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public LocationGreenwich, United Kingdom
TimezoneEurope/London
Sunrise: 4:42 
Transit: 12:59 
Sunset: 21:16
sunny   (Daytime)   What's Visible Now?

τ Orionis (tau Orionis)

Above the horizon.  Rise: 7:17 | Tran: 12:40 | Set: 18:04
Altitude: 3.6°   Azimuth: 254.2°   Direction: West-South-West

τ Orionis is a multiple giant star of spectral class B5 in the constellation of Orion.

τ Orionis visual magnitude is 3.6. Because of its moderate brightness, τ Orionis 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.

Celestial coordinates and finder chart of τ Orionis

Finder chart τ Orionis (tau Orionis) star
Simplified finder chart for τ Orionis (tau Orionis).

τ Orionis is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of τ Orionis are provided in the following table:

05h 17m 36s
-06° 50’ 39”
208.28°
-23.96°
Orion
Image of τ Orionis (tau Orionis) star
DSS2 image of τ Orionis. The red arrow shows the motion of τ Orionis during the next 10000 years (-2.50 arcmin in Right Ascension and -1.33 arcmin in declination);

Key facts about τ Orionis

3.6
Giant

and has a luminosity class of III corresponding to a giant star.

-2.55
B5III
11744K

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

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

τ Orionis star system properties

τ Orionis is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the τ Orionis double sysyem:

3.6
10.8
7.2
36 arcsec

Distance of τ Orionis from the Sun and relative movement

τ Orionis is distant 554.42 light years from the Sun and it is moving far from the Sun at the speed of 20 kilometers per second.

170.07 pc
554.42 ly
20 km/s
-0.015 arcsec/year
-0.008 arcsec/year

Alternative designations of τ Orionis

τ Orionis
(tau Orionis)
SAO131952
SAO131952

Visibility of τ Orionis from your location

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

Azimuth: 96.8°
Max altitude: 31.7°
Azimuth: 263.2°