Prof. José Renan de Medeiros receives the UFRN Outstanding Researcher Award

Professor José Renan de Medeiros do Departamento de Física (DFTE) receives the UFRN Outstanding Researcher Award in the area of Science and Engineering. The award is promoted by the Pro-Rectory of Research at UFRN and aims to value the institution’s researchers and their contributions to the development of science. Professor José Renan de Medeiros is the leader of the UFRN Astronomy Group, being a researcher 1A of CNPq and a member of the Brazilian Academy of Sciences. He was a member of the CNPq Physics and Astronomy Advisory Committee (CA-FA), member of the CAPES Physics Committee, Head of DFTE and Coordinator of the Graduate Program in Physics (PPGF). Click here for additional information.

Doctoral Qualifying Exam

In October, numerous talks associated to Doctoral Qualifying Exam are going to happen.
Click on the links below and follow the program!

The Future of the Sun

A major obstacle to achieving a fully interpretation of stellar ages and global properties of solar analogs lies the difficulty of measuring distances from stars. This is even more complicated for stars observed by space telescopes such as CoRoT and KEPLER,  that have looked far distant objects in the research for faint stars and  planetary systems similar to our Solar System.

For solar analog stars, ages can be inferred through rotation,  and rotation can be measured through photometric observations performed with the space telescope such as KEPLER, however the lack of precise determination of the evolutionary status of these solar analogues and  solar twins observed by the such  satellites, CoRoT and KEPLER , was a unanswered question.

Using observational data obtained by the GAIA satellite, recently launched by the European Space Agency (ESA), and physical models for stars also observed by the KEPLER satellite and through analysis based on physical models for measurements along within  photometric time series, the scientists published an  impactful results on the properties of old stars similar to the Sun, and with consequences for the studies of the future of the Sun.

The international team of scientists led by Prof. José Dias do Nascimento Jr, from UFRN, currently at CfA-SAO Harvard, publish today in The Astrophysical Journal, a precise analysis  of evolutionary status and rotation for a unprecedent sample  of solar twins that rotate slowly than the Sun, and therefore older. The investigative research analyzed distances through the parallax measurements from GAIA satellite and photometry with the KEPLER satellite. More than 30,000 stars were observed with NASA’s Kepler and measurements of rotation periods and analysis of their distances was presented. Stars more massive or much smaller than the Sun were excluded from work.

“Our program’s started with 30,000 stars, and we investigated a sample of 193 solar analog stars, and we reported rotation periods for hundred of solar analogs. In this study we are also presenting for the first time, rotation period,  as  well a determination of evolutionary status.”

“From our sample, we are delivering 10 solar analogues slower than the Sun, and these objects represent the future of the Sun in terms of rotation period. These join results from our team and published in 2009. The already discovered stars CoRoT Sol 1, which was the first solar twin characterized photometrically by a space observatory and confirmed by spectroscopic observations with the 8.2-meter SUBARU telescope was the only one on this category.  The Subaru telescope is installed near the summit of Mauna Kea mountain in Hawaii, USA. In this current project, some of these solar analogs are in the observational programs  already started  this week  at the Mercator Telescope, in the Canary Islands (Photo above). This is a second stage of the project. The continuity of the research must reveal an important set of other characteristics of those objects”.

Link to paper: https://iopscience.iop.org/article/10.3847/1538-4357/ab9c16

Authors
UFRN Brazil Eduardo Nunes, Leandro Almeida, Jefferson Soares Matthieu Castro,
USP Brazil Jorge Melendez, Diego Lorenzo, Y. Galarza,
USA CfA-Harvard S. H. Saar, S. Meibom,
Germany Potsdam: S Barnes,
Austria P. G. Beck


Photos of the Mercator Telescope made on August 5 by Dr. Paul Beck, co-author of the study. Mercator it is a 1.2 m telescope located at the Observatorio del Roque de Los Muchachos in La Palma, Spain. It is operated by Katholieke Universiteit Leuven (Leuven University), Belgium, in collaboration with the University of Geneva Observatory and is named is in honors to famous cartographer Gerard Mercator. The telescope was completed in 2000 and is mostly used for exoplanet research programs. Some of the twins in this project are observed there.

SBF Award to Doctorate Thesis 2016/2017

PPGF has representants in the SBF Award to Doctorate Thesis 2016/2017. São eles:

  • Prof. Dr. Bruno Carvalho, with the Thesis intitled “Raman Spectroscopy in MoS2-type transition-metal dichalcogenides”; Advisor Prof. Marcos Pimenta (UFMG).
  • PostDoc Dr. Diego Paiva Pires, with the Thesis intitled “Geometria da informação quântica: uma abordagem geral acerca do tempo de evolução”; Adivisor Prof. Diogo O. Soares Pinto (IFSC – USP).

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