相关论文: Seeing Earth's Orbit in the Stars: Parallax and Ab…

The question of annual stellar parallax is usually viewed as having been a "win-win situation" for seventeenth-century astronomers who subscribed to the Copernican view of universe in which the Earth orbits the Sun and the Sun is one of…

The objective reality of the Earth's motion about the Sun was finally proven observationally by Bradley (1727) when he correctly explained the ~20'' annual, elliptical motions of stars as being due to aberration of starlight caused by the…

Galileo Galilei believed that stars were distant suns whose sizes, measured via his telescope, were a direct indication of distance -- fainter stars (appearing smaller in the telescope) were farther away than brighter ones. Galileo argued…

Work published in Sky and Telescope in 2004 discusses Galileo's observations of the star Mizar. These observations raise questions regarding Galileo's assumptions about the universe and the conclusions he drew from his observations. Galileo…

The Copernican Principle (which says the Earth and sun are not unique) should have observational consequences and thus be testable. Galileo Galilei thought he could measure the true angular diameters of stars with his telescope; according…

General relativistic effects in astrophyiscal systems have been detected thanks to accurate astrometric measurements. We outline some keystones of astrometry such as stellar aberration (argument development during the years 1727-1872);…

We propose an experiment using a conventional optical telescope to determine whether aberration of starlight results from special relativistic effects external to a measurement sensor or from optical effects within a sensor. The proposed…

The effect of stellar aberration seems to be one of the simplest phenomena in astronomical observations. But there is a large literature about it betraying a problem of asymmetry between observer motion and source motion. This paper…

In 1919, Eddington and Dyson led two famous expeditions to measure the bending of light during a total solar eclipse. The results of this effort led to the first experimental confirmation of Einstein's General Relativity and contributed to…

Astrometric detection of an unseen companion is based on analysis of apparent motion of its host star around the system's barycentre. Systems with orbital period close to one year may escape detection if orbital motion of their host stars…

We present the first detection of parallax effects in a gravitational microlensing event. Parallax in a gravitational microlensing event observed only from the Earth appears as a distortion of the lightcurve due to the motion of the Earth…

Astronomers occasionally detect an object having unexpected shape, unexplainable photometry, or unprecedented spectra that are inconsistent with our contemporary knowledge of the universe. Upon careful assessment, many of these anomalies…

Great opportunities arise for teaching physics, astronomy, and their histories when new discoveries are made that involve concepts accessible to students at every level. Such an opportunity currently exists thanks to the fact that notes…

Observing artificial satellites is a relatively new and unique branch of astronomy that is very interesting and dynamic. One specific aspect of observing these objects is that although they appear amongst the celestial background, as…

Over the past century a succession of five different independent astronomical phenomena have been discovered, each appearing to be the result of a common underlying cause that also produces an unaccounted-for acceleration that is: quite…

The fields of occultation and microlensing are linked historically. Early this century, occultation of the Sun by the Moon allowed the apparent positions of background stars projected near the limb of the Sun to be measured and compared…

With several detections, the technique of gravitational microlensing has proven useful for studying planets that orbit stars at Galactic distances, and it can even be applied to detect planets in neighbouring galaxies. So far, planet…

We present a physical-optics based theory of the physical mechanism for aberration of starlight. We apply non-relativistic and relativistic theories for wavefront image formation and include the effects of optically transmitting media…

Since their discovery in 1973, Gamma-Ray Bursts (GRBs) have remained for many years one of the most elusive mysteries in High Energy-Astrophysics. The main problem regarding the nature of GRBs has usually been the lack of knowledge of their…

The phenomenon of counterrotation is observed when two galaxy components have their angular momenta projected antiparallel onto the sky. It follows that if the two components rotate around the same axis, the counterrotation is intrinsic. On…