 Greetings and welcome to the Introduction to Astronomy. In this lecture, we are going to go through the graphing portion of the solar project to show you how to get the graph set up and to get that graphing started that will be required when you're writing up your final project which will be coming up soon. So let's go ahead and review some of the information about the project. First of all, just as a reminder, I gave you a set of data in a previous video I showed you how to do those calculations. You will need to include both of those data tables and the graphs that I'm showing you today will have to show both sets of data on the same graphs. So we'll be graphing the declination and the change in declination. You will set it up with my data and you'll add your data points to the same graphs for comparison. So you'll be submitting two data tables, one of your data, one of mine. You'll be submitting a declination graph that shows both sets of data and you'll be submitting a change in declination graph that shows both sets of data. Now as I told you before, you can email me the calculations when you're done if you wished me to review them. The same goes for the graphs. If you wish to email me the graphs, you're welcome to do so. I will be happy to review them but again, please allow 24 hours. So again, if you're doing this right before they're due, you're not going to have time to get feedback before they're due. I cannot guarantee. I can get them back to you in a very short time on Sunday afternoon or evening. And again, you must use the data I provide for the lab, Lab 8, in order to complete the solar project. If you don't use my data, you're not going to be able to get full credit. So even if you're not taking advantage of this to get some feedback on the calculations and graphs, make sure you do this lab and submit it because you are going to need this when you complete the final project. So let's go ahead and remind ourselves where we were. We were looking at the data table and we had completed a data table, something like this. I had done the calculations for the first two parts here and we had gone ahead and we're going to go ahead and graph those. Now what we're graphing is the date here is going to be the x-axis and we're going to graph the one graph will be the declination and the second graph will be the change in declination. So in one graph, we're going to calculate declination versus the date. In the second graph, we will do the change in declination versus the date. So the date will always be on the x-axis and on one side we'll be plotting declination and one will be plotting the change in declination. So let's look at how to set up the declination graph first and the declination graph here, using the graph paper I provide, you will set the date scale here. You will put the first date in the data table at week zero. Make sure you're not skipping in. Start at week zero and that allows you to fit all of the data on the graph. So in this case for fall you will go from August 24th to December 7th. Now that way this entire graph is set up and scaled properly so that you can use it for all data sets because you will not have made any earlier observations and you will be submitting the project before the last observations are due here. Now on the y-axis we're setting up the declination in degrees. Now the way the graph paper is set up, the easiest way to do this is to start off with negative 25 right at the bottom corner here and then work your way up by 5. So negative 25, negative 20, 15, and so on. Note that the graph paper is set up specifically for this by the week so that if you count each individual line here, the main line on the axis here is the 24th, the next one will be August 25th, 26th, 27th, 28th, 29th, 30th, and the next major division will be a week later on the 31st. So the graph paper is specifically set up for this project. Now once you do this we're going to plot the data points and we can put our two data points that we had in here and you're going to want to continue that but you'll see you'll plot those points. The first one here at 11 degrees and the second one at about 8.5 degrees. So we'll see that for the fall semester you will note that the declination does decline and you will see something roughly like this once you finish plotting all of your points. So you should see a decline. Now if you're taking it in the spring, you'll see an increase. You'll start off with negative declinations and you'll end up with positive. You're going to see the opposite of this graph if you're taking the class in the spring. So that's what you would be graphing and then you would be adding in your data points wherever they happen to fall in between mine. So let's plot some of those here. For example, if you made an observation on September 30th. This is the 28th, so two in would be the 30th. And suppose your declination point was a little bit higher up here. So you'd plot your point there. And you might have made another one on November the 1st which is over here and maybe it came out a little bit lower. So you will plot your points here. Now with mine you can draw a smooth line through the points. For yours just plot the data points. If anything falls completely off the scale, just make a notation that you made an observation here and it did not fit and it's way off the scale here or that it's way off the scale up above. This will not be as common with the declination graph but will happen on the other graph and that's perfectly fine. Just make a notation of those and that's fine. You don't want to change the scale because you won't be able to see the trends as easily. So that's the declination graph. Let's go ahead and look at the change in declination graph and you'll note that the date scale is exactly the same as it was for the previous one. So we're going to have the same date scale here as we had. The change in declination is in degrees per day and it starts at negative 0.5 down at the axis at the bottom. And then goes up by a tenth for each major division and will end at plus 0.5 up at the top. So that will set up the scales of the graphs then once we graph everything, we can start plotting it. Now in this case we only have one point and you see that one point down there for the 31st. Make sure you still leave the 24th here. You just will not have a point to plot there. And be very careful, do not plot it as a zero. A zero is a quite different thing than not having a value at all. So zero is a specific value for change in declination and there is no value exists for the 24th because you don't have anything to compare it to. And you can do the same thing with my data and draw a smooth line roughly through those points. And you should see a decline slightly at the beginning and then begin to increase and become less and less negative as you come toward the end of the semester. So you will see a graph something like this and again you're gonna do the same kind of thing with your points in mind. So if you have your points you may have made an observation here. And maybe your points you're gonna find a little bit more scatter on these. They're not gonna match my data as well and that's perfectly fine. Just plot yours where they fall and make note of any that are completely off the scale and where they are. Because again, you don't wanna rescale this. You wanna be able to see that trend as to where how the change in declination is occurring. So don't rescale it. If you get a point at negative two, you don't wanna readjust this for negative two. That'll make it, you'll crunch this up so much that you won't be able to see the trends easily. So that is how you set up these graphs. Let's go ahead and summarize a little bit with what we'll be doing. Again, I do recommend completing these early and submitting them to me by email. That way I can give you comments, get you make corrections before you're submitting the final lab. And this will minimize any deductions for the final project which you will be submitting these graphs with as well. So that concludes this lecture on the graphs for the Solar Observations Project. We'll be back again next time for another topic in astronomy. So until then, have a great day everyone and I will see you in class.