Fig. 1.2. — Pleiades optical nebulosity on photo negative prints in the National Geographic Society – Palomar Observatory Sky Survey. Top left: central cluster in red (POSS E) filter. Top right: central cluster in blue (POSS O) filter. Bottom: outer nebulosity in blue light. The vertical line left of center is really a plate boundary.

Fig. 1.3. — Interstellar reddening toward 89 cluster people, from Breger (1986). Stars around the east side from the cluster generally exhibit E(B-V)

.03. Individuals around the west show around two times just as much, as the region from the CO cloud southwest of 23 Tau is eight occasions more reddened. These results correlate well with White’s (1984) measurements of CH +. His 15 stars are marked with Flamsteed and Henry Draper figures. Single underscores represent lower column densities of N (CH + )

5×10 12 cm -2. Double underscores represent greater column densities of N (CH + )

2.5×10 13 cm -2. Plain labels indicate nondetections, which usually have upper limits in conjuction with the lower column density detections. However HD 23512’s limit of N (CH + ) 13 cm -2 isn’t sufficiently small to preclude membership within the greater column density category.

Fig. 1.4. — Fields and pointings of thesis observations: The WISP field is shown by the five&#176 x 1.7&#176 diagonal box. Schmidt fields are 1.1&#176 dotted circles for simplicity, each pointing-pair is proven because just one field. The Eco-friendly Bank mosaic may be the large 19&#176 x 11&#176 irregular box. The VLA mosaic may be the small 2&#176 x 2&#176 square. Filled circles indicate major Pleiads. Coudé feed sightlines are marked with open star symbols.

Fig. 1.5. — Bigger context from the observed fields. The Pleiades live in the northwest corner of Taurus, that is bordered by (clockwise from top) Perseus, Andromeda, Triangulum, Aries, Pisces, Cepheus, Eridanus, Orion, Gemini, and Auriga.

The cluster lies close enough the celestial equator (dotted line) to become easily visible from both hemispheres of the world. Its position some 22&#176 south from the galactic plane (dashed-dotted) puts it in the center of Gould’s belt, a diamond ring of vibrant stars round the sky regarded as a relic of the past star formation episode within this area of the universe. Finally, close closeness towards the plane from the ecliptic (dashed) enables Pleiads to become studied via lunar occultation, but regrettably also complicates observation from the cluster in mid-infrared bands by maximizing background emission from solar zodiacal dust. Stars within this plot are obtained from the Vibrant Star Catalog (Hoffleit Warren 1991 ) and therefore are restricted to