A-type star · white star
21 Cas
21 Cas is a white star in the constellation Cassiopeia 303 ly from Earth. Its surface is about 9,246 K, about 1.6 times the Sun's surface temperature, and it shines at 41.80× the Sun's brightness. At magnitude 5.6 it is bright enough to see with the naked eye; the light you see left it 303 years ago.
Also catalogued as HR 192 · HD 4161 · HIP 3572
9,246 K
temperature
5.64
apparent magnitude
41.80× ☉
luminosity vs Sun
A2IV
spectral type
Distance & comparison with our Sun
303 years
at light speed from Earth
1.60×
as hot as the Sun
41.80×
the Sun's light output
0.80
absolute magnitude
Explore from here · roam the neighborhood
Nearest stars
Can you see it tonight?
VISIBLE TO THE NAKED EYE
Star data from the HYG database v4.2 (Astronexus, CC BY-SA 4.0). Temperature and colour computed by gravityfinder from the B-V colour index; the illustration is generated from that temperature, not a photograph.