Supermassive black holes (SMBHs) represent an important aspect of galaxy evolution theory that remains at the frontier of modern research. Like their stellar-mass versions, SMBHs…
The stellar photosphere, the “surface of a star,” is defined as the layer of its atmosphere at an optical depth τλ = 2/3 for a…
Among the pioneers of the idea of swirling vortices of gas being responsible for the formation of the solar system was Descartes (1644). In his…
Geomorphological, mineralogical and other evidence of the conditions favoring the existence of water on Mars in liquid phase is reviewed. This includes signatures of past…
The subject of the nature and origins of ultra-luminous X-ray sources (ULXs) remains at the frontier of modern research. Existing data allows to fit a…
It is suggested that two distinct Population III classes may have existed: population III.1 and population III.2. The former, consisting of stars of ∼ 100M⊙,…
I would like to discuss Jupiter’s energy balance, in particular the excess heat radiated by it to space and the amount of Kevin–Helmholtz contraction required…
The aims of this project are as following: Reduce multi-band (BVR) CCD data of the M 51, M 63, M 106 (NGC 4258) and NGC…
Following (Zwicky 1937) we start with the virial theorem that relates the average kinetic energy ⟨K⟩ to the average gravitational potential energy ⟨U⟩ of bodies in…
It is known that star formation occurs in regions where dense molecular clouds undergo gravitational collapse. While observations of cold dusty disks and envelopes require…