Sentences with phrase «stellar radius»

From high - resolution spectroscopy of the star we estimate a stellar effective temperature of Teff = 6100 + / - 150 K, and from high - precision z and B photometry of the transit we constrain the ratio of the semi-major axis and the stellar radius to be a / R = 6.03 + / - 0.13.

Based on this estimate and the photometric time series, we constrain the stellar radius to be R * = 1.738 + / - 0.092 Rsun and the planet radius to be Rp = 1.674 + / - 0.094 RJup.

Once observations of the moment of inertia will be possible through the measurement of binary pulsars, the new method will allow us to measure the stellar radius with a precision of 10 % or less.

The tiny spacecraft would first need to approach the star Alpha Centauri A as close as around four million kilometres, corresponding to five stellar radii, at a maximum speed of 13,800 kilometres per second (4.6 per cent of the speed of light).

Ultra-diffuse galaxies (UDGs) are notable for their extreme low surface brightness nature and extended radii; they have the stellar mass and appearance of dwarf spheroidal galaxies but the stellar radii of larger galaxies like the Milky Way.

These stellar radii and masses are in turn used to redetermine the transiting planet radii and masses, again using only direct observables.

The improved stellar radii enable improved planet radii.

For Kepler - 20c and Kepler - 20d, the blend scenario is independently disfavored by the achromaticity of the transit: From Spitzer data gathered at 4.5 um, we infer a ratio of the planetary to stellar radii of 0.075 + -0.015 (Kepler - 20c) and 0.065 + -0.011 (Kepler - 20d), consistent with each of the depths measured in the Kepler optical bandpass.

Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13 solar radii (39 %) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs.

We measure equivalent widths of spectral features, derive calibration relations using stars with interferometric measurements, and estimate stellar radii, effective temperatures, masses, and luminosities for the K2 planet hosts.

The median uncertainties on the stellar radii and masses are ~ 8 % and ~ 30 %, respectively, and the resulting uncertainties on the planet radii and masses are ~ 9 % and ~ 22 %, respectively.

Not exact matches

The researchers modeled the resulting accretion disc — an elliptical disc of stellar debris swirling around the black hole — along with its probable speed, radius, and rate of infall, or speed at which material falls onto the black hole.

The findings, published online April 29 in Physical Review Letters, could help scientists measure the mass and radius of these unusual stellar bodies, and thereby gain insights into the physics of matter at extreme densities.

The Gemini «speckle» data directly imaged the system to within about 400 million miles (about 4 AU, approximately equal to the orbit of Jupiter in our solar system) of the host star and confirmed that there were no other stellar size objects orbiting within this radius from the star.

Specifically, eclipsing binary stars can be used to study the stellar mass - radius relationship and to test predictions of theoretical stellar evolution models.

Assuming a Jupiter - like composition, its radius is projected to be about 1.2 times that of Jupiter, enlarged relative to Jupiter because of greater absorbed stellar radiation in its inner orbit.

By combining the stellar masses from the ETV study with the simultaneous light curve analysis we determine the absolute radii of the three stars.

«These fundamental properties are used to determine the stellar mass and radius allowing for precise determination of the planet size,» said Howard Isaacson, researcher in the astronomy department at UC Berkeley and mamba of the discovery team.

«With the precise stellar parameters from the HIRES spectrum, we can show that planet radius is closer to the size of the Earth, than say Neptune (~ 4x Earth's radius).

We then reassess the radii and equilibrium temperatures of known and candidate planets based on our spectroscopically derived stellar parameters.

These parallactic mass and radius measurements have uncertainties small enough that they may provide observational input into the stellar models themselves.

We find that, for optically thick disks, CO inner radii are strongly correlated with the total system luminosity (stellar plus accretion), and consistent with the dust sublimation radius.

It is a solar - like main - sequence star with a similar yellowish colour, [31] whose stellar classification is spectral type G2 V. From the determined mutual orbital parameters, Alpha Centauri A is about 10 percent more massive than the Sun, with a radius about 22 percent larger.

The radius of the event horizon is called the Schwarzschild radius, after the German astronomer Karl Schwarzschild, who in 1916 predicted the existence of collapsed stellar bodies that emit no radiation.

The dilution of the host star's light by the nearly equal magnitude stellar companion (~ 0.5 magnitudes fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10 % and 60 %, respectively.

The dilution of the host star's light by the nearly equal magnitude stellar companion (~ 0.5 magnitudes fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10 %... ▽ More We present the discovery of a hot Jupiter transiting an F star in a close visual (0.3» sky projected angular separation) binary system.

However, the validity of the scaling relations depends on the homology between the star under study and the r... ▽ More The scaling relations between global asteroseismic observables and stellar properties are widely used to estimate masses and radii of stars exhibiting solar - like oscillations.

Determinations of surface gravity ($ \ log -LCB- g -RCB- $), mean density ($ \ rho $), radius ($ R$), mass ($ M$), and age ($ \ tau $) for the whole sample have been carried out with stellar grid - based modeling.

We demonstrate that the combination of observations from GAIA and PLATO will allow us to tightly constrain stellar masses, ages and radii with machine learning for the purposes of Galactic and planetary studies.

A comparison with stellar properties in the planet - candidate catalog by Batalha et al. shows that radii for subgiants and giants obtained from spectroscopic follow - up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement.

Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant - planet / brown - dwarf / stellar regime to a sub-Jupiter size, or vice versa.

The cluster members are therefore expected to have s... ▽ More Stellar mass $ M$, radius $ R$, and gravity $ g $ are important basic parameters in stellar pStellar mass $ M$, radius $ R$, and gravity $ g $ are important basic parameters in stellar pstellar physics.

In particular, planets orbiting inside the stellar wind Alfvén radius can magnetically influence their host star and sometimes influence the angular momentum evolution of the system.

These relations provide a direct link between observables, i.e. effective temperature and characteristics of the oscillation spectra, and stellar properties, i.e. mean density and surface gravity (thus mass and radius).

Abstract: The scaling relations between global asteroseismic observables and stellar properties are widely used to estimate masses and radii of stars exhibiting solar - like oscillations.

We obtain median uncertainties in stellar age, mass, and radius of 14.8 %, 3.6 %, and 1.7 %, respectively.

The short fallback time derived from the light curve requires an ultra-close encounter where the pericentre of the stellar orbit is deep within the tidal disruption radius.

Assuming a Jupiter - like composition, its radius may be about 1.2 times that of Jupiter, enlarged relative to Jupiter because of greater absorbed stellar radiation in its inner («torch») orbit.

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).