The Photometry Tool in Maxim measures the brightness of a selected object in an image. You can use the Photometry Tool to measure changing brightness in an object, such as a variable star or a eclipse, or a small or rotating body like a planet or asteroid. By analyzing the light curve of an object, you can learn information about its physical properties. To produce a light curve with the Photometry Tool, first, go to the Analyze tab at the top of the window and select Photometry. When using the Photometry Tool, it is important that the images you are using are aligned. To produce a light curve, we will need to tag several objects in our set of images. Click on the drop down menu under Tagged Objects to display a list of tags. First, select your object. If the object appears stationary like a variable star or binary, select New Object. If the object moves across the set of images, like a planet or asteroid, select New Moving Object. Click on the object in the image. You will see that the selected object is now listed under the Tagged Objects list. In order for Maxim to analyze the change in brightness of the object, it needs a point of reference. Go to the list of tabs and select New Reference Star. Then select a star in the image. You will want to use a star with a known magnitude to produce a light curve which accurately plots the changing magnitude of your object. However, for this tutorial, we will simply use a magnitude of zero. If the reference object itself is variable, it will skew the resulting data. To ensure that this reference star is not variable, we will select two check stars as well. Go to the tag list and select New Check Star. Then select two to three stars in the image. Now that we have selected our objects, we will want to ensure that they are tracked throughout the series of images. Go to the image list and select the last image on the list. Find your object in the image and select it again. Maxim can now produce a light curve based on the apparent magnitude of your object. To view the light curve, click on the View Plot button at the bottom of the Photometry window. You can export your light curve as a comma-separated values file by clicking the Save button at the bottom of the window and selecting Save as CSV.