The main researcher in the study is Prof. Mashhoor Ahmad Al Wardat, Professor of Astrophysics in the Department of Applied Physics and Astronomy at the University of Sharjah and Deputy General Director of SAASST for Academic Affairs and the Sharjah Astronomical Observatory.  The team also includes: astronomer assistant researcher Abdullah Hussein from Al-Bayt University in Jordan; His Excellency Prof. Hamid M.K. Al Naimiy, Chancellor of the University of Sharjah, and General Director of SAASST, and President of the Arab Union for Astronomy and Space Sciences; as well as Prof. Martin Barstow, Professor of Astrophysics and Space Science at the University of Leicester, one of the pioneers of astronomy and space sciences in Britain, former president of the Royal Astronomical Society, and a member of the team of Gaia Space Telescope.

This publication comes within SAASST’s endeavor to promote astronomy and space sciences research and projects, and to educate students and enthusiasts in this field. This to achieve its goals set by His Highness Sheikh Dr. Sultan bin Mohammad Al Qasimi, Member of the Supreme Council, Ruler of Sharjah, and President of the University of Sharjah. His Highness founded SAASST as a national development project and a scientific research headquarters that seeks to serve and educate society in all areas of space sciences. And to be a global leader in space science research and projects to solidify the UAE’s position as a scientific hub at the regional and global levels.

The research was published under the title “Comparison of Gaia and Hipparcos parallaxes of close visual binary stars and the impact on determinations of their masses” in one of the most prestigious scientific journals: Publications of the Astronomical Society of Australia issued by Cambridge University during the month of January (1/18/2021).

The idea of ​​the research began more than two years ago with the release of the second set of data of the European Space Agency’s Space Telescope “Gaia”, which was launched in 2013. It is one of the European Space Agency's missions for precisely measuring the positions, distances, and motions of stars. Prof. Mashhoor Ahmad Al-Wardat noted some discrepancies in the measured distances of binary stars between the observations of the Gaia Space Telescope, published in 2018, and the observations of the Hipparcos Space Telescope, published in 1997 and modified later in 2007. The researcher Abdullah Hussein then collected the required data which was analyzed by the team using the "Al-Wardat’s Method for Analyzing Close Visual Binary and Multiple Stars."

This study supports scientific research efforts and enhances the possibility of determining the distance of binary and multiple stars. The difficulty of this lies in the fact that these stars are composed of two or more stars revolving around each other, and they are so close to each other that they appear as one star even when observed with telescopes. But space telescopes and some large Earth-based telescopes can distinguish “resolve” these stars from one another. Although this helps to understand what these stellar systems are, it causes an imbalance in the accuracy of measuring their distances. This is because this process depends on observing the system in two periods separated by six months, which is the period of the Earth's rotation around the Sun. This way it becomes the base of the measurement triangle of the parallax, and that is long enough to change the center of brightness of the two stars in some cases. This in turn leads to an error in the measurement of the distance, and this error can be close to the value of the dimension itself.

This study from the Sharjah Academy for Astronomy, Space Sciences and Technology at the University of Sharjah found this contradiction in a group of stellar systems between observations of Hipparcos and those of the modern Gaia telescope. It proposed re-analyzing these stars in another way using "Al-Wardat’s Method for Analyzing Close Visual Binary and Multiple Stars." This method is considered one of the innovative methods in the complex analysis of such stars, and it is based on several equations and programs to obtain the physical and engineering properties of such systems. This in addition to the estimation of what is called the dynamical parallax of these stars, which is more accurate than the observations of these telescopes in the case of close visual binary stars. Thus, we reach an accurate measurement in determining the distance of these stars, which contributes to strengthening of scientific studies and research in the field of studying binary and multiple stellar systems. It also provides the knowledge, awareness, and infrastructure necessary to support various efforts in the space sector, in line with the strategic objectives of the United Arab Emirates. This while also enriching the educational process nationally, regionally, and internationally.

Research details can be viewed using the link: https://bit.ly/2NxX4x9