«This is the widest range of
orbital radii of any planetary system known,» Marois told New Scientist.
For an object so big, these flashes are extremely short, implying a radiating surface about the same as a sphere with
orbital radius of Jupiter.
The emission fits a model with a grain temperature of 40 K, indicating a minimum
orbital radius of 60 AU from the host star.
The radius corresponds to 10 times
the orbital radius of Neptune in our solar system.
Not exact matches
Orbital radius of such star should be about 33 astronomical units, the
orbital length should then exceed two hundred astronomical units.»
They eliminated those with
orbital radii less than one tenth that
of Earth's, because at that distance moon systems might not remain in stable orbits around their planets on billion - year timescales.
Their models showed that if you visited any star with a planet orbiting from the same distance as Earth down to one tenth that, there is about a 38 percent chance (and likely less) that you would run into a planet and moon system similar to Jupiter's four Galilean satellites (Io, Europa, Ganymede and Callisto), with similar ratios
of moon to planetary diameters and
orbital to planetary
radii.
The planet is extremely close to its star — its
orbital radius is only about three times the
radius of the star — and the scientists have estimated that its surface temperatures may be as high as 3,000 degrees Kelvin, or more than 5,000 degrees Fahrenheit.
This chart shows, on the top row, artist concepts
of the seven planets
of TRAPPIST - 1 with their
orbital periods, distances from their star,
radii and masses as compared to those
of Earth.
A simulation (Wolf & D'Angelo 2005)
of ALMA observations at 950 GHz
of a disc shows an embedded protoplanet
of 1 Jupiter Mass around a 0.5 Solar Mass star (
orbital radius: 5AU).
A subsequent analysis using the most recent kinematic and radial velocity data available in the literature, however, found Proxima «is quitely likely» to be bound to to Stars A and B based on calculations
of the binding energy
of Proxima relative to the center
of mass
of the entire triple system, where its
orbital semi-major axis exceeds 10,000 AUs and is «on order the same size as Alpha Centauri AB's Hill
radius in the galactic potential» (Wertheimer and Laughlin, 2006).
Through ACCESS, we are compiling a library
of exoplanet transmission spectra, which will ultimately enable us and the wider exoplanet atmosphere community to study trends in the atmospheric properties
of exoplanets as they relate to the exoplanets» masses,
radii, and
orbital parameters.
On the other hand, stars Aa and Ab have are separated by only 3.76 solar
radii, which is about 14.9 times the
radius of CM Draconis Aa (Claud H. Lacy, 1977), and have a mutual
orbital period
of just under 1.27 days (Deeg et al, 1998; Metcalfe et al, 1996; and Claud H. Lacy, 1977).
Our new -LCB- \ em Spitzer -RCB- observations were taken two years after the original K2 discovery data and have a significantly higher cadence, allowing us to derive improved estimates for this planet's
radius, semi-major axis, and
orbital period, which greatly reduce the uncertainty in the prediction
of near future transit times for the -LCB- \ em James Webb Space Telescope -RCB--LRB--LCB- \ em JWST -RCB--RRB- observations.
This study examines planet occurrence rates for the Kepler GK dwarf target sample for planet
radii, 0.75 < Rp < 2.5 Rearth, and
orbital periods, 50 < Porb < 300 days, with an emphasis on a thorough exploration and identification
of the most important sources
of systematic uncertainties.
We find that 16.5 + / - 3.6 %
of main - sequence FGK stars have at least one planet between 0.8 and 1.25 Earth
radii with
orbital periods up to 85 days.
Based on the star's mass and the period
of the shift, we can also calculate the planet's
orbital radius.
Results from just forty - three days
of data along with ground - based follow - up observations have identified five new transiting planets with measurements
of their masses,
radii, and
orbital periods.
Detailed modeling
of the transit is consistent with a planetary companion with an
orbital period
of 3.548460 + / -0.000032 days and a
radius of 1.431 + / -0.050 Rj.
Multiple planets transiting the same star reveal more: period ratios determine stability and dynamics, mutual gravitational interactions reflect planet masses and
orbital shapes, and the fraction
of transiting planets obs... ▽ More When an extrasolar planet passes in front
of its star (transits), its
radius can be measured from the decrease in starlight and its
orbital period from the time between transits.
Abstract: When an extrasolar planet passes in front
of its star (transits), its
radius can be measured from the decrease in starlight and its
orbital period from the time between transits.
They examined how the
orbital distances
of their final sample are related to the planetary mass and / or the planetary
radius, depending on which measurements are available.
Indeed, stable orbits may extend as far as one third
of the closest separation between any two stars in a binary system, but according to NASA's Kepler Mission team, numerical integration models have shown that there is a range
of orbital radii between about 1/3 and 3.5 times the stellar separation for which stable orbits around two stars are not possible (Holman and Wiegert, 1999; Wiegert and Holman, 1997; and Donnison and Mikulskis, 1992).