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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: 7:50  
clear_day Transit: 11:50  
SunsetSet: 15:49 south
sunny DaytimeWhat's Visible Now?
All Constellations » Cepheus » 


Altitude: 38.4°   Azimuth: 34.8°   Direction: North-East

HR8399 is a variable and double hypergiant star in the constellation of Cepheus.

HR8399 visual magnitude is 6.66. Because of its reltive faintness, HR8399 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 HR8399:


HR8399 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 38.4°
Azimuth: 34.8°
Direction: North-East

Celestial coordinates and finder chart of HR8399

HR8399 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 HR8399 are provided in the following table:

22h 00m 39s
+62° 29’ 17”

The simplified sky map below shows the position of HR8399 in the sky:

Finder chart HR8399 star
Simplified finder chart for HR8399.

Visibility of HR8399 from your location

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

HR8399 is circumpolar and transits at 16:51 UTC (altitude: 79.0°)

Digitized Sky Survey image of HR8399

The image below is a photograph of HR8399 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 HR8399 is -0.001 arcsec per year in Right Ascension and 0.007 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of HR8399 star
DSS2 image of HR8399. The red arrow shows the motion of HR8399 during the next 100000 years (-1.67 arcmin in Right Ascension and 11.67 arcmin in declination);

Distance of HR8399 from the Sun and relative movement

HR8399 is distant 23,285.71 light years from the Sun and it is moving towards the Sun at the speed of 20 kilometers per second.

7,142.86 pc
23,285.71 ly
-20 km/s
-0.001 arcsec/year
0.007 arcsec/year

Spectral properties of HR8399

HR8399 belongs to spectral class B0 and has a luminosity class of IV corresponding to a hypergiant star.


The red dot in the diagram below shows where HR8399 is situated in the HertzsprungÔÇôRussell diagram.

HR Diagram
H-R diagram showing the position of HR8399. Attribution: Richard Powell / CC BY-SA

HR8399 star system properties

HR8399 is a visual double star which can be observed with the help of large telescopes. The table below shows key information about the HR8399 double sysyem:

0.9 arcsec

Alternative designations of HR8399