6 papers
The Reflecting Heliometer of Rio de Janeiro after 6 Years of Activity
Sergio C. Boscardin, Costantino Sigismondi, Jucira L. Penna +3
Started its regular, daily operational phase in 2011 and installed in 2009 by the occasion of the Symp264 in the XXVII IAU GA at Rio de Janeiro, the results so far obtained show th…
The solar diameter series of the CCD Solar Astrolabe of the Observatório Nacional in Rio de Janeiro measured during cycle 23
Costantino Sigismondi, Sergio Calderari Boscardin, Alexandre Humberto Andrei +3
The interest on the solar diameter variations has been primary since the scientific revolution for different reasons: first the elliptical orbits found by Kepler in 1609 was confir…
Solar astrometry with Rio Astrolabe and Heliometer
Costantino Sigismondi, Sergio Calderari Boscardin, Alexandre Humberto Andrei +3
Monitoring the micro-variations of the solar diameter helps to better understand local and secular trends of solar activity and Earth climate. The instant measurements with the Ref…
Development and first year of results from the heliometer of Observatorio Nacional
Alexandre H. Andrei, Victor A. D'Avila, Eugenio Reis Neto +5
Recent research on global climate changes points to three distinct sources of climate disturbance: anthropogenic; natural changes in the oceans and atmosphere; and irregularities i…
A new approach for the heliometric optics
Victor d'Avila, Eugenio Reis Neto, Alissandro Coletti +6
The heliometer of Fraunhofer in Koenigsberg (1824) is a refractor in which the lens is split into two halves to which is applied a linear displacement along the cut. Later in 1890s…
Parallaxes of Southern Extremely Cool objects - I: Targets, Proper motions and first results
Alexandre H. Andrei, Richard L. Smart, Jucira L. Penna +11
We present results from the PARallaxes of Southern Extremely Cool objects (PARSEC) program, an observational program begun in April 2007 to determine parallaxes for 122 L and 28 T…