40 Persei

Above the horizon. Rise: 3:01 | Tran: 12:50 | Set: 22:39

Alt: 37.79° Az: 80.60° Direction: East

40 Persei is a double hypergiant star of spectral class B0 in the constellation of Perseus.

40 Persei visual magnitude is 4.97. Because of its moderate brightness, 40 Persei is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

DSS2 image of 40 Persei. The red arrow shows the motion of 40 Persei during the next 100000 years (-8.33 arcmin in Right Ascension and -15.00 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 03h 43m 59s

Declination +34° 02’ 39”

Hour Angle 19h 19m 10s

Sidereal Time 23h 03m 09s

J2000

Right Ascension 03h 42m 22s

Declination +33° 57’ 54”

Galactic Coordinates

Galactic Longitude 158.92°

Galactic Latitude -16.7°

Finder Chart

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Finder chart for 40 Persei.

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 4.97

Class Hypergiant

Absolute magnitude -2.29

Spectral Type B0V

Color Index (B-V) -0.01

Temperature 10252K

The red dot in the diagram below shows where 40 Persei is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 40 Persei. Attribution: Richard Powell / CC BY-SA

Star System Properties

40 Persei is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the 40 Persei double sysyem:

Main star magnitude 4.97

Secondary star magnitude 9.97

Magnitude difference 5

Separation 20 arcsec

Distance, Radial Speed, Proper Motion

40 Persei is distant 923.51 light years from the Sun and it is moving far from the Sun at the speed of 20 kilometers per second.

Distance (parsec) 283.29

Distance (light year) 923.51

Radial Speed 20 km/s

Proper Motion RA -0.005 arcsec/y

Proper Motion Dec -0.009"/y

Alternative Designations

Flamsteed designation 40 Persei

Henry Draper Catalogue HD22951

SAO Catalogue SAO56646

Hipparcos Catalogue HIP17313

Durchmusterung Catalogue BD+33 698

Aitken Double Star Catalogue ADS2699

Visibility from Your Location

Today's 40 Persei rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 56.0° RISE 3:01

Max altitude: 72.6° TRANSIT 12:50

Azimuth: 304.0° SET 22:39

Set Location

Other stars in Perseus