In the article, “Star in closest orbit ever seen around black hole,” the author explains how a team of astronomers using land based telescopes to find evidence that a star fly’s around a black hole very tightly. Exactly “twice an hour” according to Phys.org. The article says “This could be the tightest orbital dance ever seen by a black hole and a companion star in our own Milky Way galaxy”. Also in the article the author talks about how the discovery was made. “This discovery was made using two of NASA’s space-based telescopes, the Chandra X-ray Observatory and NuSTAR, and the Australia Telescope Compact Array”. Which shows it took a lot of technology to make this discovery. Than the author talks about the separation between a dwarf star and a black hole and how because the dwarf star is so close to the black hole material from the star is being ripped away. Lastly as i recall from the article the author talks about new observations from a new system called the X9 . the unique thing with this system is the x ray brightness changes consistently every 28 minutes and from that astronomers were able to determine that a dwarf star orbited a black hole in that amount of time.
Objective number seven was to be able to explain how astronomers use light to determine the chemical composition, the speed and direction of astronomical objects motion. Astronomers were able to obtain knowledge of a star by using X-ray light. During class , through the power point slides we learned that there are different forms of light such as infrared, ultraviolet, and X-rays. We also learned light is a wave, which is something that can transmit energy without carrying material along with it. Different forms of light have different wavelengths, some shorter and some longer. Light can be used to learn about the motion of distant objects from changes in their spectra caused by the Doppler effect. The Doppler effect tells us how fast an object is moving toward or away from us. Spectral lines are shifted to shorter wavelengths (a blueshift) for objects moving toward us and to longer wavelengths (a redshift) for objects moving away from us. All of this applies to this article because astronomers were able to use the shifts in X-ray brightness of the star to estimate how fast it is orbiting the black hole. As its light moves toward us it would be considered blueshifted and as its light moves away from us it would be considered redshifted. The star’s light is what tells us about its motion.
Personally i really enjoyed this article because i found it very interesting how fast a star can orbit a black hole . I would of never guessed anywhere as fast as every 28 minutes. Also,I did not know that once a star got that close to a black hole that it was even possible for it to escape getting sucked up. I learned that there are so many different things that light can teach us about what is out there in space.