The sejong open cluster survey (sos). IV. the young open clusters ngc 1624 and NGC 1931

Beomdu Lim*, Hwankyung Sung, Michael S. Bessell, Jinyoung S. Kim, Hyeonoh Hur, Byeong Gon Park

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    17 Citations (Scopus)


    Young open clusters located in the outer Galaxy provide us with an opportunity to study star formation activity in a different environment from the solar neighborhood. We present a UBVI and Hphotometric study of the young open clusters NGC 1624 and NGC 1931 that are situated toward the Galactic anticenter. Various photometric diagrams are used to select the members of the clusters and to determine the fundamental parameters. NGC 1624 and NGC 1931 are, on average, reddened by = 0.92 ± 0.05 and 0.74 ± 0.17 mag, respectively. The properties of the reddening toward NGC 1931 indicate an abnormal reddening law ( = 5.2 ± 0.3). Using the zero-age main sequence fitting method we confirm that NGC 1624 is 6.0 ± 0.6 kpc away from the Sun, whereas NGC 1931 is at a distance of 2.3 ± 0.2 kpc. The results from isochrone fitting in the Hertzsprung-Russell diagram indicate the ages of NGC 1624 and NGC 1931 to be less than 4 and 1.5-2.0 Myr, respectively. We derived the initial mass function (IMF) of the clusters. The slope of the IMF ( = -2.0 ± 0.2 and = -2.0 ± 0.1) appears to be steeper than that of the Salpeter/Kroupa IMF. We discuss the implication of the derived IMF based on simple Monte-Carlo simulations and conclude that the property of star formation in the clusters does not seem to be significantly different from that in the solar neighborhood.

    Original languageEnglish
    Article number127
    JournalAstronomical Journal
    Issue number4
    Publication statusPublished - 1 Apr 2015


    Dive into the research topics of 'The sejong open cluster survey (sos). IV. the young open clusters ngc 1624 and NGC 1931'. Together they form a unique fingerprint.

    Cite this