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Alphard - α Hydrae (alpha Hydrae)

Alphard, also designated as α Hydrae (alpha Hydrae), is a variable and multiple bright giant star in the constellation of Hydra.

Alphard visual magnitude is 1.98, making it the 45th brightest star in the sky. Thanks to its high brightness, Alphard 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 Alphard:

Color of Alphard ⬤

Magnitude of Alphard 1.98

Class Bright giant

VISIBILITY RIGHT NOW Alphard - α Hydrae (alpha Hydrae) is below the horizon from Greenwich, United Kingdom [change].

Celestial coordinates and finder chart of Alphard

Alphard 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 Alphard are provided in the following table:

Right Ascension J2000 09h 27m 35s

Declination J2000 -08° 39’ 30”

Galactic Longitude 241.49°

Galactic Latitude 29.05°

Constellation Hydra

The simplified sky map below shows the position of Alphard in the sky:

Finder chart Alphard - α Hydrae (alpha Hydrae) star

Simplified finder chart for Alphard - α Hydrae (alpha Hydrae).

Visibility of Alphard from your location

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

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

Azimuth: 98.7° RISE 16:08

Max altitude: 29.9° TRANSIT 21:23

Azimuth: 261.3° SET 2:41

RIGHT NOW Alphard - α Hydrae (alpha Hydrae) is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of Alphard

The image below is a photograph of Alphard 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 Alphard is -0.014 arcsec per year in Right Ascension and 0.033 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of Alphard - α Hydrae (alpha Hydrae) star

DSS2 image of Alphard. The red arrow shows the motion of Alphard during the next 10000 years (-2.33 arcmin in Right Ascension and 5.50 arcmin in declination);

Distance of Alphard from the Sun and relative movement

Alphard is distant 177.17 light years from the Sun and it is moving towards the Sun at the speed of 4 kilometers per second.

Distance (parsec) 54.35 pc

Distance (light year) 177.17 ly

Heliocentric radial velocity -4 km/s

Proper Motion RA -0.014 arcsec/year

Proper Motion Dec 0.033 arcsec/year

Spectral properties of Alphard

Alphard belongs to spectral class K3 and has a luminosity class of II corresponding to a bright giant star.

Absolute magnitude -1.70

Spectral Type K3II

Color Index (B-V) 1.44

Temperature of Alphard 3886K

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

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

Alphard star system properties

Alphard 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 Alphard double sysyem:

Main star magnitude 1.98

Secondary star magnitude 9.48

Magnitude difference 7.5

Separation 283.1 arcsec

Alternative designations of Alphard

Proper Name Alphard

Bayer designation α Hydrae
(alpha Hydrae)

Flamsteed designation 30 Hydrae

Henry Draper Catalogue HD81797

SAO Catalogue SAO136871

Hipparcos Catalogue HIP46390

Durchmusterung Catalogue BD-08 2680

FK5 Catalogue 354

General Catalogue of Variable Stars 4496

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