Spectral types and Hγ (W Hγ) equivalent widths have been derived from low dispersion (92 Å/mm and 51 Å/mm) spectrograms of the brightest stars in NGC 281, NGC 1893 (Aur OB 2), NGC 6823 (Vul OB 1), NGC ...
What is the origin of the letters used in star classification? Why didn't astronomers use ABCD? J. HaldimanChicago, Illinois ...
The Sun's recent anomalous behavior, including an extended solar minimum and reduced sunspot activity, poses questions about its "normality" for a G2 spectral type star and challenges current ...