2018PASP..130a5001V

We report on the design and first year of operations of the DEdicated MONitor of EXotransits and Transients (DEMONEXT). DEMONEXT is a 20-inch (0.5-m) robotic telescope using a PlaneWave CDK20 telescope on a Mathis instruments MI-750/1000 fork mount. DEMONEXT is equipped with a 2048 x 2048 pixel Finger Lakes Instruments (FLI) detector; a 10-position filter wheel with an electronic focuser and B, V, R, and I, g^′ , r ′^ , i^′ , z ′^ ; and clear filters. DEMONEXT operates in a continuous observing mode and achieves 2-4 mmag raw, unbinned, precision on bright V 13 targets with 20-120 second exposures, and 1 mmag precision achieved by binning on 5-6 minute timescales. DEMONEXT maintains sub-pixel ( 0.5 pixels) target position stability on the CCD over 8 hours in good observing conditions, with degraded performance in poor weather ( 1 pixel). DEMONEXT achieves 1%-10% photometry on single-epoch targets with V 17 in 5 minute exposures, with detection thresholds of V~21. The DEMONEXT automated software has produced 143 planetary candidate transit light curves for the KELT collaboration and 48 supernovae and transient light curves for the ASAS-SN supernovae group in the first year of operation. DEMONEXT has also observed for a number of ancillary science projects including Galactic microlensing, active galactic nuclei, stellar variability, and stellar rotation.