Spectroscopy at Megnaritaville

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In late January 2009, Bob Stephens and Ralph Megna devoted several nights to collecting spectra of various subjects, including asteroids, nebula, stars and galaxies, using the 14-inch Meade LX200R PopeScope.

One of their targets was M42, the great nebula in Orion (see visible light image here). Spectra from their observations were processed and analyzed in VSPEC. The results included the data chart (bottom of graphic below), a synthesized color spectrum (immediately above chart) and a comparison spectrum obtained at a professional observatory (top).

This analysis shows why M42 looks slightly greenish when viewed through a moderately-sized scope in a dark sky - much of the light energy comes from the emissions of O-III and hydrogen-beta. The red light from hydrogen-alpha and sulfur is more difficult for the human eye to detect, but is obvious in time-exposure images.

Bob Stephens and Ralph Megna with the PopeScope and SBIG DSS-7 spectrascope with ST-7 camera in January 2009

More on Spectroscopy: Redshift Labs at MegnaritavilleRedshift.html