4 papers
Eta Carinae's historical light curve: evidence for cyclic Roche lobe overflow from the primary star
Augusto Damineli, Leonardo A. Almeida, Francisco J. Jablonski +5
The large amount of ground-based photometric measurements of Carinae obtained since 1940 have remained problematic for quantitative modeling due to the blending of flux from th…
Starspot temperature of CoRoT-2 from multiwavelength observations with SPARC4
Adriana Valio, Eder Martioli, Andre O. Kovacs +5
Measuring starspot temperatures is crucial for understanding stellar magnetic activity, as it affects stellar brightness variations, influences exoplanet transit measurements, and…
No evidence of intrinsic linear polarization in Nova Vel 2025 (V572 Vel)
Isabel J. Lima, Marina M. C. Mello, Claudia V. Rodrigues +3
We report on polarimetric observations of V572 Vel (Nova Vel 2025) conducted on June 26th and July 21st, 2025, shortly after its nova eruption was discovered. Our measurements in t…
SPARC4 control system
Denis Bernardes, Orlando Verducci Junior, Francisco Rodrigues +15
SPARC4 is a new astronomical instrument developed entirely by Brazilian institutions, currently installed on the 1.6-m Perkin-Elmer telescope of the Pico dos Dias Observatory. It a…