Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]

Polis - μ Sagittarii (mu Sagittarii)

Polis, also designated as μ Sagittarii (mu Sagittarii), is a variable and multiple supergiant star in the constellation of Sagittarius.

Polis visual magnitude is 3.86. Because of its moderate brightness, Polis 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 Polis:

3.86
Supergiant
Polis - μ Sagittarii (mu Sagittarii) is below the horizon from Greenwich, United Kingdom [change].

Celestial coordinates and finder chart of Polis

Polis is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Polis are provided in the following table:

18h 13m 45s
-21° 03’ 32”
10°
-1.6°
Sagittarius

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

Finder chart Polis - μ Sagittarii (mu Sagittarii) star
Simplified finder chart for Polis - μ Sagittarii (mu Sagittarii).

Visibility of Polis from your location

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

Today's Polis - μ Sagittarii (mu Sagittarii) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 111.1°
Max altitude: 17.5°
Azimuth: 248.9°
Polis - μ Sagittarii (mu Sagittarii) is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of Polis

The image below is a photograph of Polis 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 Polis is 0.002 arcsec per year in Right Ascension and 0.001 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of Polis - μ Sagittarii (mu Sagittarii) star
DSS2 image of Polis. The red arrow shows the motion of Polis during the next 100000 years (3.33 arcmin in Right Ascension and 1.67 arcmin in declination);

Distance of Polis from the Sun and relative movement

Polis is distant 29,636.36 light years from the Sun and it is moving towards the Sun at the speed of 6 kilometers per second.

9,090.91 pc
29,636.36 ly
-6 km/s
0.002 arcsec/year
0.001 arcsec/year

Spectral properties of Polis

Polis belongs to spectral class B8 and has a luminosity class of I corresponding to a supergiant star.

-10.93
B8I
7938K

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

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

Polis star system properties

Polis 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 Polis double sysyem:

3.86
6.76
2.9
0 arcsec

Alternative designations of Polis

Polis
μ Sagittarii
(mu Sagittarii)
13 Sagittarii
SAO186497
SAO186497