We present JHK near-infrared photometric study for the old open cluster (OC) Trumpler 5 (Tr 5), based on the 2MASS data. From the color-magnitude diagrams of Tr 5, we have located the position of the red giant clump (RGC) stars, and used the mean magnitude of the RGC stars in K-band to estimate the distance to Tr 5, d = 3:1±0:1 kpc ((m-M)0 = 12:46±0:04). From fitting the theoretical isochrones of Padova group, we have estimated the reddening, metallicity, and age : E(B-V ) = 0:64±0:05, [Fe/H] = -0:4 ± 0:1 dex, and t = 2:8 ± 0:2 Gyr (log t = 9:45 ± 0:04), respectively. These parameters generally agree well with those obtained from the previous studies on Tr 5 and confirms that this cluster is an old OC with metallicity being metal-poorer than solar abundance, located in the anti-Galactic center region.

• Sang Chul Kim(Korea Astronomy and Space Science Institute) Corresponding Author
• Jaemann Kyeong(Korea Astronomy and Space Science Institute)
• Eon-Chang Sung(Korea Astronomy and Space Science Institute)