20 Persei

Above the horizon. Rise: 16:50 | Tran: 4:32 | Set: 16:11

Alt: 4.81° Az: 26.37° Direction: North-North-East

20 Persei is a variable and multiple sub-giant star of spectral class F4 in the constellation of Perseus.

20 Persei visual magnitude is 5.33. Because of its faintness, 20 Persei 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 20 Persei. The red arrow shows the motion of 20 Persei during the next 10000 years (7.83 arcmin in Right Ascension and -12.83 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 02h 55m 16s

Declination +38° 26’ 13”

Hour Angle 14h 17m 36s

Sideral Time 17h 12m 53s

J2000

Right Ascension 02h 53m 42s

Declination +38° 20’ 14”

Galactic Coordinates

Galactic Longitude 147.81°

Galactic Latitude -18.55°

Finder Chart

Simplified finder chart for 20 Persei.

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 5.33

Class Sub-giant

Absolute magnitude 1.04

Spectral Type F4IV

Color Index (B-V) 0.41

Temperature 6827K

The red dot in the diagram below shows where 20 Persei is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 20 Persei. Attribution: Richard Powell / CC BY-SA

Star System Properties

20 Persei 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 20 Persei double sysyem:

Main star magnitude 5.33

Secondary star magnitude 5.93

Magnitude difference 0.6

Separation 0.2 arcsec

Distance, Radial Speed, Proper Motion

20 Persei is distant 235.04 light years from the Sun and it is moving far from the Sun at the speed of 6 kilometers per second.

Distance (parsec) 72.10

Distance (light year) 235.04

Radial Speed 6 km/s

Proper Motion RA 0.047 arcsec/y

Proper Motion Dec -0.077"/y

Alternative Designations

Flamsteed designation 20 Persei

Henry Draper Catalogue HD17904

SAO Catalogue SAO55975

Hipparcos Catalogue HIP13490

Durchmusterung Catalogue BD+37 655

General Catalogue of Variable Stars 977

Aitken Double Star Catalogue ADS2200

Visibility from Your Location

Today's 20 Persei rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 51.6° RISE 16:50

Max altitude: 77.0° TRANSIT 4:32

Azimuth: 308.4° SET 16:11

Name:	Greenwich, UK
Latitude:	51° 28' 48.0" N
Longitude:	0° 0' 0.0" E
Timezone:	Europe/London

Location

Other stars in Perseus