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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: 7:43  
clear_day Transit: 11:47  
SunsetSet: 15:52 south
sleep NighttimeWhat's Visible Now?
All Constellations » Sagittarius » 

η Sagittarii (eta Sagittarii)

Altitude: -73.5°   Azimuth: 31.3°   Direction: North-North-East

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

η Sagittarii visual magnitude is 3.11. Because of its moderate brightness, η Sagittarii should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.

The table below summarizes the key facts about η Sagittarii:


η Sagittarii (eta Sagittarii) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -73.5°
Azimuth: 31.3°
Direction: North-North-East

Celestial coordinates and finder chart of η Sagittarii

η Sagittarii 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 η Sagittarii are provided in the following table:

18h 17m 37s
-36° 45’ 42”

The simplified sky map below shows the position of η Sagittarii in the sky:

Finder chart η Sagittarii (eta Sagittarii) star
Simplified finder chart for η Sagittarii (eta Sagittarii).

Visibility of η Sagittarii 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 η Sagittarii (eta Sagittarii) 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: 126.8°
Max altitude: 1.8°
Azimuth: 233.2°

Digitized Sky Survey image of η Sagittarii

The image below is a photograph of η Sagittarii 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 η Sagittarii is -0.128 arcsec per year in Right Ascension and -0.167 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of η Sagittarii (eta Sagittarii) star
DSS2 image of η Sagittarii. The red arrow shows the motion of η Sagittarii during the next 1000 years (-2.13 arcmin in Right Ascension and -2.78 arcmin in declination);

Distance of η Sagittarii from the Sun and relative movement

η Sagittarii is distant 149.06 light years from the Sun and it is moving far from the Sun at the speed of 1 kilometers per second.

45.72 pc
149.06 ly
1 km/s
-0.128 arcsec/year
-0.167 arcsec/year

Spectral properties of η Sagittarii

η Sagittarii 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 η Sagittarii is situated in the Hertzsprung–Russell diagram.

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

η Sagittarii star system properties

η Sagittarii 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 η Sagittarii double sysyem:

3.5 arcsec

Alternative designations of η Sagittarii

η Sagittarii
(eta Sagittarii)