Hydra in colors

Here, at a glance, are the colors of all the stars up to the sixth magnitude in the constellation Hydra, the longest constellation in the night sky.

In one of the myths in which it features, it is identified with the nine-headed Hydra defeated by Heracles in the second of his Twelve Labours. And indeed, in the night sky, its Head lies at the feet of Cancer and Leo, constellations with which it shares the same myth.

Only one of the heads is visible in the sky, and when it appears in the early evening in the east, it heralds the arrival of spring: to see its tail set, however, one must wait until the end of the night.

From an overview of its colours, it is clear that the constellation is largely made up of yellow and orange stars; that the blue and pale yellow ones are concentrated mainly on the Head, and that along the body there are also numerous red ones, such as U and V Hya, two famous carbonstars, respectively one of the brightest and one of the reddest in the night sky.

Hydra, along with Pisces and Cetus, can therefore be counted among the most yellow/orange constellations in the night sky.

Collage of 119 shots deliberately taken out of focus using an 18" Sky-Watcher Dobsonian telescope and an A5 smartphone at ISO 800.

Dobson Stargate Sky-Watcher 18" and Smartphone A5

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