Final Pt 3 Flashcards
The transit probability for an exoplanet depends on the _____ of the star, and planet, and the ___ between them
radius, distance
The Kepler mission launched on march 7 in 2009, shows that _____% of visible stars are likely to have ___, possibly ___ planets similar in size to earth and located within the __ ___ of their parent stars. Kepler’s sole scientific instrument is a _____ that continually monitors the brightness of approximately _____ main sequence stars (transits)
20-50, small, rocky, habitable zone, photometer, 150,000
The initial doppler discovery of many hot jupiters was a ____ sample
biased
Comparing the average density of exoplanets to the density of planets in our solar system helps us to understand whether they are ___ or ___ in nature
rock, gaseous
The first planetary system was found around the star ___ ___ in 1999 using the ____ method. This was both the first multiple-planet system to be discovered around a ______ star and the first multiple planet system known in a _____ system. Many others have been found since then. Many planetary systems have only ___ known planets but few have as many as ___. The ___ ___ ____ affect habitable zones.
upsilon andromedae, doppler, main sequence, multiple-star, 2, 5, stellar effective temperature
Extrasolar planetary systems have objects that we didn’t see in the solar system. For example, the very close-in massive planets, ____ ____, or the very close-in smaller planets, ___ ____ to ____. ____ ____ also exist. We also find extrasolar planets in ____ with each other.
hot jupiters, hot neptunes, earths, super earths, resonance
______ ___ was discovered in 1995 by radial velocity, It has a ____ day orbit, and a minimum mass ____x that of jupiter. It is _____°C and puffy. It was first thought to be ____ but now it is known it is numerous, and prompted theories of ___ ____
pegasi b, 4, 0.5, 950, anomalous, orbital migration
The formation of hot jupiters at their current locations is ______. In models of core _____, both the available disk mass and the opening of __ ___ appear to preclude their growth.
unlikely, accretion, disk gaps
Inward orbital migration is due to the ___ ____ with gas disks or _____ ____ which would naturally bring planets inward from their ___ ____.
gravitational interactions, planetesimal disks, formation sites
When two planets _____ gravitationally, they end up on ___ orbits that are circularized by ______ at the periastron.
scatter, eccentric, tides
The effect of tidal forces between a body in orbit around a central celestial object, whereby the eccentricity of the orbit is reduced over time so that it becomes less and less elliptical
tidal circularization
Arise when two orbiting bodies exert a regular, periodic gravitational influence on each other as a result of simple numerical relationship between frequencies or periods
orbital resonances
In orbital resonance, the ___ ___ between two bodies does not average to ____ over long time scales. this means the gravitational influences occur always at the same time, and are not ____. Exoplanet resonances must be ____.
repetitive force, zero, random, stable
Gaps occurs where asteroids would have ___ ___ that are simple fractions of jupiter’s ___ year period, giving clues to ___ ____ ____
orbital periods, 12, mean motion resonance
Current observations of transiting or ___ ____ systems typically do not allow definitive assignment to mean motion resonance. A common practice is to use ___ ___ ____ as a proxy for resonance. For example, the frequent occurrence of Kepler systems with ratios of ___ , ____, and ____, even if not strictly resonant orbits gives hints of information
radial velocity, orbital period ratios, 2:1, 3:1, 3:2
Planets change orbits during their evolution with both their ___ ___ and _____ changing. For a sufficiently slow migration, the final state depends only on the ratio of the ___ times. For high migration rates, ___ ___ is suppressed. Depending on how the migration proceeds, planets can either be trapped or not in specific resonances
semimajor axis, eccentricity, e-folding, resonant capture
You can get direct observable evidence of the planetary material (_____) outside of our solar system by observing ___ ___ ____. Cool white dwarves normally only show ___ or ___ lines
planetesimals, accreting white dwarves, H, He
Unstable resonances have conjunctions where both planets are at their _____ to the star. This will cause their orbits to ____ ___
pericenters, drive away
stable resonances occur when two planets are closest at both at their ______, or when one planet is at their ___ and one planet is at their ___ from the sun.
apocenter, apocenter, pericenter
The derivation of ____ orbital elements which match the ____ for a multi-planet system, as derived from either ____ or ___ fitting does not guarantee that the resulting orbits are ___ over long periods of time. The best fitting solution might, for example, describe an unstable system which would swiftly disintegrate through ____ of one of the planets, or by causing two of the planets to _____.
keplerian, observables, kinetic, dynamic, stable, ejection, collide
The two planet system ____ ___, with an age of ____ Gyr, has a best fit orbit that predicts that one of the two planets will either be ____ or ___ with the star within _____ years. In 2001, the star was found to contain an unusually high amount of _____. One or more of the planets may have fallen into the star, sometime after it passed through its early ____ stage. ___ ___ analysis hints at the presence of a third jovian planet.
HD 82943, 2.9, ejected, collide, 100,000, lithium-6, evolutionary, radial velocity
the irregular behaviour that can occur in deterministic dynamic systems
chaos
Upsilon andromedae is a ____ ___ system consisting of a star slightly more massive than the sun and a ___ ____. ___ jupiter mass planets orbit the more massive star
binary star, red dwarf, 4
a robust formation mechanism must explain not only the ____ properties of the solar system, but also the ____ ____ and ___ distribution, including their frequently large ____. Particular challenges are posed by the large number of close-in planets with a < ____ AU where high temperatures and relatively small amount of ____ ___ would preclude accretion _____ ___
observable, exoplanet frequency, mass, eccentricies, 0.2, protostellar matter, in situ
