Iota1 Librae

Iota¹ Librae is a quadruple star system in the constellation Libra. Its name is a Bayer designation that is Latinized from, and abbreviated or. Its apparent magnitude is 4.54. It is located 379 light years from earth.

Visibility

Due to its southern location, although the star can be seen from most regions of the earth, observers in the southern hemisphere are more advantaged. Near Antarctica, it appears circumpolar, while it always remains invisible only in the vicinity of the Arctic Circle. Its magnitude of 4.5 means that naked eye visibility is dependent on a sky sufficiently free from the effects of light pollution.
The best time for observation in the evening sky falls in the months between May and September; from both hemispheres of the period of visibility remains approximately the same, thanks to the position of the star not far from the celestial equator.

Physical

Iota¹ Librae is a quadruple star system. The inner pair, designated components Aa and Ab, form a spectroscopic binary with an orbital period of 22.35 years and an eccentricity of 0.35. The brighter member has a stellar classification of, indicating it is a B-type subgiant star with an overabundance of silicon in the photosphere. It is a variable star of the Alpha2 Canum Venaticorum type with a magnitude that varies from 4.53 to 4.56, while its spectrum likewise shows variability. The secondary component is of class B9. The two stars are very close together, respectively of magnitude 5.10 and 5.60.
The two other stars are the components C and D; separated by 57.8" from AB and 2.058" from each other. The combined spectrum is G5IV, and each star has masses of 0.98 and 0.91 solar masses, and magnitudes 10.40 and 10.90, respectively.
Due to its position on the ecliptic, it is sometimes obscured by the Moon or planets. A lunar occultation took place April 4, 2012.