Frequency of Planets in Binaries. (arXiv:2002.11734v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bonavita_M/0/1/0/all/0/1">Mariangela Bonavita</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Desidera_S/0/1/0/all/0/1">Silvano Desidera</a>
The frequency of planets in binaries is an important issue in the field of
extrasolar planet studies because of its relevance in the estimation of the
global planet population of our galaxy and the clues it can give to our
understanding of planet formation and evolution. Multiple stars have often been
excluded from exoplanet searches, especially those performed using the radial
velocity technique, due to the technical challenges posed by such targets. As a
consequence and despite recent efforts, our knowledge of the frequency of
planets in multiple stellar systems is still rather incomplete. On the other
hand, the lack of knowledge about the binarity at the time of the compilation
of the target samples means that our estimate of the planet frequency around
single stars could be tainted by the presence of unknown binaries, especially
if these objects have a different behavior in terms of planet occurrence. In a
previous work we investigated the binarity of the objects included in the
Uniform Detectability sample defined by Fisher and Valenti (2005), showing how
more than 20% of their targets were, in fact, not single stars. Here, we
present an update of this census, made possible mainly by the information now
available thanks to the second Gaia Data Release. The new binary sample
includes a total of 313 systems, of which 114 were added through this work. We
were also able to significantly improve the estimates of masses and orbital
parameters for most of the pairs in the original list, especially those at
close separations. A few new systems with white dwarf companions were also
identified. The results of the new analysis are in good agreement with the
findings of our previous work, confirming the lack of difference in the overall
planet frequency between binaries and single stars but suggesting a decrease in
the planet frequency for very close pairs.}
The frequency of planets in binaries is an important issue in the field of
extrasolar planet studies because of its relevance in the estimation of the
global planet population of our galaxy and the clues it can give to our
understanding of planet formation and evolution. Multiple stars have often been
excluded from exoplanet searches, especially those performed using the radial
velocity technique, due to the technical challenges posed by such targets. As a
consequence and despite recent efforts, our knowledge of the frequency of
planets in multiple stellar systems is still rather incomplete. On the other
hand, the lack of knowledge about the binarity at the time of the compilation
of the target samples means that our estimate of the planet frequency around
single stars could be tainted by the presence of unknown binaries, especially
if these objects have a different behavior in terms of planet occurrence. In a
previous work we investigated the binarity of the objects included in the
Uniform Detectability sample defined by Fisher and Valenti (2005), showing how
more than 20% of their targets were, in fact, not single stars. Here, we
present an update of this census, made possible mainly by the information now
available thanks to the second Gaia Data Release. The new binary sample
includes a total of 313 systems, of which 114 were added through this work. We
were also able to significantly improve the estimates of masses and orbital
parameters for most of the pairs in the original list, especially those at
close separations. A few new systems with white dwarf companions were also
identified. The results of the new analysis are in good agreement with the
findings of our previous work, confirming the lack of difference in the overall
planet frequency between binaries and single stars but suggesting a decrease in
the planet frequency for very close pairs.}
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