Related papers: Astronomical and Historical Evaluation of Molnar's…
Based on the planet-satellite dynamics, a new perspective on the birth and evolution of the Solar System was proposed in 2004. This new perspective has 1:2 Mean Motion Resonance (1:2 MMR, that is Ps/Pj = 2) implicit in itself . This paper…
From the time the first stars formed over 13 billion years ago to the present, star formation has had an unexpectedly dynamic history. At first, the star formation rate density increased dramatically, reaching a peak 10 billion years ago…
Stellar multiplicity is among the oldest and richest problems in astrophysics. Binary stars are a cornerstone of stellar mass and radius measurements that underpin modern stellar evolutionary models. Binaries are the progenitors of many of…
Palla & Stahler have recently argued that star formation in Taurus and other nearby molecular clouds extends over a period of at least 10 Myr, implying quasi-static cloud evolution and star formation. Their conclusions contradict other…
An ancient Egyptian Calendar of Lucky and Unlucky Days, the Cairo Calendar (CC), assigns luck with the period of 2.850 days. Previous astronomical, astrophysical and statistical analyses of CC support the idea that this was the period of…
The solar eclipse of Good Friday has always been recognized as a problem from the astronomical point of view. The date of Crucifixion has been investigated by many scholars and the most accredited one is friday 3 april 33, when, at sunset…
An impressive bulk of multiple astronomical observations indicates that there are plenty of objects in the universe with the age which cannot be explained by the conventional theory. A model is considered which successfully describes all…
We investigate possible reasons for the absence of historical records of the supernova of 1054 in Europe. At the same time, we search for the new evidences as well. We establish that the previously acclaimed 'Arabic' records from ibn Butlan…
The cross-identification of sources in separate catalogs is one of the most basic tasks in observational astronomy. It is, however, surprisingly difficult and generally ill-defined. Recently Budav\'ari & Szalay (2008) formulated the problem…
Every society has a story rooted in its most ancient traditions, of how the earth and sky originated. Most of these stories attribute the origin of all things to a Creator - whether God, Element or Idea. We first recall that in the Western…
The aging and gradual brightening of the Sun will challenge Earth's habitability in the next few billion years. If life exists elsewhere in the Universe, the aging of its host star similarly poses an existential threat. One solution, which…
With no firm evidence for life beyond our solar system, inferences about the population observers such as ourselves rests upon the Earth as a single input, at least for now. Whilst the narrative of our home as a 'humdrum' system has become…
There are about 6000 stars, that can be seen with the naked eye and have been observed for centuries for various purposes. More modern investigations using advanced telescopes show that our Milky Way, a quite common galaxy, consists of…
Since the dawn of telescopic astronomy astronomers have observed and measured the "spurious" telescopic disks of stars, generally reporting that brighter stars have larger disks than fainter stars. Early observers such as Galileo Galilei…
The last two years have seen widespread acceptance of the idea that the Milky Way halo was largely created in an early (8-10 Gyr ago) and massive ($> 10^{10} M_\odot$) merger. The roots of this idea pre-date the Gaia mission, but the…
In the past six years, Betelgeuse has been in the news and drawn significant public interest. Starting in October 2019, Betelgeuse underwent a striking dimming event, fading from magnitude 0.5 to 1.7 by mid February 2020 a threefold…
In 1717 Halley compared contemporaneous measurements of the latitudes of four stars with earlier measurements by ancient Greek astronomers and by Brahe, and from the differences concluded that these four stars showed proper motion. An…
Estimating ages for stars is difficult at best, but Galactic problems have their own requirements that go beyond those for other areas of astrophysics. As in other areas, asteroseismology is helping, and in this review I discuss some of the…
By c. 3000 BC, in the late Neolithic, there had been a significant change in the way people materialized their cosmology across Scotland with the introduction of free-standing stones. These were erected almost until the end of the Bronze…
Early attempts to apply asteroseismology to study the Galaxy have already shown unexpected discrepancies for the mass distribution of stars between the Galactic models and the data; a result that is still unexplained. Here, we revisit the…