Osvaldo dos Santos Barros Mathematician and Researcher at Sebastião Sodré da Gama Pará Planetarium
Constellation of the Southern CrossWirar Kamy, the Crux Crux, the constellation of the Southern Cross, is formed by five stars, but only four compose the segments of the cross. These stars are popularly known as Magalhães (the brightest) the Rubídea (the reddish) forming the longest segment, and Mimosa and Pálida, forming the shortest segment. The Intruder (the least bright) does no belong to the cross' design.If we extend an imaginary line joining Pálida and Mimosa, we will find the stars Alpha and Beta Centauri, known as the sentinels of the Cross and situated in the Milky Way. Alfa Centauri is the brightest star in the sky. These two stars help to locate and identify the constellation of the Southern Cross.
The Tembé Indians observe the position of Wirar Kamy (that's what they call the Crux) in the sky to orient their seasonal activities. As with other Amazonian peoples who live close to the Equator, they identify only two climatic seasons, which correspond to differences in the amount of rainfall. One is winter, when rains are intense and frequent; and the other is summer, or the dry season, when the rains decrease in intensity and frequency. In Amazonia, it is common to hear that the seasons in fact consist of a period when it rains all day long and another period when it rains every day.
For the Tembé, these two periods also imply on different farming activities. During the rainy season, which starts in middle October and extends until middle May, it is time for burning, clearing, seeding and weeding the garden plots. In the following dry months, it is the season of harvesting, followed by a short break until a new planting cycle begins. In the area inhabited by the Tembé, Wirar Kamy is visible in the sky in March, when, at sunset, it is aligned close to the horizon, facing east. This appearance marks the middle of the rainy season, indicating the end of the seeding period. This is a period in between harvests, when the crops yielded from the previous cycle are complete. Also, wild fruits are rare, and the high tides and the heavy rains make game and fish scarce.
With insufficient provisions and the proliferation of tropical diseases (especially malaria, due to increase in number of mosquitoes), this is considered the most difficult time of the year. In June, Wirar Kamy, in the middle of the sky, indicates that the dry period has begun, together with abundance of crops, fish and game. It is also time to thank the gods and to perform initiation rites. That is a time of great prosperity.
In September, the Crux approaches the western horizon, marking the middle of the dry season. It is time for the gardens to rest before a new planting cycle begins, when plots will again guarantee provisions for the following year.