Eclipsing binaries offer a unique opportunity to determine basic stellar properties .
With the advent of wide-field camera and all-sky time-domain surveys , thousands of eclipsing binaries have been charted via light curve classification , yet their fundamental properties remain unexplored , mainly due to the extensive efforts needed for spectroscopic follow-ups .
In this paper we present the discovery of a short period ( P=0.313 days ) double-lined M-dwarf eclipsing binary , CSSJ114804.3+255132/SDSSJ114804.35+255132.6 , by cross-matching binary light curves from Catalina Sky Surveys and spectroscopically classified M dwarfs from Sloan Digital Sky Survey .
We obtain follow-up spectra using Gemini telescope , enabling us to determine the mass , radius , and temperature of the primary and secondary component to be M _ { 1 } = 0.47 \pm 0.03 ( statistic ) \pm 0.03 ( systematic ) M _ { \odot } , M _ { 2 } = 0.46 \pm 0.03 ( statistic ) \pm 0.03 ( systematic ) M _ { \odot } , R _ { 1 } = 0.52 \pm 0.08 ( statistic ) \pm 0.07 ( systematic ) R _ { \odot } , R _ { 2 } = 0.60 \pm 0.08 ( statistic ) \pm 0.08 ( systematic ) R _ { \odot } , T _ { 1 } = 3560 \pm 100 K , and T _ { 2 } = 3040 \pm 100 K , respectively .
The systematic error was estimated using the difference between eccentric and non-eccentric fit .
Our analysis also indicates that there is definitively 3rd-light contamination ( 66 % ) in the CSS photometry .
The secondary star seems inflated , probably due to tidal locking of the close secondary companion , which is common for very short period binary systems .
Future spectroscopic observations with high resolution will narrow down the uncertainties of stellar parameters for both component , rendering this system as a benchmark in studying fundamental properties of M dwarfs .