I read an article entitled, “Astronomers discover a white dwarf that acts like a pulsar,” on astronomy.com, that I believe coincides with our twelfth conceptual objective, “I can explain how astronomers use the Hertzsprung-Russell diagram to study properties of stars.” This article, by Alison Klesman, states “a pulsar is a type of neutron star that emits focused beams of radiation from its poles as it spins.” Astronomers have discovered a pulsar that is not a neutron star at all; instead, it is a white dwarf! It is the first white dwarf pulsar to ever be discovered. Professors Tom Marsh and Boris Gänsicke at the University of Warwick’s Astrophysics Group, and Dr. David Buckley of the South African Astronomical Observatory discovered it! They found that AR Scorpio, a binary system that sits in the constellation Scorpius, contains a white dwarf pulsar. AR Scorpio system contains a white dwarf and a red dwarf that orbit each other every 3.6 hours with a distance of 1.4 million kilometers between them. Every two minutes the white dwarf rotates around its axis and blasts the red dwarf with a beam of radiation. The white dwarf pulsar in AR Scorpio is 200,000 times as massive as Earth, and has an electromagnetic field that is 100 million times the strength of Earth’s. This is why the white dwarf emits beams of radiation as a pulsar.
I am able to connect this article to our conceptual objective because of what I have learned during the previous class period. As I learned in the class discussion and from the power point slides, white dwarfs are hot stars that are dim and have a very small radius; they are not on the main sequence line of the H-R diagram. Therefore, the white dwarf, as discussed in the article above, would reside in left-hand side of the diagram, probably in the lower left corner. We did a lecture tutorial titled “H-R Diagram,” in which I learned how to read a H-R diagram, and where certain stars belong on the diagram. Because of this tutorial, I know where the white dwarf would be placed on the diagram.
All in all, I thought this article was really interesting! I did not know what a pulsar was until I read this article and did a little research. After reading about pulsars, I think the discovery in this article is amazing! A white dwarf pulsar?! That seems really cool to me. I was excited to find such an interesting article that referenced a white dwarf and was ecstatic to connect this to the H-R Diagram with my new-found knowledge on this topic. This conceptual objective was definitely one of the easier (and more fun) topics!