Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:52  
clear_day Transit: 12:49  
SunsetSet: 18:46 south
sunny DaytimeWhat's Visible Now
All Constellations » Serpens » 

40 Serpentis

Altitude: 47.1°   Azimuth: 181.3°   Direction: South

40 Serpentis is a variable main-sequence star in the constellation of Serpens.

40 Serpentis visual magnitude is 6.29. Because of its reltive faintness, 40 Serpentis should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about 40 Serpentis:


40 Serpentis is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 47.1°
Azimuth: 181.3°
Direction: South

Celestial coordinates and finder chart of 40 Serpentis

40 Serpentis 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 40 Serpentis are provided in the following table:

15h 54m 40s
+08° 34’ 49”

The simplified sky map below shows the position of 40 Serpentis in the sky:

Finder chart 40 Serpentis star
Simplified finder chart for 40 Serpentis.

Visibility of 40 Serpentis from your location

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

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

Azimuth: 81.4°
Max altitude: 47.1°
Azimuth: 278.6°

Digitized Sky Survey image of 40 Serpentis

The image below is a photograph of 40 Serpentis 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 40 Serpentis is 0.002 arcsec per year in Right Ascension and 0.002 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of 40 Serpentis star
DSS2 image of 40 Serpentis. The red arrow shows the motion of 40 Serpentis during the next 100000 years (3.33 arcmin in Right Ascension and 3.33 arcmin in declination);

Distance of 40 Serpentis from the Sun and relative movement

40 Serpentis is distant 240.77 light years from the Sun and it is moving towards the Sun at the speed of 25 kilometers per second.

73.86 pc
240.77 ly
-25 km/s
0.002 arcsec/year
0.002 arcsec/year

Spectral properties of 40 Serpentis

40 Serpentis belongs to spectral class A7 and has a luminosity class of V corresponding to a main-sequence star.


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

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

Alternative designations of 40 Serpentis

40 Serpentis