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A Complete Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
SunriseRise: 6:48  
clear_day Transit: 12:11  
SunsetSet: 17:34
wb_twilight Astronomical TwilightWhat's Visible Now?
All Constellations » Aries » 

τ1 Arietis (tau1 Arietis)

Altitude: -16.7°   Azimuth: 10.8°   Direction: North

τ1 Arietis is a multiple sub-giant star in the constellation of Aries.

τ1 Arietis visual magnitude is 5.28. Because of its reltive faintness, τ1 Arietis should be visible only from locations with dark skies, while it is not visible at all from skies affected by light pollution.

The proper motion of τ1 Arietis is 0.025 arcsec per year in Right Ascension and -0.024 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of τ1 Arietis (tau1 Arietis) star
DSS2 image of τ1 Arietis. The red arrow shows the motion of τ1 Arietis during the next 10000 years (4.17 arcmin in Right Ascension and -4.00 arcmin in declination);

Key facts about τ1 Arietis


τ1 Arietis (tau1 Arietis) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -16.7°
Azimuth: 10.8°
Direction: North

Celestial coordinates and finder chart of τ1 Arietis

τ1 Arietis 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 τ1 Arietis are provided in the following table:

03h 21m 13s
+21° 08’ 48”

The simplified sky map below shows the position of τ1 Arietis in the sky:

Finder chart τ1 Arietis (tau1 Arietis) star
Simplified finder chart for τ1 Arietis (tau1 Arietis).

Visibility of τ1 Arietis from your location

Location: Greenwich, United Kingdom edit_location_alt
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's τ1 Arietis (tau1 Arietis) rise, transit and set times from Greenwich, United Kingdom edit_location_alt are the following (all times relative to the local timezone Europe/London):

Azimuth: 68.9°
Max altitude: 59.7°
Azimuth: 291.1°

Distance of τ1 Arietis from the Sun and relative movement

τ1 Arietis is distant 461.76 light years from the Sun and it is moving far from the Sun at the speed of 14 kilometers per second.

141.64 pc
461.76 ly
14 km/s
0.025 arcsec/year
-0.024 arcsec/year

Spectral properties of τ1 Arietis

τ1 Arietis belongs to spectral class B5 and has a luminosity class of IV corresponding to a sub-giant star.


The red dot in the diagram below shows where τ1 Arietis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of τ1 Arietis. Attribution: Richard Powell / CC BY-SA

τ1 Arietis star system properties

τ1 Arietis 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 τ1 Arietis double sysyem:

0.2 arcsec

Alternative designations of τ1 Arietis

τ1 Arietis
(tau1 Arietis)