* Astronomy

Defiant · C

RE: Eta Cassiopeiae

Blobrana · L

Estimates provided by the NASA Star and Exoplanet Database indicate that the inner edge of Eta Cassiopeiae's habitable zone could be located around 0.90 AU from the star, while the outer edge edge lies around 1.80 AUs. The distance from Star A where an Earth-type planet could have liquid water on its surface is centered around 1.35 AU -- between Earth's and somewhat short of Mars' orbital distance of 1.5 AUs in the Solar System. At that distance from Star A and assuming that it has 1.1 Solar-mass, such a planet would have an orbital period of just under 1.5 years.
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Blobrana · L

Eta Cassiopeiae is a star system 19.4 light years away from Earth, in the constellation Cassiopeia. Sometimes the traditional name Achird is used.
The primary star in the Eta Cassiopeiae system is a yellow dwarf (main sequence) star of spectral type G0V, putting it in the same spectral class as our Sun, which is of spectral type G2V. It therefore resembles what our Sun might look like if we were to observe it from Eta Cassiopeiae. The star is of apparent magnitude 3.45. The star has a cooler and dimmer (magnitude 7.51) orange dwarf companion of spectral type K7V. The system is an RS Canum Venaticorum type variable star and its brightness varies by 0.05 magnitudes.
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