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.
A star does not stay the same color throughout its lifecycle, since the surface temperature alters depending on the type of fusion reaction fuelling the star at the time. Depending on the initial mass of the star, it will evolve along the lines of one of three main star types: low-mass stars, intermediate-mass stars (like our sun) and high-mass stars.