Report on Sky Brightness, Seeing, and Weather Measurements at Timau Observatory, East Nusa Tenggara

Abstract

In 2015, a joint collaboration project to build a new observatory in Mount Timau, East Nusa Tenggara was initiated between LAPAN, ITB, UNDANA, Kupang Regency and East Nusa Tenggara governments. The site selection is based on preliminary studies conducted on nearby location. This paper presents in situ measurements report on seeing, weather and sky brightness obtained on July 2018 using Differential Image Motion Monitor (DIMM) with 20 cm-telescope, Davis Vantage Vue automatic weather station, and Sky Quality Meter, respectively. Despite the high humidity and foggy condition on the afternoon, the site has good seeing condition with median of 0.93 arcsecond and sky brightness around 22.18 magnitude per arcsecond square after midnight.