Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other.
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years.The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty.
X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects. X-radiation is absorbed by the Earth's atmosphere , so instruments to detect X-rays must be taken to high altitude by balloons , sounding rockets , and satellites .
Through Islamic astronomy, Indian astronomy had an influence on European astronomy via Arabic translations. During the Latin translations of the 12th century, Muhammad al-Fazari's Great Sindhind (based on the Surya Siddhanta and the works of Brahmagupta), was translated into Latin in 1126 and was influential at the time.
In astronomy, first light is the first use of a telescope (or, in general, a new instrument) to take an astronomical image after it has been constructed. This is often not the first viewing using the telescope; optical tests will probably have been performed to adjust the components.
Sofía (en búlgaro, София) es la capital y la ciudad más grande de la República de Bulgaria.Con una población de 1 269 384 habitantes en 2018, se trata de la 14.ª mayor ciudad de la Unión Europea, donde ingresó en enero del 2007, y alrededor de 1 380 406 en su área metropolitana, la Provincia Capital. 
In astronomy, a planet's elongation is the angular separation between the Sun and the planet, with Earth as the reference point. The greatest elongation of a given inferior planet occurs when this planet's position, in its orbital path around the Sun, is at tangent to the observer on Earth.