1304 Arosa asteroid is yet another main belt object that orbits the Sun in 5 years and 9 months. Arosa diameter is estimated to 40km, and it is actually pretty faint – apparent magnitude is about 14 mag. It was discovered in 1928, and its name comes from Swiss mountain village Arosa. This asteroid is a good target for amateur photometry due to its fast rotation period.
Last two nights were actually first nights this year I was able to plan some observations and also complete them 🙂 Conditions were not perfect, transparency was poor due to high clouds presence, so photometry data quality is not high plus at current orientation amplitude of changes is about 0.1mag. Nevertheless I was able to collect about 5 hours of exposures that is about 2/3 of asteroid rotational period. At that time Arosa was moving near border between Ursa Major and Leo constellations. During 5 hours it travelled about 315,000 km.
I used Muniwin software to perform actual photometry. Muniwin has a nice feature that can follow moving photometry targets automatically. You just need to select two or more key frames, and all positions will be calculated upon them.
Technical data: Date: 26.02.2019 Location: Nieborowice, Poland Telescope: Meade ACF 10" Corrector: AP CCDT67 Camera: QHY163M, gain 100 Mount: SW EQ6 Guiding: SW 80/400 + ASI290MM Exposures: 150 x 120s, L filter Conditions: suburban sky, seeing good, transparency poor Reference star: UCAC4-604-048321 (13.92mag)