τ1 Aquarii (tau1 Aquarii)

Altitude: -38.8° Azimuth: 300.7° Direction: West-North-West

τ1 Aquarii is a multiple hypergiant star in the constellation of Aquarius.

τ1 Aquarii visual magnitude is 5.66. Because of its reltive faintness, τ1 Aquarii 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 Aquarii:

Color of τ1 Aquarii ⬤

Magnitude of τ1 Aquarii 5.66

Class Hypergiant

VISIBILITY RIGHT NOW

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

Altitude: -38.8°
Azimuth: 300.7°
Direction: West-North-West

Celestial coordinates and finder chart of τ1 Aquarii

τ1 Aquarii 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 Aquarii are provided in the following table:

Right Ascension J2000 22h 47m 42s

Declination J2000 -14° 03’ 23”

Galactic Longitude 51.06°

Galactic Latitude -58.35°

Constellation Aquarius

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

Finder chart τ1 Aquarii (tau1 Aquarii) star

Simplified finder chart for τ1 Aquarii (tau1 Aquarii).

Visibility of τ1 Aquarii 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 Aquarii (tau1 Aquarii) 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: 104.1° RISE 1:49

Max altitude: 24.5° TRANSIT 6:34

Azimuth: 255.9° SET 11:19

RIGHT NOW τ1 Aquarii (tau1 Aquarii) is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of τ1 Aquarii

The image below is a photograph of τ1 Aquarii 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 Aquarii is 0.032 arcsec per year in Right Ascension and -0.009 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of τ1 Aquarii. The red arrow shows the motion of τ1 Aquarii during the next 10000 years (5.33 arcmin in Right Ascension and -1.50 arcmin in declination);

Distance of τ1 Aquarii from the Sun and relative movement

τ1 Aquarii is distant 259.76 light years from the Sun and it is moving far from the Sun at the speed of 15 kilometers per second.

Distance (parsec) 79.68 pc

Distance (light year) 259.76 ly

Heliocentric radial velocity 15 km/s

Proper Motion RA 0.032 arcsec/year

Proper Motion Dec -0.009 arcsec/year

Spectral properties of τ1 Aquarii

τ1 Aquarii belongs to spectral class A0 and has a luminosity class of V corresponding to a hypergiant star.

Absolute magnitude 1.15

Spectral Type A0V

Color Index (B-V) -0.05

Temperature of τ1 Aquarii 10795K

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

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

τ1 Aquarii star system properties

τ1 Aquarii is a visual double star which can be observed with binoculars or small telescopes. The table below shows key information about the τ1 Aquarii double sysyem:

Main star magnitude 5.66

Secondary star magnitude 9.56

Magnitude difference 3.9

Separation 23.7 arcsec

Alternative designations of τ1 Aquarii

Bayer designation τ1 Aquarii
(tau1 Aquarii)

Flamsteed designation 69 Aquarii

Henry Draper Catalogue HD215766

SAO Catalogue SAO165298

Hipparcos Catalogue HIP112542

Durchmusterung Catalogue BD-14 6346

Aitken Double Star Catalogue ADS16268

In Evidence

Other stars in Aquarius