γ Hydrae (gamma Hydrae)

γ Hydrae is a variable and double giant star in the constellation of Hydra.

γ Hydrae visual magnitude is 3. Thanks to its high brightness, γ Hydrae is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.

The table below summarizes the key facts about γ Hydrae:

Color of γ Hydrae ⬤

Magnitude of γ Hydrae 3

Class Giant

VISIBILITY RIGHT NOW γ Hydrae (gamma Hydrae) is below the horizon from Greenwich, United Kingdom [change].

Celestial coordinates and finder chart of γ Hydrae

γ Hydrae 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 γ Hydrae are provided in the following table:

Right Ascension J2000 13h 18m 55s

Declination J2000 -23° 10’ 18”

Galactic Longitude 311.1°

Galactic Latitude 39.26°

Constellation Hydra

The simplified sky map below shows the position of γ Hydrae in the sky:

Finder chart γ Hydrae (gamma Hydrae) star

Simplified finder chart for γ Hydrae (gamma Hydrae).

Visibility of γ Hydrae from your location

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

Today's γ Hydrae (gamma Hydrae) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 113.2° RISE 21:45

Max altitude: 15.3° TRANSIT 1:38

Azimuth: 246.8° SET 5:27

RIGHT NOW γ Hydrae (gamma Hydrae) is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of γ Hydrae

The image below is a photograph of γ Hydrae 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 γ Hydrae is 0.064 arcsec per year in Right Ascension and -0.045 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of γ Hydrae. The red arrow shows the motion of γ Hydrae during the next 10000 years (10.67 arcmin in Right Ascension and -7.50 arcmin in declination);

Distance of γ Hydrae from the Sun and relative movement

γ Hydrae is distant 132.04 light years from the Sun and it is moving towards the Sun at the speed of 5 kilometers per second.

Distance (parsec) 40.50 pc

Distance (light year) 132.04 ly

Heliocentric radial velocity -5 km/s

Proper Motion RA 0.064 arcsec/year

Proper Motion Dec -0.045 arcsec/year

Spectral properties of γ Hydrae

γ Hydrae belongs to spectral class G8 and has a luminosity class of III corresponding to a giant star.

Absolute magnitude -0.04

Spectral Type G8III

Color Index (B-V) 0.92

Temperature of γ Hydrae 4943K

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

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

γ Hydrae star system properties

γ Hydrae 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 γ Hydrae double sysyem:

Main star magnitude 3

Secondary star magnitude 9.7

Magnitude difference 6.7

Separation 138.4 arcsec

Alternative designations of γ Hydrae

Bayer designation γ Hydrae
(gamma Hydrae)

Flamsteed designation 46 Hydrae

Henry Draper Catalogue HD115659

SAO Catalogue SAO181543

Hipparcos Catalogue HIP64962

Durchmusterung Catalogue BD-22 3554

FK5 Catalogue 495

General Catalogue of Variable Stars 6180

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