1.) Create a new document 300x100 with a black background.
2.) Go to Filter > Render > Lens Flare. Place the lens flare in the exact center (this is necessary). Besides that use default settings.
3.) Go to Image > Adjustments > Desaturate. Now the lens flare should be gray.
4.) Go to Filter > Artistic > Neon Glow. Change the color to white and use these settings:
Glow Size: -12
Glow Brightness: 15
you are done now if you want you can colorize the picture by hitting Ctrl + U, but I just left mine black and white. This is what i got: