3 papers
astro-ph.SR2026
Refined reduction and standardisation of 53 years of UBV photometry at Hvar
Hrvoje BožiÄ, Hrvoje Božić, BožiÄ Hrvoje +48
Emission-line stars classified as Be exhibit light and colour variability on various timescales, ranging from days to decades. Their evolution must be constrained by long-term obse…
astro-ph.SR2025
BoÅ¡koviÄ's Spherical Trigonometric Solution for Determining the Axis and Rate of Solar Rotation by Observing Sunspots in 1777
Mirko Husak, Roman BrajÅ¡a, Dragan Å poljariÄ +5
In September 1777 RuÄer BoÅ¡koviÄ observed and measured the sun-spot positions to determine the solar rotation elements. In 1785, among other methods, he described a trigonometri…
astro-ph.SR2025
BoÅ¡koviÄ's method for determining the axis and rate of solar rotation by observing sunspots in 1777
Mirko Husak, Roman BrajÅ¡a, Dragan Å poljariÄ +5
In 1777 RuÄer BoÅ¡koviÄ observed sunspots, determined their positions and the solar rotation elements by his own methods briefly described here. We repeat his calculations of the…