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Aldebaran - α Tauri (alpha Tauri)

Aldebaran, also designated as α Tauri (alpha Tauri), is a variable and multiple giant star in the constellation of Taurus.

Aldebaran visual magnitude is 0.85, making it the 13th brightest star in the sky. Thanks to its high brightness, Aldebaran 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 Aldebaran:

Color of Aldebaran ⬤

Magnitude of Aldebaran 0.85

Class Giant

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

Celestial coordinates and finder chart of Aldebaran

Aldebaran 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 Aldebaran are provided in the following table:

Right Ascension J2000 04h 35m 55s

Declination J2000 +16° 30’ 33”

Galactic Longitude 180.97°

Galactic Latitude -20.25°

Constellation Taurus

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

Finder chart Aldebaran - α Tauri (alpha Tauri) star

Simplified finder chart for Aldebaran - α Tauri (alpha Tauri).

Visibility of Aldebaran from your location

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

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

Azimuth: 73.5° RISE 9:43

Max altitude: 55.0° TRANSIT 17:08

Azimuth: 286.5° SET 0:33

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

Digitized Sky Survey image of Aldebaran

The image below is a photograph of Aldebaran 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 Aldebaran is 0.063 arcsec per year in Right Ascension and -0.19 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of Aldebaran - α Tauri (alpha Tauri) star

DSS2 image of Aldebaran. The red arrow shows the motion of Aldebaran during the next 1000 years (1.05 arcmin in Right Ascension and -3.17 arcmin in declination);

Distance of Aldebaran from the Sun and relative movement

Aldebaran is distant 65.08 light years from the Sun and it is moving far from the Sun at the speed of 54 kilometers per second.

Distance (parsec) 19.96 pc

Distance (light year) 65.08 ly

Heliocentric radial velocity 54 km/s

Proper Motion RA 0.063 arcsec/year

Proper Motion Dec -0.19 arcsec/year

Spectral properties of Aldebaran

Aldebaran belongs to spectral class K5 and has a luminosity class of III corresponding to a giant star.

Absolute magnitude -0.65

Spectral Type K5III

Color Index (B-V) 1.54

Temperature of Aldebaran 3734K

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

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

Aldebaran star system properties

Aldebaran 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 Aldebaran double sysyem:

Main star magnitude 0.85

Secondary star magnitude 10.65

Magnitude difference 9.8

Separation 121.7 arcsec

Alternative designations of Aldebaran

Proper Name Aldebaran

Bayer designation α Tauri
(alpha Tauri)

Flamsteed designation 87 Tauri

Henry Draper Catalogue HD29139

SAO Catalogue SAO94027

Hipparcos Catalogue HIP21421

Durchmusterung Catalogue BD+16 629

Gliese Catalogue Gl 171.1A

FK5 Catalogue 168

General Catalogue of Variable Stars Alp Tau

Aitken Double Star Catalogue ADS3321

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