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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: 7:38  
clear_day Transit: 11:46  
SunsetSet: 15:54 south
sleep NighttimeWhat's Visible Now?
All Constellations » Sagittarius » 


Altitude: -69.0°   Azimuth: 52.2°   Direction: North-East

HR7728 is a variable and multiple giant star in the constellation of Sagittarius.

HR7728 visual magnitude is 6.39. Because of its reltive faintness, HR7728 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 HR7728:


HR7728 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -69.0°
Azimuth: 52.2°
Direction: North-East

Celestial coordinates and finder chart of HR7728

HR7728 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 HR7728 are provided in the following table:

20h 16m 23s
-36° 27’ 15”

The simplified sky map below shows the position of HR7728 in the sky:

Finder chart HR7728 star
Simplified finder chart for HR7728.

Visibility of HR7728 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 HR7728 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: 126.5°
Max altitude: 2.1°
Azimuth: 233.5°

Digitized Sky Survey image of HR7728

The image below is a photograph of HR7728 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 HR7728 is 0.009 arcsec per year in Right Ascension and -0.042 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR7728 star
DSS2 image of HR7728. The red arrow shows the motion of HR7728 during the next 10000 years (1.50 arcmin in Right Ascension and -7.00 arcmin in declination);

Distance of HR7728 from the Sun and relative movement

HR7728 is distant 851.17 light years from the Sun and it is moving towards the Sun at the speed of 14 kilometers per second.

261.10 pc
851.17 ly
-14 km/s
0.009 arcsec/year
-0.042 arcsec/year

Spectral properties of HR7728

HR7728 belongs to spectral class M4 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where HR7728 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR7728. Attribution: Richard Powell / CC BY-SA

HR7728 star system properties

HR7728 is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the HR7728 double sysyem:

38 arcsec

Alternative designations of HR7728