Theta Ceti is a solitary, orange-hued star in the equatorial constellation of Cetus. Its name is a Bayer designation that is Latinized from ø Ceti, and abbreviated Theta Cet or ø Cet. This star is visible to the naked eye with an apparent visual magnitude of 3.60. Based upon an annual parallax shift of as seen from Earth, it is located about from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.28 due to interstellar dust. The star is drifting further away with a line of sight velocity component of +17 km/s.
With an age of about 2.2 billion years, this is an evolved, K-type giant star with a stellar classification of K0 III. It is a red clump star on the horizontal branch, which means it is generating energy through helium fusion at its core. The star has an estimated 1.8 times the mass of the Sun and has expanded to 10 times the Sun's radius. It is radiating 58 times the solar luminosity from its photosphere at an effective temperature of 4,951 K.
In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Thanih al Naamat (ëçÃÂàçÃÂÃÂùçàçê - thÃÂnë al-naýÃÂmÃÂt), which was translated into Latin as Secunda Struthionum, meaning the second ostrich. This star, along with ÷ Cet (Deneb Algenubi), àCet (Thalath Al Naamat), ö Cet (Baten Kaitos) and àCet, were Al NaýÃÂmÃÂt (çÃÂÃÂùçàçê), the Hen Ostriches.
In Chinese, (), meaning Square Celestial Granary, refers to an asterism consisting of ø Ceti, ù Ceti, ÷ Ceti, ö Ceti, àCeti and 57 Ceti. Consequently, the Chinese name for ø Ceti itself is (, ).