τ Librae (tau Librae)

Below the horizon. Rise: 22:02 | Tran: 1:00 | Set: 3:54

Alt: -37.49° Az: 267.48° Direction: West

τ Librae is a main-sequence star of spectral class B2 in the constellation of Libra.

τ Librae visual magnitude is 3.66. Because of its moderate brightness, τ Librae is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

DSS2 image of τ Librae. The red arrow shows the motion of τ Librae during the next 10000 years (-2.50 arcmin in Right Ascension and -5.00 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 15h 40m 13s

Declination -29° 51’ 32”

Hour Angle 07h 35m 41s

Sidereal Time 23h 15m 55s

J2000

Right Ascension 15h 38m 39s

Declination -29° 46’ 40”

Galactic Coordinates

Galactic Longitude 341.06°

Galactic Latitude 20.45°

Finder Chart

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Finder chart for τ Librae (tau Librae).

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 3.66

Class Main-sequence

Absolute magnitude -2.01

Spectral Type B2V

Color Index (B-V) -0.17

Temperature 12902K

The red dot in the diagram below shows where τ Librae is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of τ Librae. Attribution: Richard Powell / CC BY-SA

Distance, Radial Speed, Proper Motion

τ Librae is distant 444.75 light years from the Sun and it is moving far from the Sun at the speed of 3 kilometers per second.

Distance (parsec) 136.43

Distance (light year) 444.75

Radial Speed 3 km/s

Proper Motion RA -0.015 arcsec/y

Proper Motion Dec -0.03"/y

Alternative Designations

Bayer designation τ Librae
(tau Librae)

Flamsteed designation 40 Librae

Henry Draper Catalogue HD139365

SAO Catalogue SAO183649

Hipparcos Catalogue HIP76600

Durchmusterung Catalogue CD-2911837

Visibility from Your Location

Today's τ Librae (tau Librae) rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 119.9° RISE 22:02

Max altitude: 8.7° TRANSIT 1:00

Azimuth: 240.1° SET 3:54

Set Location

Other stars in Libra