N.G.C., 2621. a=10h 565; 8——64° 42′ ; λ=211° 34′; ß=—61° 9′

Planetary, "stellar," impossible to distinguish from a star except by examination of spectrum.

N.G.C. 3587. a=11h 9m0; 8=+55° 34′; λ=141° 15'; B = +45° 1′

This is the "Owl" nebula. The slit was set on the brightest region in the nebula, about 0:6 NE of the nucleus. The guiding was difficult because of the faintness of the image.

Faint patch of nebulosity; slightly elongated; trace of nucleus; diameter approximately 15", but limits are quite indefinite.

This is a very bright planetary nebula; magnitude 8.5; diameter 10".

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One of Dr. Curtis's photographs with the Crossley reflector, though taken for a different purpose, recorded the image of this nebula near one edge of the plate. The strong nucleus and the elliptic outline of a faint ring apparently symmetrical with reference to the nucleus suggested strongly that this object is in fact a planetary nebula. Its spectrum was accordingly observed visually in the expectation that we should find the well known green nebular bright lines to be present. The visible spectrum of the nucleus is a band of continuous light, upon which the two green bright lines of nebulium are superimposed. We have photographed the spectrum of this object with the 3-pr. 6-in. combination, exposure 13 hours. The nebulium radiations 5007 and 4959A, and the Hẞ radiations are the only features recorded. These radiations are not mono

chromatic; they form bands several Angstrom units in width, and the centers of the three bands are displaced toward the red about 15 units from the normal positions of the corresponding nebular bright lines. The measures of the displacements indicate a radial velocity of recession amounting to 940 kilometers per second. The positions of the maxima of the three bands cannot. be very accurately estimated and the assigned velocity may be in error as much as 30 or 40 kilometers. The bands have about the average relative intensities found in the planetary nebulae, 10:31.

Dr. Curtis simultaneously secured a Crossley photograph with this object centered on the plate and the spiral structure is clearly evident.

The character of the spectrum resembles that of the spiral nebula N.G.C. 1068 (R.A.= 2h 37m6).

This faint nebula is remarkable for the strength of the N, line. The relative intensities of the N,, Hẞ, N, images are about as 11: 3.

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The lines in this spectrum have about their normal relative intensities;
N, N, Hẞ: 10:31.

+83° 7′; λ=107° 20′; ß

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The nebular image is apparently a perfectly round disk about 18 seconds of arc in diameter. On the last four spectrograms secured with the slit in three different positions across the nebula none of the lines show definite evidence of inclination. The axis of rotation may be pointing nearly toward us.

N.G.C. 5189. a= = 13h 26m4; 8=—65° 28′; λ=232° 27′; ß: =-50° 42′ Nebulous field about 1:3 in length, composed of three nebulae. N.G.C. 5189, the following one of the three, is about 20" in diameter and slightly fainter than the spindle-shaped nebula in

This is a large and well known spiral nebula whose spectrum Slipher has observed 23 to have "bright hydrogen lines and faint ones of nebulium superimposed upon an early type star spectrum." Campbell and Paddock observing visually, were unable to see bright lines, but the strong continuous spectrum in the green region appeared to lack uniformity, probably due to presence of faint radiation bands. Slipher's observed radial velocity is +500 km./sec.

Planetary, elongated in north and south direction, 8′′ × 10′′, magnitude 11.

The plates are all fully exposed.

There is no apparent explanation for the large variation in the results from the first two plates, except that the nebular lines are much over-exposed.