3-1 Discussion
This modules webtext focused on researching your issue in the natural sciences and evaluating different sources. In your initial post, explain what the biggest challenge you faced was when trying to find sources? What challenges did you encounter in trying to analyze a scientific source? How did you overcome them? Use specific examples in your post.
In response to your peers, describe how the challenges they faced compared to your own. What similarities and differences did you find? Share your tips for dealing with any issues you faced.
To complete this assignment, review the Discussion Rubric document
RUNNING HEAD: ASTROMETRY 1
ASTROMETRY 2
Astrometry
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Astrometry is the science of measuring the precise position of stars and monitoring their movements such as periodic shifts and any wobble at the stars’ positions. The specialists for the measurement of stars are referred to as astronomers, and they use a variety of techniques to track different earth objects. To find planetary items or to measure the distances of the stars, astronomers usually use telescopes or large area cameras, which are used to take clear pictures at various determined intervals (Penoyre, et al, 2020).
Then they study these images and detect solar system objects using their movements around the background of the stars because they are stagnant. Suppose any activity is observed per unit time. In that case, the astronomers look at the parallax, which could be caused by the earth movement during this time and consequently, the heliocentric distance to this object is calculated (Deller, et al, 2019). With the photographs’ help taken over a set period, and the calculations are done on the object, any unusual movement is obtained.
Astrometry is the earliest method that was used for the search of extrasolar planets. It is a very effective method because it can be applied to many stars, unlike photometry. Astrometric is significant because its measurements are used in the constrain of specific models in celestial mechanics. Besides, this technique is useful in other areas, such as galactic astronomy and stellar dynamics. It is also essential in the cosmic distance ladder because it is used to establish the parallax distance for the stars found in a milky way.
References
Deller, A. T., Goss, W. M., Brisken, W. F., Chatterjee, S., Cordes, J. M., Janssen, G. H., … & Lyne, A. (2019). Microarcsecond VLBI pulsar astrometry with PSR II. Parallax distances for 57 pulsars. The Astrophysical Journal, 875(2), 100. Retrieved from https://iopscience.iop.org/article/10.3847/1538-4357/ab11c7/meta
Penoyre, Z., Belokurov, V., Wyn Evans, N., Everall, A., & Koposov, S. E. (2020). Binary deviations from single object astrometry. Monthly Notices of the Royal Astronomical Society, 495(1), 321-337. Retrieved from https://academic.oup.com/mnras/article- abstract/495/1/321/5828731 Running Head: RESEARCH QUESTION 2
RESEARCH QUESTION 2
Research Question
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Research Question
Question
Why do Astronomers believe that the world is continuously expanding? How did they come to this conclusion?
Explanation
When scientist talk of expanding Universe, they mean that since the beginning of the Universe with the Big Bang, it has been growing ever since. In other words, galaxies found outside the world tend to move away from us, while the galaxies farthest away are moving the fastest. Based on the scientist’s reasoning, then regardless of the galaxy that one might be in, the rest of the galaxies are moving away from you. According to Conlon et al. (2017), galaxies move in space and not through space. The Universe lacks a centre, and everything tends to move away from everything else found in the Universe. The first idea about the expanding Universe was formulated by Edwin Hubble in 1925.in his work, “He proved that there is a direct relationship between the speeds of distant galaxies and their distances from Earth.” The concept was later named the Hubble’s Law. Hubble telescope used in making observations was also named after him. Hubble constant which is the “the single number that describes the rate of the cosmic expansion, relating the apparent recession velocities of external galaxies to their distance” (“What does it mean when they say the universe is expanding?”, 2020) was equally named after him.
References
Conlon, M., Coble, K., Bailey, J. M., & Cominsky, L. R. (2017). Investigating undergraduate students’ ideas about the fate of the Universe.Physical Review Physics Education Research,13(2), 020128. Retrieved from https://journals.aps.org/prper/abstract/10.1103/PhysRevPhysEducRes.13.020128
How do astronomers know the Universe is expanding?. (2020). Retrieved 8 September 2020, from https://www.science.org.au/curious/space-time/how-do-astronomers-know-universe-expanding
What does it mean when they say the Universe is expanding?. (2020). Retrieved 8 September 2020, from https://www.loc.gov/everyday-mysteries/item/what-does-it-mean-when-they-say-the-universe-is-expanding/