Astronomy   View all facts   Glossary   Help

abstraction > mathematical concept > number > quantity > radiation measurement > spectral feature > spectral line > absorption line > Fraunhofer line > D line

D line
subject			fact

D line	has definition Spectral line of neutral sodium, also the strongest interstellar line.
	is a kind of interstellar line
	is a kind of Fraunhofer line
	is a kind of interstellar line
	has species Na I
interstellar line	has width narrow
	has detection procedure narrow absorption lines which don't participate in the periodic Doppler shift of intrinsic absorption lines in a binary star
	has equivalent width depends on the amount of absorbing matter between the source and the observer
	occurs in O stars
Fraunhofer line	has dicovery date 1814
	has discoverer Joseph Fraunhofer
	occurs in Sun
absorption line	has antonym emission line
spectral line	has transition
spectral feature	has wavelength
radiation measurement	has unit radiation unit
number	has value

Kinds of D line :

• D1 line (3 facts) - Spectral line of neutral sodium.
• D2 line (3 facts) - Spectral line of neutral sodium.

Next Fraunhofer line: E line    Up: Fraunhofer line, interstellar line    Previous Fraunhofer line: B band