A stellar explosion, also known as a NOVA (4 letters), is an astronomical event in which a star suddenly increases its brightness by a factor of up to 20, 000 times. This is caused by a sudden release of energy from the star's surface, resulting in a brightening of the star that can last for several weeks or months. The term 'NOVA' comes from the Latin word for 'NEW, ' referring to the fact that the star appears to have been newly created.