Contemplating celestial bodies is an ancient activity, applied in sectors such as agriculture, naval guidance and time measurement. The instrument known as a celestial chart works like a diagram of the firmament at night, outlining the position of stars, stellar groupings and galaxies, being adjusted to a specific date, time and geographic point.
This map of the cosmos serves to help understand the visible elements in the sky, acting as a true roadmap through the universe. Its application is accessible to anyone interested in deepening knowledge about stars and constellations, without the need to purchase expensive or complex devices.
First steps to using the star guide
To start, it is essential to use a celestial chart that corresponds to your location and the exact period, generally indicated by digital tools, as the arrangement of the stars changes continuously. Once you have the map in hand, follow these guidelines:
- Position yourself towards the south cardinal point;
- Lift your celestial map towards the sky, making the “South” marking on the paper coincide with the true south direction;
- Find references in known star formations, such as the Southern Cross, Orion’s Belt, or identify a planet that is bright at that moment.
After this initial step, navigation through the firmament becomes more intuitive, making it easier to identify other constellations. Astronomer Eugênio Reis, from the Museum of Astronomy and Related Sciences (Mast), emphasizes the ideal conditions for observation with the help of the celestial chart, highlighting the growing accessibility of amateur astronomy: “Look for a place with little or no light pollution, with a clear sky without clouds and an unobstructed horizon, preferably, to help with visualization.” The popularization of applications and online resources further democratizes this ancient practice.
Every month, Mast, a research institution linked to the Ministry of Science, Technology and Innovation (MCTI) and located in Rio de Janeiro (RJ), provides its own version of the celestial chart destined for the capital of Rio de Janeiro. Furthermore, it is easy to obtain or consult personalized star maps for any region and period through applications and digital platforms.

