English: The Lesser Water Snake
Size Ranking: 61st
Area: 243 square degrees
Fully Visible: 8°N-90°S
The constellation chosen this month, Hydrus, is, yet again, another of the numerous lesser southern star patterns.
Hydrus is a fainter constellation invented in the 16th century by the Dutch navigators, Pieter Dirkszoon Keyser and Frederick deHoutman, and is situated between Achernar, αEri, and the south celestial pole. A further guide is to locate the two Magellanic clouds and Hydrus resides in the intervening area.
This constellation depicts a small water snake and should not be confused with the large water snake, Hydra, known since the time of the ancient Greeks.
Features of Interest:
One reference consulted described this constellation thus- ’A constellation in the far south – remarkably lacking in interesting objects.’! However, this is nearly correct, but not quite.
αHyi, is magnitude 2.9 white main-sequence star and is 71ly distant.
βHyi, at magnitude 2.8, is the constellation’s brightest star. It is a yellow star and is 24ly away.
γHyi, is a red giant star of magnitude 3.2 and 214ly out in space.
π¹,π²Hyi, is a binocular pair of unrelated red and orange giants. π¹ lies 740ly away and is of magnitude 5.6, while π² is magnitude 5.7 and lies 468ly distant.
1. Redshift 2 – Maris Multimedia
2. The Guinness Book of Astronomy – Patrick Moore
3. Stars and Planets – Ian Ridpath and Wil Tirion
4. Sky Charts – Cartes du Ciel V 2.75.
5. NASA Picture of the day: