# Determine sidereal time at the time of sunrise, the highest altitude and azimuth of the rise of Sirius (a B. Psa) in St. Petersburg Let’s construct a celestial sphere for St. Petersburg, knowing that the latitude of the city is 60о north. Let us write down the right ascension and declination of Sirius from the table: a = 7h, b = –17o.
For this declination, let’s draw the celestial parallel of the star KL. Draw the declination circle KRP through the Sirius rising point (point K) and the pole of the world P. Then, from the drawing, the hour angle of Sirius at the moment of Sirius rise will be determined by eye as follows: t = NEQR = 20h (approximately)
From here, at the moment of Sirius rise, it will be: sidereal time
s = t + a = 20h + 7 = 27h or 3h. That is, sidereal time at the time of the rising of Sirius in St. Petersburg is equal to 3 hours.
The highest height of Sirius will be: h = NSL = 30o – 17o = 13o. The azimuth of Sirius rise will be: A = NSK = 60o East. Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.