Nunki - σ Sagittarii (sigma Sagittarii)
Nunki, also designated as σ Sagittarii (sigma Sagittarii), is a double main-sequence star in the constellation of Sagittarius.
Nunki visual magnitude is 2.02, making it the 50th brightest star in the sky. Thanks to its high brightness, Nunki is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.
The table below summarizes the key facts about Nunki:
Celestial coordinates and finder chart of Nunki
Nunki is situated south of the celestial equator, as such, it is more easily visible from the southern emisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Nunki are provided in the following table:
The simplified sky map below shows the position of Nunki in the sky:
Visibility of Nunki from your location
Digitized Sky Survey image of Nunki
The image below is a photograph of Nunki 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 Nunki is 0.013 arcsec per year in Right Ascension and -0.054 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.
Distance of Nunki from the Sun and relative movement
Nunki is distant 224.21 light years from the Sun and it is moving towards the Sun at the speed of 11 kilometers per second.
Spectral properties of Nunki
Nunki belongs to spectral class B2 and has a luminosity class of V corresponding to a main-sequence star.
The red dot in the diagram below shows where Nunki is situated in the Hertzsprung–Russell diagram.
Nunki star system properties
Nunki 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 Nunki double sysyem: