On what day of the year was the observation carried out in Novosibirsk (φ = 55 °), if the midday height of the Sun was 32 ° 15 ‘?

90 – φ – declination of the Sun = 32 ° 15 ‘
90 – 55 – declination of the Sun = 32 ° 15 ‘
90 – 55 – 32 ° 15 ‘= Sun declination
2 ° 45 ‘= Sun declination.
The minimum value of the noon height of the Sun in Novosibirsk is 90 ° – 55 ° – 23.5 ° = 11.5 °
The noon height of the Sun in Novosibirsk on the day of the equinox is 90 ° – 55 ° = 35 °
Therefore, when the Sun’s midday altitude is 32 ° 15 ‘, declination will be negative. Those. on this day the Sun is located in the southern hemisphere
23.5 ° corresponds to 1410 arc minutes
The sun moves 1410 arc minutes in 93 days
The sun moves 15 arc minutes in 1 day. 2 ° 45 ‘corresponds to 165’. The Sun needs 11 days to move 2 ° 45 ‘. Consequently, the Sun is 11 days away from the autumnal equinox. 23.09 – 11 days = 12.09.
Therefore, observations in Novosibirsk were carried out on September 12