Hello Chaunon,
using vector graphic you are free to draw any shapes even if they change at the runtime dynamically. However, the problem you will have, is the blur/glow effect. Drawing such effects dynamically at the runtime is not supported. Therefore, the unique way to get such effect is to prepare a set of images with different sizes for the tail:
Step 1: You will need to use a graphic editor (GIMP, Photoshop, Affinity Designer, etc.) to create the corresponding image assets.
Step 2: Add the images to Embedded Wizard as so-called bitmap resources.
Step 3: Depending on the actual size of the comet tail, select the right bitmap resource and display it in an Image view. For a short tail select the small bitmap, for large one the large version of the image asset.
For optimization purpose, I would recommend to configure the bitmap resources in the ALPHA8 format. Then you can modify the color of the glow/blur effect dynamically at the runtime and the bitmap resources will occupy less memory.
I hope, it helps you further.
Best regards
Paul Banach
