nebulosity

The hot central star can be seen faintly near the center of the nebulosity.

From Textbooks ● Oct. 13, 2016

Later, the stars wander out of their nursery to seek their fortunes in the Milky Way, stellar adolescents still surrounded by tuffs of glowing nebulosity, residues still gravitationally attached of their amniotic gas.

From "Cosmos" by Carl Sagan

A peculiar veiled or tinted appearance has been remarked in some cases visually, and examination of the photographs strongly confirms the existence of absorbing nebulosity.

From Astronomy: The Science of the Heavenly Bodies by David Peck Todd

The ‘glow’ which surrounds them has been observed in a few instances to have vanished without leaving any trace of nebulosity behind, but the causes which have brought about such a result are entirely unknown.

From The Astronomy of Milton's 'Paradise Lost' by Thomas Nathaniel Orchard

There was no connecting nebulosity between these objects, the tails of the two smaller not reaching each other, or the large comet.

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Agnes M. (Agnes Mary) Clerke

These have no tails, and are probably mere nebulosities, without solid nuclei.

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Agnes M. (Agnes Mary) Clerke

Whence came these sparkling nebulosities, these mists of light?

From The Metal Monster by Abraham Merritt

Existence, to follow out the argument, is not always painted in shadow, its horizon obscured by dark-tinted nebulosities!

From She and I, Volume 2 A Love Story. A Life History. by John C. (John Conroy) Hutcheson

Mere comets or vague nebulosities in the firmament, without a form, and without a home.

From Words of Cheer for the Tempted, the Toiling, and the Sorrowing by T. S. (Timothy Shay) Arthur

Through the battling nebulosities Yolara's face swam forth—horror-filled, distorted, inhuman!

From The Moon Pool by Abraham Merritt