21 Aquilae

Above the horizon. Rise: 22:40 | Tran: 4:54 | Set: 11:04

Alt: 39.58° Az: 197.54° Direction: South-South-West

21 Aquilae is a variable and double bright giant star of spectral class B8 in the constellation of Aquila.

21 Aquilae visual magnitude is 5.15. Because of its faintness, 21 Aquilae is visible to the naked eye only from locations with very dark skies, while it is not visible at all from skies affected by light pollution.

DSS2 image of 21 Aquilae. The red arrow shows the motion of 21 Aquilae during the next 100000 years (15.00 arcmin in Right Ascension and -5.00 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 19h 14m 59s

Declination +02° 20’ 19”

Hour Angle 00h 53m 45s

Sidereal Time 20h 08m 44s

J2000

Right Ascension 19h 13m 42s

Declination +02° 17’ 36”

Galactic Coordinates

Galactic Longitude 37.52°

Galactic Latitude -3.9°

Finder Chart

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Finder chart for 21 Aquilae.

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 5.15

Class Bright giant

Absolute magnitude -1.32

Spectral Type B8II

Color Index (B-V) -0.07

Temperature 11092K

The red dot in the diagram below shows where 21 Aquilae is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 21 Aquilae. Attribution: Richard Powell / CC BY-SA

Star System Properties

21 Aquilae 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 21 Aquilae double sysyem:

Main star magnitude 5.15

Secondary star magnitude 12.65

Magnitude difference 7.5

Separation 36.2 arcsec

Distance, Radial Speed, Proper Motion

21 Aquilae is distant 640.47 light years from the Sun and it is moving towards the Sun at the speed of 5 kilometers per second.

Distance (parsec) 196.46

Distance (light year) 640.47

Radial Speed -5 km/s

Proper Motion RA 0.009 arcsec/y

Proper Motion Dec -0.003"/y

Alternative Designations

Flamsteed designation 21 Aquilae

Henry Draper Catalogue HD179761

SAO Catalogue SAO124408

Hipparcos Catalogue HIP94477

Durchmusterung Catalogue BD+02 3824

FK5 Catalogue 3537

General Catalogue of Variable Stars V1288 Aql

Aitken Double Star Catalogue ADS12182

Visibility from Your Location

Today's 21 Aquilae rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 87.7° RISE 22:40

Max altitude: 40.9° TRANSIT 4:54

Azimuth: 272.3° SET 11:04

Set Location

Other stars in Aquila