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: 6:55  
clear_day Transit: 12:49  
SunsetSet: 18:41 south
sunny DaytimeWhat's Visible Now
All Constellations » Cancer » 


Altitude: 26.5°   Azimuth: 287.3°   Direction: West-North-West

HR3639 is a variable giant star in the constellation of Cancer.

HR3639 visual magnitude is 5.95. Because of its reltive faintness, HR3639 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 HR3639:


HR3639 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 26.5°
Azimuth: 287.3°
Direction: West-North-West

Celestial coordinates and finder chart of HR3639

HR3639 is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of HR3639 are provided in the following table:

09h 10m 38s
+30° 57’ 47”

The simplified sky map below shows the position of HR3639 in the sky:

Finder chart HR3639 star
Simplified finder chart for HR3639.

Visibility of HR3639 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 HR3639 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: 59.0°
Max altitude: 69.5°
Azimuth: 301.0°

Digitized Sky Survey image of HR3639

The image below is a photograph of HR3639 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 HR3639 is -0.021 arcsec per year in Right Ascension and -0.034 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR3639 star
DSS2 image of HR3639. The red arrow shows the motion of HR3639 during the next 10000 years (-3.50 arcmin in Right Ascension and -5.67 arcmin in declination);

Distance of HR3639 from the Sun and relative movement

HR3639 is distant 397.08 light years from the Sun and it is moving far from the Sun at the speed of 14 kilometers per second.

121.80 pc
397.08 ly
14 km/s
-0.021 arcsec/year
-0.034 arcsec/year

Spectral properties of HR3639

HR3639 belongs to spectral class M6 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where HR3639 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR3639. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR3639