We conclude that, at least for these stars, the mean value of the absolute magnitude increases with the spectral index. This conclusion, however, is not generally valid.
32.
Stars with the greatest radial velocities. There are some kinds of nebulae for which very large values of the radial velocities have been found. With these we shall not for the present deal, but shall confine ourselves to the stars. The greatest radial velocity hitherto found is possessed by the star (040822) of the eighth magnitude in the constellation Perseus, which retires from us with a velocity of 72 sir./st. or 341 km./sec. The nearest velocity is that of the star (010361) which approaches us with approximately the same velocity. The following table contains all stars with a radial velocity greater than 20 sir./st. (= 94.8 km./sec.). It is based on the catalogue of Voute mentioned above.
Regarding their distribution in the sky we find 11 in the galactic equator squares and 7 outside. A large radial velocity seems therefore to be a galactic phenomenon and to be correlated to a great distance from us. Of the 18 stars in consideration there is only one at a distance smaller than one siriometer and 2 at a distance smaller than 4 siriometers. Among the nearer ones we find the star (050744), identical with C. P. D. 5h.243, which was the “second” star with great proper motion. These stars have simultaneously the greatest proper motion and very great linear velocity. Generally we find from column 9 that these stars with large radial velocity possess also a large proper motion. The mean value of the proper motions amounts to 1″.34, a very high value.
In the table we find no star with great apparent luminosity. The brightest is the 10th star in the table which has the magnitude 5.1. The mean apparent magnitude is 7.7. As to the absolute magnitude (M) we see that most of these speedy stars, as well as the stars with great proper motions in [table 3], have a rather great positive magnitude and thus are absolutely faint stars, though they perhaps may not be directly considered as dwarf stars. Their mean absolute magnitude is +3.0.
Regarding the spectrum we find that these stars generally belong to the yellow or red types (G, K, M), but there are 6 F-stars and, curiously enough, two A-stars. After the designation of their type (A2 and A3) is the letter p (= peculiar), indicating that the spectrum in some respect differs from the usual appearance of the spectrum of this type. In the present case the peculiarity consists in the fact that a line of the wave-length 448.1, which emanates from magnesium and which we may find on [plate III] in the spectrum of Sirius, does not occur in the spectrum of these stars, though the spectrum has otherwise the same appearance as in the case of the Sirius stars. There is reason to suppose that the absence of this line indicates a low power of radiation (low temperature) in these stars (compare Adams).
TABLE 4.
STARS WITH THE GREATEST RADIAL VELOCITY.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
| Name | Position | Distance | Motion | Magnitude | Spectrum | ||||||||
| (αδ) | Square | l | b | π | r | μ | W | m | M | Sp | m′ | ||
| sir. | sir./st. | m′ | |||||||||||
| 1 | A. G. Berlin 1366 | (040822) | GD5 | 141° | -20° | 0″.007 | 30.8 | 0″.54 | +72 | 8m.9 | +1m.4 | F0 | 9.4 |
| 2 | Lal. 1966 | (010361) | GD4 | 93 | - 2 | 0.016 | 12.9 | 0.64 | -69 | 7.9 | + 2.3 | F3 | 8.5 |
| 3 | A. Oe. 14320 | (150415) | GB9 | 314 | +35 | 0.035 | 5.9 | 3.75 | +61 | 9.0 | + 5.1 | G0 | 9.9 |
| 4 | C. Z. 5h.243 | (050744) | GE7 | 218 | -35 | 0.319 | 0.6 | 8.75 | +51 | 9.2 | +10.1 | K2 | 10.6 |
| 5 | Lal. 15290 | (074730) | GC6 | 158 | +26 | 0.023 | 9.0 | 1.96 | -51 | 8.2 | + 3.4 | G0 | 9.1 |
| 6 | 53 Cassiop. | (015563) | GC4 | 98 | + 2 | .. | .. | 0.01 | -44 | 5.6 | .. | B8 | 5.5 |
| 7 | A. G. Berlin 1866 | (055719) | GD6 | 159 | - 2 | 0.021 | 9.8 | 0.76 | -40 | 9.0 | + 4.0 | F0 | 9.9 |
| 8 | W Lyræ | (181136) | GC2 | 31 | +21 | .. | .. | .. | -39 | var. | .. | Md | var. |
| 9 | Boss 1511 | (055926) | GD7 | 200 | -20 | 0.012 | 17.0 | 0.10 | +39 | 5.2 | - 1.0 | G5 | 6.4 |
| 10 | ω Pavonis | (184960) | GD11 | 304 | -24 | .. | .. | 0.14 | +38 | 5.1 | .. | K | 6.5 |
| 11 | A. Oe. 20452 | (201721) | GE10 | 351 | -31 | 0.015 | 13.5 | 1.18 | -38 | 8.1 | + 2.4 | G8p | 9.4 |
| 12 | Lal. 28607 | (153710) | GB10 | 325 | +34 | 0.033 | 6.2 | 1.18 | -36 | 7.3 | + 3.3 | A2p | 7.4 |
| 13 | A. G. Leiden 5734 | (161132) | GB1 | 21 | +45 | 0.002 | 89.2 | 0.04 | -35 | 8.3 | - 1.5 | K4 | 9.9 |
| 14 | Lal. 37120 | (192932) | GC2 | 33 | + 6 | 0.050 | 4.1 | 0.52 | -34 | 6.6 | + 3.5 | G2 | 7.6 |
| 15 | Lal. 27274 | (145421) | GB9 | 308 | +34 | 0.013 | 16.2 | 0.79 | +34 | 8.3 | + 2.2 | F4 | 8.9 |
| 16 | Lal. 5761 | (030225) | GD5 | 126 | -28 | 0.039 | 5.1 | 0.86 | -32 | 8.0 | + 4.4 | A3p | 8.1 |
| 17 | W. B. 17h.517 | (172906) | GC12 | 358 | +20 | 0.014 | 14.1 | 0.63 | -31 | 8.6 | + 2.8 | F1 | 9.1 |
| 18 | Lal. 23995 | (124717) | GB8 | 271 | +46 | 0.012 | 17.0 | 0.88 | +30 | 8.2 | + 2.0 | F3 | 8.8 |
| sir. | sir./st. | m′ | |||||||||||
| Mean... | .. | .. | .. | 23°.9 | 0″.041 | 16.7 | 1″.34 | 16.7 | 7m.7 | +3m.0 | F9 | 8.5 | |