590 is derived. It appears a steeper shape (Gamma = -1.49 +/-
0.14) than that of the Salpeter/Kroupa initial mass function for the high mass
regime (m > 1 M_sun). The signature of mass segregation is detected from the
difference in the slopes of the initial mass functions for the inner (r < 2.'5)
and outer region of this cluster. We finally discuss the star formation history
in NGC 281.
