Astronomy tower of the Sorbonne

Rising above the rooftops of Paris's Latin Quarter, the Astronomy Tower of the Sorbonne has topped the university's main building since the 1900s, hiding a working telescope inside its dome.

About the Astronomy tower of the Sorbonne

Built between 1885 and 1901 during the reconstruction of the Sorbonne, the 39-metre tower was designed to give the university's students an observatory of their own. It has an upper and a lower dome joined by several rooms and a long staircase, and today it is looked after by the Société astronomique de France (SAF), the country's national amateur astronomy society.

Telescopes & research

The upper dome, visible from the Rue Saint-Jacques below, houses a refracting telescope with a 153mm aperture and a 2,300mm focal length. The lower dome once held a meridian circle and today serves as a workshop where amateurs learn to grind and polish their own telescope mirrors.

Location & getting there

The tower stands on the Sorbonne's historic campus in central Paris, France, in the heart of the Latin Quarter, within easy walking distance of the Panthéon and the Luxembourg Gardens.

Visiting the tower

The SAF runs small guided evenings a couple of times a week, taking groups of around five visitors up the tower's staircase to see the historic telescope and, weather permitting, the night sky itself; on cloudy nights, volunteer guides still cover the building's history and instruments. Because space is limited, visits must be booked in advance through the SAF.

See your named star from here

If you've named a star with Star Register, its coordinates can be found in the star catalogue and shared with an observatory like this one, where a telescope can be pointed toward the exact right ascension and declination.