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ALMA Construction Site -Part 2-

This time, I will show you the night sky over the ALMA Operations Support Facility. Most famous celestial objects in the southern hemisphere are the Southern Cross and Large and Small Magellanic Clouds. In Photo 1, you can see the Southern Cross lying on its side around the center of the Milky Way, and in the lower region, there is a dark cloud, so-called “Coalsack.” The tower shown in the right has a transmitter on its top to measure the antenna surface accuracy with a method called “radio holography.” The Large Magellanic Cloud is in the upper left region of the tower, and the Small Magellanic Cloud is in the left side of the middle part of the tower. These clouds look blurred unlike stars, so an easier way to find them is seeing the sky shaking your head. The Magellanic Clouds are the closest galaxies to ours and visible to the naked eye. In Photo 1, the bright circular objects on the ground are Japanese antennas during measurement.

Photo 1: The Milky Way and Large and Small Magellanic Clouds over the ALMA Operations Support Facility (OSF).

“Night on the Milky Way Train�Eis a classic Japanese novel written by Kenji Miyazawa. In this novel, the Southern Cross is assumed to be the final destination and the entrance to the heaven. The Southern Cross is a crowd of beautiful stars, as expressed in his novel: “far downstream, emerging like a single tree out of the invisible water of the river, a cross studded with lights of blue, bitter-orange and every colour under the sun and crowned with a pale white halo of cloud (*translation by Roger Pulvers).�ERight beside the Southern Cross, there is a region called “Coalsack�Eto which Campanella pointed, saying “Hey, there’s the Coal Sack! �E.It’s a hole in the sky (*).�ELooking up at the Southern Cross, I always remember Giovanni’s saying “But what is real happiness? (*)�E Also, in the Cien Sonetos de Amor (100 Sonnets of Love) written by Pablo Neruda, a Nobel Prize Laureate in Literature and Chilean national hero, the Southern Cross is referred in the first phrase of the poem LXXXVI: “Oh Cruz del Sur, oh trebol de fosforo fragante (Oh Southern Cross, Oh clover of fragrant phosphorous). The Southern Cross (“Cruz del Sur�Ein Spanish) is a part of Crux and consists of four stars a, ß, ?, and d. Since any group of four stars can be a cross shape, it would be quite difficult to find the Southern Cross to unaccustomed eyes. Moreover, there is another group of four stars nearby called “False Cross,�Ewhich is sometimes confused with the Southern Cross. Photo 2 shows Japanese 12-m antennas during test observation at night. The Southern Cross is in the right side of the center of the main reflector of the most anterior antenna. The Southern Cross can be easily found by using two bright stars, a and ß Centauri below the ß of the Southern Cross (the lowest star). Tracing a line from the a and ß Centauri to the ß of the Southern Cross is a useful way to identify the Southern Cross.

Photo 2: Japanese 12-m antennas during test observation and the Southern Cross (just to the right of the main reflector of the most anterior antenna).

In Japan, we can see the central region of the Galaxy in the summer season (Photo 3). At the time of the Incan Civilization, people gave names of animals to dark clouds, such as llama (regarding α and β Centauri as eyes of the animal), fox, and snake, imagining these animals coming to the dark clouds to drink river water. The Coalsack was called “quail.” This fact shows that people at that time regarded a dark cloud in the Milky Way as something that has substance instead of a mere dark region without stars. The symbol of the Inca Empire, “Chakana” mark has a cross shape combined with a square, which is thought to represent the Southern Cross.

Photo 3: Dark clouds along the Milky Way (the Southern Cross and Coalsack are at the right edge of the Milky Way: photographed on July 23)