Sodium in all its states !
Recommended equipment : Lhires III, eShel
Time : 1h
Sodium element has a nice spectral signature with two narrow lines in the yellow. Those lines, D1 & D2, are at wavelength 589.00nm and 589.59nm, split by about 6 angstroems only.
You can get a hint of this doublet amission lines in street lamps as several of them, based on sidium, display a yellow color. The same color appears when you throw salt (which contains sodium) on a candel flamme. But you can also see the same doublet in numerous stars.
Following observation of D1/D2 sodium doublet have been done with a Lhires III spectrograph and a digital SLR. With its 2400 lines/mm grating, Lhires III resolution is spliting the doublet widely !
Spectrum of slat bruned on a candle
Electrified pickle spectrum (!)
Street lamp spectrum
Star spectrum (Betelgeuse)
Christian Buil web page on sodium and Benoit Minster pickle with 220V through it!
http://www.astrosurf.com/buil/io_sodium/obs.htm : Sodium emission lines Sodium from Io satellite