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: 6:46  
clear_day Transit: 12:51  
SunsetSet: 18:55 south
wb_twilight Nautical TwilightWhat's Visible Now
All Constellations » Ursa Major » 


Altitude: 48.0°   Azimuth: 51.7°   Direction: North-East

HR3870 is a variable giant star in the constellation of Ursa Major.

HR3870 visual magnitude is 5.2. Because of its reltive faintness, HR3870 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 HR3870:


HR3870 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 48.0°
Azimuth: 51.7°
Direction: North-East

Celestial coordinates and finder chart of HR3870

HR3870 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 HR3870 are provided in the following table:

09h 46m 31s
+57° 07’ 41”
Ursa Major

The simplified sky map below shows the position of HR3870 in the sky:

Finder chart HR3870 star
Simplified finder chart for HR3870.

Visibility of HR3870 from your location

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

HR3870 is circumpolar and transits at 09:38 UTC (altitude: 84.4°)

Digitized Sky Survey image of HR3870

The image below is a photograph of HR3870 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 HR3870 is 0.004 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 HR3870 star
DSS2 image of HR3870. The red arrow shows the motion of HR3870 during the next 10000 years (0.67 arcmin in Right Ascension and 5.67 arcmin in declination);

Distance of HR3870 from the Sun and relative movement

HR3870 is distant 556.31 light years from the Sun and it is moving far from the Sun at the speed of 8 kilometers per second.

170.65 pc
556.31 ly
8 km/s
0.004 arcsec/year
0.034 arcsec/year

Spectral properties of HR3870

HR3870 belongs to spectral class M3 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where HR3870 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR3870. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR3870