Gamma Serpentis

Gamma Serpentis is a main sequence dwarf star of spectral and luminosity type F6 V, but it is still listed as a subgiant in some catalogues. The star may have around 1.15 to 1.27 times Sol's mass (Bi et al, 2008; Takeda et al, 2004; Caliskan et al, 2002; NASA Stars and Exoplanet Database; and David F. Gray, 1992), around 1.37 +/- 0.06 times Sol's diameter based on a power-law estimate (NASA Stars and Exoplanet database; and Kenneth R. Lang, 1980); and around 3 times its visual luminosity and perhaps around 2.74 +/- 0.04 times its theoretical bolometric luminosity (NASA Stars and Exoplanet database; and Kenneth R. Lang, 1980). It may be around 1.6 to 3.4 billion years old (Trilling et al, 2007; Chen et al, 2006; Bryden et al, 2006; Nordstrom et al, 2004; and Edvardsson et al, 1993, page 124 for HR 5933). The star may only be around 40 to 85 percent as enriched as Sol with elements heavier than hydrogen ("metallicity") based on its abundance of iron (Takeda et al, 2004; Chen et al, 2001; Carretta et al, 2000; and Cayrel de Strobel et al, 1991, page 299). With an active chromosphere and a fast rotational period of around three days (Cumming et al, 1999, page 902, Table 7 as HR 5933), it has been designated NSV 7350 as a New Suspected Variable star. Useful star catalogue numbers for the star include: Gam Ser, 41 Ser, HR 5933, Gl 603, HIP 78072, HD 142860, BD+16 2849, SAO 101826, FK 591, LHS 408, LTT 14730, and LFT 1234.

In observations with the 1983 Infrared Astronomical Satellite (IRAS) mission, a shell of cool dust around 9.5 micronmeters was detected at an "equilibrium distance" of 25.9 AUs from Gamma Serpentis (within its "planet-forming region"), which may be related to a ring of large dust particles at an orbital distance that was previously calculated somewhat "subjectively" to be around 19 AUs (Rautela et al, 1990, pp. 14-15; and Hartmut Hans-Georg Aumann, 1985, page 890). More recent detections of infrared excess from particles of 60 micrometers in size have been detected with the Spitzer Space Telescope (Chen et al, 2006; and Bryden et al, 2006). The cold dust is found at the outer orbital distances that would appear to be related to collisions between Edgeworth-Kuiper Belt type bodies studied in the Solar System.

The Washington Double Star (WDS) catalog lists two companions (WDS 15565+1540STT 584AB and 584BC, or WDS J15565_1540 B and C) over three arc-minutes away from Gamma Serpentis. These appear to be optical companions only. The star was also suspected of having a spectroscopic companion which was not confirmed by radial-velocity variations (Cumming et al, 1999; and Duquennoy and Mayor, 1991, page 492 for Gl 603).