Transit Date of principal star:
24 November

Horologium, "The Pendulum Clock", is one of those obscure constellations of the southern hemisphere invented by Nicolas Louis de Lacaille in the mid-eighteenth century.

Like the majority of Lacaille's constellations, Horologium is a curious asterism, and has very little to offer. There are no binaries of any interest here, and no deep sky objects. One Mira-type variable (R Hor) is a rather interesting star.

Its Bayer stars are few and rather faint, ranging from 3.9 to 5.4.

Variable stars:

R Horologium is a Mira-type variable with a very wide range. Indeed, this star has one of the largest ranges known: from a fairly bright 4.7 to an extremely faint 14.3 visual magnitude. The period is 407.6 days. In the year 2000 the maximum should be achieved near the end of September.

The star is two degrees NE of iota Horologii.

For a more detailed appreciation of Horologium, visit the Binocular Section.

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© Richard Dibon-Smith.