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The first 50 years of use of the 200-inch Hale telescope at Mount Palomar Observatory, 1949-1999, are reviewed with attention to the infrared and instruments, spectrophotometry and spectroscopy. The astronomers looked at the spectra of stars, AGNs, interstellar matter and quasars in detail. Spectral resolutions were from 1000 A for broadband photometry to 0.04 A using interferometry.

Teaching about the origin of the elements can be an effective way to introduce secondary school students of chemistry to the subject. Cosmology can serve as a logical introduction to chemistry and can be a basis for developing other basic topics. Astrochemistry extends across boundaries into physics and shows students that there in continuity in study of the natural world. A teaching unit for this area was developed in accordance with guidelines of the 1997 Frameworks curriculum document of the Commonwealth of Massachusetts and was intended to be a step toward breaking down boundaries between disciplines. In teaching cosmology many other topics can be taught including units, significant figures and orders of magnitude. Art, literature, and music referring to stars can be employed as well.

Episodes of thermonuclear burning deep within red giant stars generate large quantities of the element fluorine. A. Jorissen and colleagues devised a new method of spectral analysis and found that the red giants have 30 times as much fluorine as the Sun. The red giants' plenitude of fluorine may result from a reaction sequence in which a radioactive fluorine isotope, 18F, is yielded by the combination of 14N and an alpha-particle or helium nucleus.

Star HD52961, which belongs to the post-asymptomatic-giant-branch (post-AGB) class of metal-deficient stars, lost its metals through a process that took away heavy elements rather than as a part of galactic chemical evolution. Researcher H. Van Winkel and associates found that HD52961's photosphere differs from the star's original composition due to the removal of heavy elements. However, pre-AGB metal deficient stars can still be used to deduce the Milky Way's evolution.

The opacity of matter has been determined at the temperatures and densities found inside stars. L.B. Da Silva and colleagues heated a thin slice of iron with an X-ray laser and then measured the iron's photo-absorption using another X-ray laser. The resulting opacity was strikingly close to the opacity tables that F.J. Rogers and C.A. Iglesias obtained through a supercomputer analysis of atomic physics. The opacity of stellar matter must be estimated indirectly since the stars' interiors cannot be seen.