Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:47  
clear_day Transit: 12:56  
SunsetSet: 21:06 south
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All Constellations » Grus » 

τ1 Gruis (tau1 Gruis)

τ1 Gruis is a hypergiant star in the constellation of Grus.

τ1 Gruis visual magnitude is 6.04. Because of its reltive faintness, τ1 Gruis should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about τ1 Gruis:

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

Celestial coordinates and finder chart of τ1 Gruis

τ1 Gruis is situated south of the celestial equator, as such, it is more easily visible from the southern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of τ1 Gruis are provided in the following table:

22h 53m 37s
-48° 35’ 53”

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

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

Visibility of τ1 Gruis from your location

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

τ1 Gruis (tau1 Gruis) is currently not visible from Greenwich, United Kingdom edit_location_alt

Digitized Sky Survey image of τ1 Gruis

The image below is a photograph of τ1 Gruis from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of τ1 Gruis is 0.216 arcsec per year in Right Ascension and -0.078 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of τ1 Gruis (tau1 Gruis) star
DSS2 image of τ1 Gruis. The red arrow shows the motion of τ1 Gruis during the next 1000 years (3.60 arcmin in Right Ascension and -1.30 arcmin in declination);

Distance of τ1 Gruis from the Sun and relative movement

τ1 Gruis is distant 108.52 light years from the Sun and it is moving towards the Sun at the speed of 1 kilometers per second.

33.29 pc
108.52 ly
-1 km/s
0.216 arcsec/year
-0.078 arcsec/year

Spectral properties of τ1 Gruis

τ1 Gruis belongs to spectral class G0 and has a luminosity class of V corresponding to a hypergiant star.


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

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

Alternative designations of τ1 Gruis

τ1 Gruis
(tau1 Gruis)