3 citations · 6 across the 11 of their papers we have counts for
11 papers
42 Years of Continuous Observations of the Solar Diameter from 1974 to 2015
Alexandre H. Andrei, Sergio C. Boscardin, Jucira L. Penna +2
Several group in the World followed the solar diameter with dedicated instruments, namely solar astrolabes, since 1974. Their data have been gathered in several observing stations…
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…
Optical Deformations in Solar Glass Filters for High Precision Astrometry
Costantino Sigismondi, Alexandre Humberto Andrei, Sérgio Calderari Boscardin +2
Measuring the solar diameter at all position angles gives the complete figure of the Sun. Their asphericities have implications in classical physics and general relativity, and the…
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…
The Heliometer of Rio de Janeiro in Operation - 2010 to 2013
Alexandre Humberto Andrei, Costantino Sigismondi, Eugenio Reis-Neto +2
Out of the three quantities that characterize the state of an isolated gaseous body: pressure, temperature and volume the radius is the only one directly measurable for the Sun, wh…
A cycle of measurements of the solar semidiameter with the astrolabe of Rio de Janeiro (1998-2009)
Sérgio Calderari Boscardin
The solar astrolabe at Observatorio Nacional has been doing a series of solar semidiameter measurements, extending from 1998 up to 2009, to a total of 21640 observations of the Sun…
Diameter and solar figure observations in the solar activity context with the astrolabe of Rio de Janeiro in 1998-2003
Sérgio Calderari Boscardin
From 1998 to 2003 the CCD Solar Astrolabe of the Observatorio Nacional in Rio de Janeiro made more than 20000 observations of the Solar Semidiameter. In the present work similar co…
Analysis of a series of measurements of solar semidiameter variations during 2001 at the astrolabe of Rio de Janeiro
Sérgio Calderari Boscardin
From 1997 the Observatorio Nacional has been observing the Sun with an astrolabe in order to study variations on the solar semi-diameter. Till now more than 20.000 observations wer…
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…