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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: 7:48  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
sleep NighttimeWhat's Visible Now?
All Constellations » Hydra » 


Altitude: -52.2°   Azimuth: 61.7°   Direction: East-North-East

HR4579 is a double hypergiant star in the constellation of Hydra.

HR4579 visual magnitude is 6.43. Because of its reltive faintness, HR4579 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 HR4579:


HR4579 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -52.2°
Azimuth: 61.7°
Direction: East-North-East

Celestial coordinates and finder chart of HR4579

HR4579 is situated south of the celestial equator, as such, it is more easily visible from the southern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of HR4579 are provided in the following table:

11h 58m 54s
-25° 54’ 32”

The simplified sky map below shows the position of HR4579 in the sky:

Finder chart HR4579 star
Simplified finder chart for HR4579.

Visibility of HR4579 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 HR4579 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: 115.9°
Max altitude: 12.6°
Azimuth: 244.1°

Digitized Sky Survey image of HR4579

The image below is a photograph of HR4579 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 HR4579 is -0.027 arcsec per year in Right Ascension and -0.019 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR4579 star
DSS2 image of HR4579. The red arrow shows the motion of HR4579 during the next 10000 years (-4.50 arcmin in Right Ascension and -3.17 arcmin in declination);

Distance of HR4579 from the Sun and relative movement

HR4579 is distant 890.71 light years from the Sun and it is moving far from the Sun at the speed of 13 kilometers per second.

273.22 pc
890.71 ly
13 km/s
-0.027 arcsec/year
-0.019 arcsec/year

Spectral properties of HR4579

HR4579 belongs to spectral class A0 and has a luminosity class of V corresponding to a hypergiant star.


The red dot in the diagram below shows where HR4579 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR4579. Attribution: Richard Powell / CC BY-SA

HR4579 star system properties

HR4579 is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the HR4579 double sysyem:

0.2 arcsec

Alternative designations of HR4579