False-colour composite image of nova T Pyxidis.The nova is surrounded by shells of gas thrown off during its explosion. The bright spots are caused by the gas interacting with interstellar matter or by the collision of fast-moving and slow-moving gas from several eruptions. This image is based on pictures taken by the Hubble Space Telescope.
nova
Plural:
Novas, orNovae
Related Topics:
star
light echo
explosive variable star

nova, any of a class of exploding stars whose luminosity temporarily increases from several thousand to as much as 100,000 times its normal level. A nova reaches maximum luminosity within hours after its outburst and may shine intensely for several days or occasionally for a few weeks, after which it slowly returns to its former level of luminosity. Stars that become novas are nearly always too faint before eruption to be seen with the unaided eye. Their sudden increase in luminosity, however, is sometimes great enough to make them readily visible in the nighttime sky. To observers, such objects may ...(100 of 331 words)