21 Cassiopeiae is a variable and double sub-giant star in the constellation of Cassiopeia.
21 Cassiopeiae visual magnitude is 5.66. Because of its reltive faintness, 21 Cassiopeiae 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 21 Cassiopeiae:
Celestial coordinates and finder chart of 21 Cassiopeiae
21 Cassiopeiae is situated close to the northern celestial pole and, as such, it is visible for most part of the year from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of 21 Cassiopeiae are provided in the following table:
The simplified sky map below shows the position of 21 Cassiopeiae in the sky:
Visibility of 21 Cassiopeiae from your location
Location: Greenwich, United Kingdom
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
21 Cassiopeiae is circumpolar and transits at 08:19 UTC (altitude: 66.5°)
Digitized Sky Survey image of 21 Cassiopeiae
The image below is a photograph of 21 Cassiopeiae 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 21 Cassiopeiae is -0.018 arcsec per year in Right Ascension and -0.026 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.
Distance of 21 Cassiopeiae from the Sun and relative movement
21 Cassiopeiae is distant 290.04 light years from the Sun and it is moving far from the Sun at the speed of 9 kilometers per second.
Spectral properties of 21 Cassiopeiae
21 Cassiopeiae belongs to spectral class A2 and has a luminosity class of IV corresponding to a sub-giant star.
The red dot in the diagram below shows where 21 Cassiopeiae is situated in the Hertzsprung–Russell diagram.
21 Cassiopeiae star system properties
21 Cassiopeiae 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 21 Cassiopeiae double sysyem: