Observations

Observing conditions in Ondřejov

The observing conditions are given by the location of Ondřejov in the middle Europe. The typical seeing is about 3 arcseconds and only rarely falls below 2 arcseconds. The distribution of observing time through the year 2020 can be seen in following figure. The winter months are usually very poor regarding the observing nights, while March-April and June-September are the months with the highest percentage of usable observing time.

Distribution of observing hours for 2021. The grey-shaded columns (with numbers in white) show for each month the total amount of hours available for observations (when the Sun is 12 degrees below the horizon). Blue columns and corresponding numbers in yellow boxes show the number of used observing hours (shutter open time of scientific targets together for all available devices – 700 and OES spectrographs, and photometric CCD camera). The numbers in the green boxes represent the percentage of actually used observing hours. Credit: P. Škoda, 2021

Observation statistics

Graphs lower on the page show distribution of observing hours in last nine years. The grey-shaded columns (with numbers in white) show for each month the total amount of hours available for observations (when the Sun is 12 degrees below the horizon). Blue columns and corresponding numbers in yellow boxes show the number of used observing hours (camera shutter open time of scientific targets together for all available devices – 700 and OES spectrographs and since 2019 also photometric CCD camera; calibrations are excluded). The numbers in the green boxes represent the percentage of actually used observing hours.

2020
2019 (Sep.-Dec., technical shutdown)
2018
2017 (Jan.-Feb., technical shutdown)
2016 (Apr.-Dec., technical shutdown)
2015
2014
2013
2012

Older statistical data in the same graphical form are also available (value ‘0’ is in most of the cases due a technical shutdown):

Monitoring of meteorological conditions

Weather monitor: Meteostation

Sky monitor: AllSky