Planet Formation in Binary Systems

Among the 50 discovered extrasolar planets orbiting main-sequence solar type stars only three are confirmed to be in a binary star system. However, the majority of stars seem to form in binary or even multiple stellar systems. Standard planet formation scenarios consider the creation of planets or planetary systems only for isolated solitary stars. The presence of a companion creates tidal torques on the protoplanetary disk, which may influence the formation process of planets in disks. In this contribution the consequences of the companion's perturbation on the formation scenario of planets is briefly discussed.

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A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary

Science ◽

10.1126/science.1251527 ◽

2014 ◽

Vol 345 (6192) ◽

pp. 46-49 ◽

Cited By ~ 57

Author(s):

A. Gould ◽

A. Udalski ◽

I.-G. Shin ◽

I. Porritt ◽

J. Skowron ◽

...

Keyword(s):

Binary Systems ◽

Planet Formation ◽

Binary Star ◽

Terrestrial Planet ◽

Search Strategies ◽

The Sun ◽

Star System ◽

Low Mass ◽

Formation And Evolution ◽

Binary Star System

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth’s) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet’s temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

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Computer simulation of planet formation in a binary star system: Terrestrial planets

The Moon and the Planets ◽

10.1007/bf00897588 ◽

1980 ◽

Vol 23 (4) ◽

pp. 429-443 ◽

Cited By ~ 7

Author(s):

B. B. Djakov ◽

B. I. Reznikov

Keyword(s):

Computer Simulation ◽

Planet Formation ◽

Binary Star ◽

Terrestrial Planets ◽

Star System ◽

Binary Star System

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The first magnetic maps of a pre-main-sequence binary star system – HD 155555

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2008.13196.x ◽

2008 ◽

Vol 387 (2) ◽

pp. 481-496 ◽

Cited By ~ 21

Author(s):

N. J. Dunstone ◽

G. A. J. Hussain ◽

A. Collier Cameron ◽

S. C. Marsden ◽

M. Jardine ◽

...

Keyword(s):

Main Sequence ◽

Binary Star ◽

Star System ◽

Binary Star System

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Commission 26: Double and Multiple Stars (Etoiles Doubles Et Multiples)

Transactions of the International Astronomical Union ◽

10.1017/s0251107x00002856 ◽

2000 ◽

Vol 24 (1) ◽

pp. 186-189

Author(s):

H. Zinnecker ◽

C. Scarfe ◽

C. Allen ◽

T. Armstrong ◽

W. Hartkopf ◽

...

Keyword(s):

San Francisco ◽

Large Scale ◽

Binary Systems ◽

Extrasolar Planets ◽

Binary Star ◽

The Sun ◽

Double And Multiple Stars ◽

Nearby Stars ◽

Solar Type ◽

Low Mass

This triennial report (1996-1999) reviews the subject from a somewhat personal angle, mostly related to binary star formation and young binary star populations – a subject whose time had come in the early 1990s and is now in full swing.Many astronomers have searched for binary systems among main-sequence stars, and two large-scale surveys published in 1991 and 1992 have already become classics. Well before they became famous for finding extrasolar planets (see below), observing teams led by Michel Mayor (Geneva Observatory) and Geoffrey Marcy (San Francisco State Univ., now Univ. of Calif, at Berkeley) spent many years searching for low-mass stellar companions of nearby stars. The late Antoine Duquennoy and Mayor surveyed all solar-type dwarfs (spectral types F7 through G9) within 20 pc of the Sun, while Debra Fischer and Marcy studied stars with somewhat lower mass (M dwarfs) slightly nearer to the Sun.

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Multiplanet disc interactions in binary systems

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3175 ◽

2019 ◽

Vol 491 (4) ◽

pp. 5351-5360 ◽

Cited By ~ 4

Author(s):

Alessia Franchini ◽

Rebecca G Martin ◽

Stephen H Lubow

Keyword(s):

Binary Systems ◽

Large Range ◽

Average Rate ◽

Binary Star ◽

Orbital Plane ◽

High Mass ◽

Star System ◽

Hydrodynamical Simulations ◽

Binary Star System

ABSTRACT We investigate the evolution of a multiplanet–disc system orbiting one component of a binary star system. The planet–disc system is initially coplanar but misaligned to the binary orbital plane. The planets are assumed to be giants that open gaps in the disc. We first study the role of the disc in shaping the mutual evolution of the two planets using a secular model for low initial tilt. In general, we find that the planets and the disc do not remain coplanar, in agreement with previous work on the single planet case. Instead, the planets and the disc undergo tilt oscillations. A high-mass disc between the two planets causes the planets and the disc to nodally precess at the same average rate but they are generally misaligned. The amplitude of the tilt oscillations between the planets is larger while the disc is present. We then consider higher initial tilts using hydrodynamical simulations and explore the possibility of the formation of eccentric Kozai–Lidov (KL) planets. We find that the inner planet’s orbit undergoes eccentricity growth for a large range of disc masses and initial misalignments. For a low disc mass and large initial misalignment, both planets and the disc can undergo KL oscillations. Furthermore, we find that sufficiently massive discs can cause the inner planet to increase its inclination beyond 90° and therefore to orbit the binary in a retrograde fashion. The results have important implications for the explanation of very eccentric planets and retrograde planets observed in multiplanet systems.

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