Gamma Pavonis

The Star

Gamma Pavonis is a yellowish-white main sequence dwarf star of spectral and luminosity type F6-8 V. This star has at least eight tenths of Sol's mass (Bell et al, 1977, page 32), a slightly larger diameter (106 +/- 11 percent of Sol's) (Perrin and Karoji, 1987, page 236) and about 1.5 times of its luminosity. The star may be only be 12 to 25 percent as enriched as Sol with elements heavier than hydrogen ("metallicity") based on its abundance of iron (Cayrel de Strobel et al, 1991, page 302). It may be over 9.1 billion years old Edvardsson et al, 1993, page 124; and NG and Bertelli, 1998), and it also has a relatively high angular momentum around the galaxy (Bell et al, 1977). A recent interpretation of these characteristics is that Gamma Pavonis is an old disk star (Axer et al, 1995, pages 754 and 756; Barbuy and Edelyi-Mendes, pages 240 and 244); and Olin Jeuck Eggen, 1973, pages 822 and 828 (1919-1998)). It is a New Suspected Variable star designated NSV 13689. Useful star catalogue numbers for the star include: Gam Pav, HR 8181, Gl 827, Hip 105858, HD 203608, CD-65 2751, CP(D)-65 3918, SAO 254999, FK5 805, LHS 3674, LTT 8510, LPM 780, and LFT 1630.

Hunt for Substellar Companions

A 2.5-year search analyzing radial velocities failed to find a large Jupiter or brown dwarf within 10 AUs of Gamma Pavonis (Murdoch et al, 1993). The orbital distance from Gamma Pavonis where an Earth-type planet would be "comfortable" with liquid water is centered around 1.2 AU -- between the orbital distances of Earth and Mars in the Solar System. At that distance from the star, such a planet would have an orbital period that is greater than an Earth year. Astronomers are hoping to use NASA's Terrestrial Planet Finder (TPF) and the ESA's Darwin planned groups of observatories to search for a rocky inner planet in the so-called "habitable zone" (HZ) around Gamma Pavonis. As currently planned, the TPF will include two complementary observatory groups: a visible-light coronagraph to launch around 2014; and a "formation-flying" infrared interferometer to launch before 2020, while Darwin will launch a flotilla of three mid-infrared telescopes and a fourth communications hub beginning in 2015.