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New CCD photometry of seven successive years from 2010 is presented for theHW Vir-type eclipsing binary 2M 1533+3759. Using the $VI$ light curves togetherwith the radial-velocity data given by For et al. (2010), we determined theabsolute parameters of each component to be $M_1$ = 0.442$\pm$0.012 M$_\odot$,$M_2$ = 0.124$\pm$0.005 M$_\odot$, $R_1$ = 0.172$\pm$0.002 R$_\odot$, $R_2$ =0.157$\pm$0.002 R$_\odot$, $L_1$ = 19.4$\pm$1.4 L$_\odot$, and $L_2$ =0.002$\pm$0.002 L$_\odot$. These indicate that 2M 1533+3759 is a detachedsystem consisting of a normal sdB primary and an M7 dwarf companion. Detailedanalyses of 377 minimum epochs, including our 111 timings, showed that theorbital period of the system remains constant during the past 12 yrs.Inspecting both types of minima, we found a delay of 3.9$\pm$1.0 s in thearrival times of the secondary eclipses relative to the primary eclipse times.This delay is in satisfactory agreement with the predicted R{\o}mer delay of2.7$\pm$1.4 s and the result is the second measurement in sdB+M eclipsingbinaries. The time shift of the secondary eclipse can be explained by somecombination of the R{\o}mer delay and a non-zero eccentricity. Then, the binarystar would have a very small eccentricity of $e \cos {\omega} \simeq$ 0.0001.

Long-term CCD Photometry and Physical Properties of the sdB+M Eclipsing System 2M 1533+3759