Our latest paper on spectroscopy of compact triples is out.

A new work focusing on spectroscopy of new compact triple systems is finally out in Astronomy and Astrophysics.

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We have estimated the masses, radii, temperatures, metallicities, and ages of 12 stars in four CHTs. Some interesting results include the CHT CD-32 6459 which shows signs of von Zeipel-Lidov-Kozai oscillations, while the system CD-62 1257 is a candidate to form a triple common envelope.

One of the interesting part of the paper is where we combined observations of masses, outer eccentricities (e2), orbital periods, and age estimates of the systems from the literature. We then compared the distributions of e2, and the tertiary mass ratio, q3 = M3/(M1 + M2), for three different metallicity ranges and two age ranges. We find that the q3 distribution for CHTs with sub-solar metallicity has a uniform distribution but the systems with solar and above-solar metallicity peak between 0.5 and 1. When dividing them according to their ages, we find the q3 of old systems to be around 0.5. The eccentricity, e2, favours a value of around 0.3 irrespective of metallicity or age.

This shows that compact triples are formed like close binaries but some of the distributions of orbital parameters are affected by dynamic mechanism which we are yet to identify.