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.
1 High mass stars may only stay on the main sequence for a few million years. 2  Eventually a star will run out of its hydrogen fuel, and begin fusing helium and other elements instead. 3  At that point it will leave the main sequence phase.4  Red dwarf stars will use up all their hydrogen and collapse directly into white dwarfs.he life cycle of a star can follow a few different paths depending on the mass it starts out with. Really massive stars may live for only a few million years before going supernova, while low mass stars such as the Sun may take billions of years to use up their fuel and then die relatively quietly.