Self-certification. Employers can also ask employees to fill in a form when they return to work to confirm theyâve been off sick for up to 7 days. This is called âself-certificationâ. Employers usually provide their own version of this form.elf-certification. Employers can also ask employees to fill in a form when they return to work to confirm theyâve been off sick for up to 7 days. This is called âself-certificationâ. Employers usually provide their own version of this form.
Â· just now. 1  The most massive stars (OB stars) have the shortest life. K and M stars are the least massive and have the longest lives. 2  McGarnigle is the most correct here. Type O and B are the hottest, most massive stars and, by virtue of their extreme mass, are the shortest lived.
The life expectancy of a star (E) depends on its mass (M), roughly following the model of E = M-2.5. For a star with a mass twice that of our sun (enter 2 in place of `M`), th â¦ en the lifespan will give 0.177. Our suns lifespan is around 10 billion years, so this would equate to 1.77 billion years.