相关论文: Demonstrating the Elliptical Orbit of Mars using N…

The dynamics of Mars' obliquity are believed to be chaotic, and the historical ~3.5 Gyr (late-Hesperian onward) obliquity probability density function (PDF) is high uncertain and cannot be inferred from direct simulation alone. Obliquity is…

Context: The orientation and rotation of Mars, which can be described by a set of Euler angles, is estimated from radioscience data and is then used to infer Mars internal properties. The data are analyzed using a modeling expressed within…

Prior to the invention of the telescope many astronomers worked out theories of the motion of the Moon. The purpose of such theories was to be able to predict the position of the Moon in the sky. These geometrical models implied a certain…

Ptolemy's model of the Moon's motion implied that its distance varies by nearly a factor of two, implying that its angular size should also vary by nearly a factor of two. We present an analysis of 100 naked eye observations of the Moon's…

Mapping exoplanets across phases and during secondary eclipse is a powerful technique for characterizing Hot Jupiters in emission. Since these planets are expected to rotate about axes normal to their orbital planes, with rotation periods…

The Mars Reconnaissance Orbiter (MRO) spacecraft has been in orbit around Mars since March 2006. The Context Camera (CTX) on MRO has returned over 100,000 images of the planet at approximately 5-6 meters per pixel, providing nearly global…

The 30 year orbit of the Cepheid Polaris has been followed with observations by the CHARA Array (Center for High Angular Resolution Astronomy) from 2016 through 2021. An additional measurement has been made with speckle interferometry at…

We investigate potential biases in the measurements of exoplanet orbital parameters obtained from radial velocity observations for single-planet systems. We create a mock catalog of radial velocity data, choosing input planet masses,…

The Mars Express (MEX) mission has been successfully operated around Mars since 2004. Among many results, MEX has provided some of the most accurate astrometric data of the two Mars moons, Phobos and Deimos. In this work we present new…

Can a machine or algorithm discover or learn the elliptical orbit of Mars from astronomical sightings alone? Johannes Kepler required two paradigm shifts to discover his First Law regarding the elliptical orbit of Mars. Firstly, a shift…

Planets in highly eccentric orbits form a class of objects not seen within our Solar System. The most extreme case known amongst these objects is the planet orbiting HD~20782, with an orbital period of 597~days and an eccentricity of 0.96.…

The examination of long-term (1979-2020) photometric observations of SS433 enabled us to discover a non-zero orbital eccentricity of $e=0.05\pm 0.01.$ We have also found evidence for a secular increase in the orbital period at a rate of…

Using 25 years of data from uninterrupted monitoring of stellar orbits in the Galactic Center, we present an update of the main results from this unique data set: A measurement of mass of and distance to SgrA*. Our progress is not only due…

The rotation and orientation of Mars is commonly described using two different sets of angles, namely the Euler angles wrt the Mars orbit plane and the right ascension, declination, and prime meridian location angles wrt the Earth equator…

We used recently produced Solar System ephemerides, which incorporate two years of ranging observations to the MESSENGER spacecraft, to extract the secular orbital elements for Mercury and associated uncertainties. As Mercury is in a stable…

As space exploration extends into cislunar space and further towards Mars, understanding the relativistic effects on clocks on Mars, particularly in relation to multibody gravitational influences, becomes increasingly important for accurate…

Summed many years of work at Pulkovo, the orbits of 67 wide pairs of visual double and multiple stars (included in 64 systems) which were obtained by the Apparent Motion Parameters (AMP) method are presented. This short arc determination…

The eccentricity of a planet's orbit and the inclination of its orbital plane encode important information about its formation and history. However, exoplanets detected via direct-imaging are often only observed over a very small fraction…

For a hypothetical planet on a highly eccentric orbit, we have calculated the osculating orbital parameters and its closest approaches to Earth and Moon over a period of 750 kyr. The approaches which are close enough to influence the…

Observations of nine transits of WASP-107 during the {\it K2} mission reveal three separate occasions when the planet crossed in front of a starspot. The data confirm the stellar rotation period to be 17 days --- approximately three times…