In astronomy, photometry has always been an important technique for determining the magnitude of a celestial object and thus gathering more information about it. Obtaining relevant information about stars by aperture photometry is a very important step in astronomical research. In this way, we analyzed five stars observed by DECam to obtain their magnitude, effective temperature, spectral type, and distance in this experiment. Through calculations, we derived reasonable results, and we successfully analyzed the image of these five stars and obtained useful and important information for them. We found that the spectral type for Star 1 is F, for Star 2 is K or M, for Star 3 is G or K, for Star 4 is M, and for Star 5 is F. The absolute magnitude may vary depending on which stellar type they are.
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As the perseverance of our solar system, the Sun is also the closest star to us. The importance of studying the characteristics of the Sun is self-evident. We set up experiments to analyze the spectrum of the visible wavelengths of the Sun. Through the analysis of eight sets of high-resolution spectra, we identified 17 Fraunhofer lines, corresponding to 9 different chemical elements. The 17 Fraunhofer lines are K, H, h, G, G', e, d, F, c, b4, b1, b2, E2, D2, D1, C, and B lines. The 9 different chemical elements we identified are Ca+, Hδ, Fe, Hβ, Mg, Na, Hα, and O₂.
Since its discovery, the 21cm hydrogen line has played a crucial role in astronomical research, both in radio astronomy and cosmology. By observing the 21cm hydrogen line and analyzing its properties, we can better detect objects in the universe and study the early universe. Hydrogen is abundant in the universe, and the column density of hydrogen atoms provides valuable information. For example, we can use it to study the interstellar medium, the epoch of reionization, and the transition from a neutral universe to one that is fully ionized. In this paper, we observed the 21cm hydrogen line in a selected region and calculated the hydrogen column density of this region as (2.32 ± 0.06) * 10²⁰ cm⁻², with a velocity dispersion of 22.40 ± 0.67 km/s.
This review examines whether deuteration fractionation can serve as a probe of the chemical state in massive star formation regions. Previous theory has predicted that the column density ratio of a molecule containing D to its counterpart containing H can be used as an evolutionary tracer in the low-mass star formation process; this was also confirmed by observation. However, such theories in high-mass star-forming regions are still poorly argued.
In this paper, we give an introduction to this theory and also introduce the different stages of star formation respectively. By analyzing the data and conclusions of different studies, we can confirm that deuteration fractionation can be used as a probe for the stage of massive star formation. Finally, we discuss the trend of deuterium fractions with different physical parameters of different star formation stages. Studies on the relationship between deuteration fractionation and physical parameters may yield more useful information about star formation and evolution in the future.