τ1 Hydrae (tau1 Hydrae)

Below the horizon. Rise: 11:03 | Tran: 16:53 | Set: 22:46

Alt: -36.74° Az: 62.12° Direction: South-West

τ1 Hydrae is a double main-sequence star of spectral class F6 in the constellation of Hydra.

τ1 Hydrae visual magnitude is 4.6. Because of its moderate brightness, τ1 Hydrae 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 τ1 Hydrae. The red arrow shows the motion of τ1 Hydrae during the next 1000 years (2.17 arcmin in Right Ascension and -0.25 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 09h 30m 26s

Declination -02° 52’ 52”

Hour Angle 15h 00m 41s

Sidereal Time 00h 31m 08s

J2000

Right Ascension 09h 29m 08s

Declination -02° 46’ 08”

Galactic Coordinates

Galactic Longitude 236.23°

Galactic Latitude 32.86°

Finder Chart

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Finder chart for τ1 Hydrae (tau1 Hydrae).

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 4.6

Class Main-sequence

Absolute magnitude 3.44

Spectral Type F6V

Color Index (B-V) 0.46

Temperature 6576K

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

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

Star System Properties

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

Main star magnitude 4.6

Secondary star magnitude 7.6

Magnitude difference 3

Separation 65.7 arcsec

Distance, Radial Speed, Proper Motion

τ1 Hydrae is distant 55.75 light years from the Sun and it is moving far from the Sun at the speed of 10 kilometers per second.

Distance (parsec) 17.10

Distance (light year) 55.75

Radial Speed 10 km/s

Proper Motion RA 0.13 arcsec/y

Proper Motion Dec -0.015"/y

Alternative Designations

Bayer designation τ1 Hydrae
(tau1 Hydrae)

Flamsteed designation 31 Hydrae

Henry Draper Catalogue HD81997

SAO Catalogue SAO136895

Hipparcos Catalogue HIP46509

Durchmusterung Catalogue BD-02 2901

Gliese Catalogue Gl 348 A

Visibility from Your Location

Today's τ1 Hydrae (tau1 Hydrae) rise, transit and set times from Tulsa, United States are the following (all times relative to the local timezone America/Chicago):

Azimuth: 92.9° RISE 11:03

Max altitude: 51.0° TRANSIT 16:53

Azimuth: 267.1° SET 22:46

Name:	Tulsa, United States
Latitude:	36° 9' 14.4" N
Longitude:	95° 59' 34.1" W
Timezone:	America/Chicago

Set Location

Other stars in Hydra