Diphda

Cetus β Ceti HR 188 2.04ᵐ

Place on the Hertzsprung-Russell diagram

a giant · 113 times brighter than the Sun in visible light · 8 640 catalogue stars behind it

Data

Constellation
Cetus
Apparent magnitude
2.04
№9044 / 9096
Absolute magnitude
-0.30
№5658 / 8923
Distance
96 light years
№8390 / 8923
Temperature
4 695 K
№6241 / 8786
Spectral class
G9.5IIICH-1
Proper motion
0.236 ″/ years
№516 / 9092
Radial velocity
13 km/s
Right ascension
10.8975 °
Declination
-17.9867 °
Catalogue numbers
HR 188 · HD 4128

Origin of the name

From the Arabic al-ḍifda‘ al-thānī, "the second frog"; the first was Fomalhaut.

What kind of star this is

A giant: the core hydrogen is spent, the star has swollen tens of times over and cooled at the surface while staying far brighter than the Sun — luminosity comes from area, not from temperature. Ahead of it lies the shedding of its outer layers as a planetary nebula, and a cooling core the size of the Earth: a white dwarf.