38 Geminorum

Characteristics

The primary component, e Geminorum Aa, is an A-type main-sequence star which has about 1.61 times the mass of the Sun, 1.97 times the radius of the Sun and an effective temperature of 7,150 K. It is a suspected chemically peculiar star of subtype CP1 (an Am star), which Slettebak (1955) classified as kA8mF0Vp. This notation indicates the star displays the calcium K line of an A8 star and the metal lines of an F0V star. In 1949, J. Hopmann catalogued it as a suspected Delta Scuti variable.

The primary is closely orbited by companion e Geminorum Ab, which is a smaller F-type main-sequence star with 1.16 times the radius of the Sun and a temperature of 6,300 K. It can explain the X-ray emission coming from the system. The system has been resolved using interferometry, which obtained an projected separation of 0.44 au. Combined with the masses, this results in an estimated orbital period of about two months.

The Aa-Ab system is orbited by the component B, which has a projected separation of . Two sets of low quality orbital elements have been computed for this system, yielding periods of 709980 days and 1165000 days, and eccentricities of 0.150 and 0.485, respectively. As of 2018, the pair had an angular separation of (implying a projected separation of 220 au) along a position angle of 143°. Star B is a G-type main-sequence star with a class of G6V, 0.95 times the Sun's mass, 0.89 times the Sun's radius and an estimated effective temperature of 5,583 K.

The most distant component, UPM J0654+1310, has a projected separation of 4,560 au and is believed to be a red dwarf with a mass of just .

References

| display-authors=1 | journal=Astrophysical Journal

| display-authors=1 | last1=Gáspár | first1=András | doi-access=free

| display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society

| display-authors=1 | last1=Mason | first1=B. D.

References

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