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A Complete Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:41  
clear_day Transit: 11:47  
SunsetSet: 15:53 south
sleep NighttimeWhat's Visible Now?
All Constellations » Ursa Major » 


Altitude: 22.8°   Azimuth: 356.1°   Direction: North

HR4840 is a variable hypergiant star in the constellation of Ursa Major.

HR4840 visual magnitude is 6.38. Because of its reltive faintness, HR4840 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 HR4840:


HR4840 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 22.8°
Azimuth: 356.1°
Direction: North

Celestial coordinates and finder chart of HR4840

HR4840 is situated close to the northern celestial pole and, as such, it is visible for most part of the year from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of HR4840 are provided in the following table:

12h 43m 04s
+61° 09’ 20”
Ursa Major

The simplified sky map below shows the position of HR4840 in the sky:

Finder chart HR4840 star
Simplified finder chart for HR4840.

Visibility of HR4840 from your location

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

HR4840 is circumpolar and transits at 08:03 UTC (altitude: 80.3°)

Digitized Sky Survey image of HR4840

The image below is a photograph of HR4840 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 HR4840 is -0.047 arcsec per year in Right Ascension and 0.026 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR4840 star
DSS2 image of HR4840. The red arrow shows the motion of HR4840 during the next 10000 years (-7.83 arcmin in Right Ascension and 4.33 arcmin in declination);

Distance of HR4840 from the Sun and relative movement

HR4840 is distant 477.31 light years from the Sun and it is moving towards the Sun at the speed of 6 kilometers per second.

146.41 pc
477.31 ly
-6 km/s
-0.047 arcsec/year
0.026 arcsec/year

Spectral properties of HR4840

HR4840 belongs to spectral class K0


The red dot in the diagram below shows where HR4840 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR4840. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR4840