PHYS133 – Lab 8 Deep Sky Objects from the Messier Catalog Goals: • Observe various deep sky objects and learn their size and nature What You Turn In: • Worksheet • Screencaps or sketches of the objects Background: Messier Objects: The nineteenth-century astronomer Charles Messier compiled a catalog of more than 100 objects that, unlike stars, showed an extended angular appearance on the sky. These became known as “Messier objects”, listed as M#. For this lab, we are going to investigate 7 deep sky objects of different types. Procedure Deep-Sky Objects from the Messier Catalog Use the Stellarium website (https://stellarium-web.org/) to explore these 7 Messier objects: M1, M13, M31, M42, M45, M49, M57 For each object do the following: 1. Use the search bar to find it and then zoom in on it 2. Take a screen snapshot or sketch the object. 3. Identify any common name for the objects (e.g. M1 = “Crab nebula”) 4. Use the azimuthal grid to estimate the size of the object. 5. Use the Wikipedia link to find the distance of the object in light years (ly). 6. Compute its physical size (in ly) from Size = (Angle Size/57 deg) x Distance. 7. Note which objects have the largest/smallest: angular size; physical size; and distance 8. Identify which of the follow types best describe each object: 1. Supernova remnant 2. Planetary nebula 3. Star-forming region 4. Open Cluster 5. Globular Cluster 6. Spiral Galaxy 7. Elliptical Galaxy UDel Physics 1 of 4 Spring 2020 Names: _________________ Section: ______________ _________________ Date: ________________ Data Sheet Deep Object Data M#/ Angular size Object type Distance (ly) Size (ly) Common name (degrees) UDel Physics 2 of 4 Fall 2020 Questions 1. Identify which objects have biggest/smallest: angular size; physical size; distance. 2. Next rank the physical size of each Messier object you calculated. Does this ordering make sense based on what you know of the objects? 3. How do each of these objects compare to the size of the Solar System (around 50 AU) and the size of the Milky Way (around 100,000 light years)? UDel Physics 3 of 4 Fall 2020 4. Identify which object best represents: The kind of galaxy we live in. A region where molecular clouds are contracting by gravity. The death of a high-mass star. The death of a low-mass star. A region with lots of young stars in our galaxy’s disk. A region with lots of old stars in our galaxy’s halo. A galaxy with mostly old stars. UDel Physics 4 of 4 Fall 2020 .