Greetings and welcome to the Introduction to Astronomy. One of the things that I like to do in each of my introductory astronomy classes is to begin the class with the astronomy picture of the day. From the NASA website that is APOD.nasa.gov slash APOD. Today's picture for August 31st of 2020. Well it is titled SS433, binary star micro quasar. So what do we see here? Well this is a star first catalogued as SS433 and named after the catalog of the two astronomers Stevenson and Sendoulek who cataloged this back in the 1970s. And this was star number 433 in their catalog of stars that had unusual emission lines. So it was an unusual star to start out with and as we've studied it more and more we have found more about it and it's actually a very unusual object. And in fact we now know that it is a binary system with an ordinary star and a compact object, a neutron star or black hole. And what we're going to see here is a simulation of this and the orbit of these two objects. So when two objects orbit very close to each other, a mass can be transferred from one to the other and can therefore cause energy to be produced. And as we play the video what we'll see is matter being torn from one star and then spiraling into a disk around the compact object with some material beaming out in jets. Now because of the procession of the object those jets will come out in helix or spiral pattern and we can see that from several different locations here as we look around. Now this is also, this object is also at the center of a supernova remnant. So this star is likely one that was a supernova long ago and the compact remnant be left behind is still present there. So we call it a micro quasar because this is the same type of process that we believe goes on in a quasar except in a quasar it is a much larger scale. So within the quasar we would see a large amount of material going on to a supermassive black hole, something many millions of times the mass of our sun and then the same but the same process would occur. It would spiral into the accretion disk jets of material would come out and the tremendous amounts of energy would be produced. So it is a chance to look at something much closer than a quasar which are all many billions of light years away. But to study the same process and in fact at the end you see kind of a beacon up towards the top of the supernova which is actually a very strong gamma ray source. Now this is still something surprising to astronomers because it seems to be related to SS433 itself near the center. However it is actually quite a ways away but it does have a pulsation period that matches the procession period of the jet and this is something that astronomers do not yet understand exactly what if any the relationship is between these two. So studying SS433 is a chance to look at an example of the process that forms a quasar at a much closer distance than the quasars that we see that are really out at the edges of the universe. So that was our picture of the day. For August the 31st of 2020 it was titled SS433 binary star micro quasar. We'll be back again tomorrow for the next picture previewed to be salted asteroid. So we'll see what that is about tomorrow and until then have a great day everyone and I will see you in class.