Nebulae: Stars that brighten and dim periodicallyÂ
Pulsars: Neutron stars that are formed when massive stars run out of fuel and collapseÂ
How many of the above pairs are correctly matched?
Only one
Only two
All three
None
Correct Answer: Option (d)
Cepheids, also called Cepheid Variables, are stars that brighten and dim periodically. Hence, pair 1 is not correctly matched.Â
A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form. Hence, pair 2 is not correctly matched.Â
Pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds. Hence, pair 3 is not correctly matched.Â