from
The Collaborative International Dictionary of English v.0.48
Nova \No"va\ (n[=o]"v[.a]), n.; pl. L. {Novae} (n[=o]"v[=e]), E.
{Novas} (n[=o]"v[.a]z). [L., fem. sing. of novus new.]
(Astron.)
A star which suddenly increases in brightness thousands of
times, then fades back to near its original intensity. It may
appear as a "new" star if its original brightness was too low
for routine observation. A star which suddenly increases in
brightness to many millions of times its original intensity
is a {supernova}, and the postulated mechanisms for the
increases of brightness of novae and supernovae are
different.
Note: The most important modern novae are:
{No"va Co*ro"nae Bo`re*a"lis}[1866];
{No"va Cyg"ni}[1876];
{No"va An*dro"me*dae}[1885];
{No"va Au*ri"gae}[1891-92];
{No"va Per"se*i}[1901]. There are two novae called {Nova
Persei}. They are:
(a) A small nova which appeared in 1881.
(b) An extraordinary nova which appeared in Perseus in 1901.
It was first sighted on February 22, and for one night
(February 23) was the brightest star in the sky. By July
it had almost disappeared, after which faint surrounding
nebulous masses were discovered, apparently moving
radially outward from the star at incredible velocity.
[Webster 1913 Suppl. +PJC]