Jian M., Gao S., Zhao H. & Jiang B.

Abstract: Intrinsic colors of normal stars are derived in the popularly used infrared bands involving the Two Micron All-Sky Survey/JHK_S, Wide-field Infrared Survey Explorer, Spitzer/IRAC, and AKARI/S9W filters. Based on three spectroscopic surveys—LAMOST, RAVE, and APOGEE, stars are classified into groups of giants and dwarfs, as well as metal-normal and metal-poor stars. An empirical analytical relation of the intrinsic color is obtained with stellar effective temperature {T}_{eff} for each group of stars after the zero-reddening stars are selected from the blue edge in the J-λ versus {T}_{eff} diagram. It is found that metallicity has little effect on the infrared colors. In the near-infrared bands, our results agree with previous work. In addition, the color indexes H-W2 and {K}_S-W1, which are taken as constant to calculate interstellar extinction, are discussed. The intrinsic colors of M-type stars are derived separately due to the lack of accurate measurement of their effective temperature.

                                                                                          AJ, 2017, 153, 5