68 citations · 268 across the 12 of their papers we have counts for
12 papers
Parallaxes of southern extremely cool objects III: 118 L \& T dwarfs
R. L. Smart, B. Bucciarelli, H. R. A. Jones +17
We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multi-epoch photometry of L and early T dwarfs. The o…
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…
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…
Parallaxes of Southern Extremely Cool objects (PARSEC) II: Spectroscopic Follow-up and Parallaxes of 52 Targets
F. Marocco, A. H. Andrei, R. L. Smart +8
We present near-infrared spectroscopy for 52 ultracool dwarfs, including two newly discovered late-M dwarfs, one new late-M subdwarf candidate, three new L and four new T dwarfs. W…