APPENDIX II

The following list includes a number of double and multiple stars, clusters, and nebulæ, which may be fairly well seen with instruments up to 3 inches in aperture. A few objects have been added on account of their intrinsic interest, which may prove pretty severe tests. The places given are for 1900, and the position-angles and distances are mainly derived from Mr. Lewis's revision of Struve's 'Mensuræ Micrometricæ,' Royal Astronomical Society's Memoirs, vol. lvi., 1906. For finding the various objects, Proctor's larger Star Atlas, though constructed for 1880, is still, perhaps, the most generally useful. Cottam's 'Charts of the Constellations' (Epoch 1890) are capital, but somewhat expensive. A smaller set of charts will be found in Ball's 'Popular Guide to the Heavens,' while Peck has also published various useful charts. The student who wishes fuller information than that contained in the brief notes given below should turn to Gore's exceedingly handy volume, 'The Stellar Heavens.'

The brighter stars are generally known by the letters of the Greek alphabet, prefixed to them by Bayer. When these are used up, recourse is had either to the numbers in Flamsteed's Catalogue, or to those in Struve's 'Mensuræ Micrometricæ.' The Struve numbers are preceded by the Greek Σ. A few of the more notable variable and red stars are included; these are generally marked by capital letters, as V. AQUILÆ. The order of the notes is as follows. First is given the star's designation, then its place in hours and minutes of right ascension and degrees and minutes of declination, N. and S. being marked respectively by + and −; then follow the magnitudes; the position-angles, which are measured in degrees from the north, or bottom point of the field, round by east, south, and west to north again; the distances of the components from one another in seconds of arc; and, finally, short notes as to colour, etc. According to Dawes, one inch aperture should separate the components of a 4·56″ double star, two inches those of a 2·28″, three those of a 1·52″, and so on. If the observer's glass can do this on good nights there is little fault to find with it. Double stars may be difficult for other reasons than the closeness of the components; thus, a faint companion to a bright star is more difficult to detect than a companion which is not far below its primary in brightness. Clusters and nebulæ, with a few exceptions, are apt to prove more or less disappointing in small instruments. The letters of the Greek alphabet are as follows:

α Alpha.η Eta.ν Nu.τ Tau.
β Beta.θ Theta.ξ Xi.υ Upsilon.
γ Gamma.ι Iota.ο Omicron.φ Phi.
δ Delta.κ Kappa.π Pi.χ Chi.
ε Epsilon.λ Lambda.ρ Rho.ψ Psi.
ζ Zeta.μ Mu.σ Sigma.ω Omega.

Andromeda.

M. 31: 0 h. 37 m. + 40° 43′. Great Spiral Nebula. Visible to naked eye near ν Andromedæ. Rather disappointing in small glass.

Σ 205 or γ : 1 h. 58 m. + 41° 51′ : 3-5 : 62′5° : 10·2″. Yellow, bluish-green. 5 is also double, a binary, but a very difficult object at present.

Aquarius.

M. 2 : 21 h. 28 m. − 1° 16′. Globular cluster; forms flat triangle with α and β.

Σ 2909 or ζ : 22 h. 24 m. − 0° 32′ : 4-4·1 : 319·1° : 3·29″. Yellow, pale yellow. Binary.

Aquila.

M. 11 : 18 h. 46 m. − 6° 23′. Fine fan-shaped cluster. Just visible to naked eye.

V : 18 h. 59 m. − 5° 50′. Red star, variable from 6·5 to 8·0.

Argo Navis.

M. 46 : 7 h. 37 m. − 14° 35′. Cluster of small stars, about ½° in diameter.

Aries.

Σ 180 or γ : 1 h. 48 m. + 18° 49′ : 4·2-4·4 : 359·4° : 8·02″. Both white. Easy and pretty.

λ 1 h. 52 m. + 23° 7′ : 4·7-6·7 : 47° : 36·5″. Yellow, pointed to by γ and β.

Auriga.

(Capella) α : 5 h. 9 m. + 45° 54′. Spectroscopic binary; period 104 days.

M. 37 : 5 h. 46 m. + 32° 31′. Fine cluster. M. 36 and M. 38 also fine. All easily found close to straight line drawn from κ to φ Aurigæ.

β : 5 h. 52 m. + 44° 57′. Spectroscopic binary, period 3·98 days.

41: 6 h. 4 m. + 48° 44′ : 5·2-6·4 : 353·7 : 7·90″. Yellowish-white, bluish-white.

Boötes.

Σ 1864 or π : 14 h. 36 m. + 16° 51′ : 4·9-6 : 103·3° : 5·83″. Both white.

Σ 1877 or ε : 14 h. 40 m. + 27° 30′ : 3-6·3 : 326·4° : 2·86″. Yellow, blue. Fine object and good test.

Σ 1888 or ξ : 14 h. 47 m. + 19° 31′ : 4·5-6·5 : 180·4° : 2·70″. Yellow, purple, binary.

Σ 1909 or 44 : 15 h. 0 m. + 48° 2′ : 5·2-6·1 : 242° : 4·32″.

Camelopardus.

V. : 3 h. 33 m. + 62° 19′. Variable, 7·3 to 8·8. Fiery red.

Cancer.

Σ 1196 or ζ : 8 h. 6 m. + 17° 57′ : 5-5·7-6·5 : 349·1°, 109·6° : 1·14″, 5·51″. Triple ; 5 and 5·7 binary, period 60 years; 6·5 revolves round centre of gravity of all in opposite direction.

Σ 1268 or ι : 8 h. 41 m. + 29° 7′ : 4·4-6·5 : 307° : 30·59″. Yellow, blue.

Præsepe: Cluster, too widely scattered for anything but lowest powers.

Canes Venatici.

Σ 1622 or 2 : 12 h. 11 m. + 41° 13′ : 5-7·8 : 258° : 11·4″. Gold, blue.

Σ 1645 : 12 h. 23 m. + 45° 21′ : 7-7·5 : 160·5° : 10·42″. White. Pretty, though faint.

Σ 1692, 12, or α : 12 h. 51 m. + 38° 52′ : 3·1-5·7 : 227° : 19·69″. Cor Caroli. White, violet.

M. 51 : 13 h. 26 m. + 47° 43′. Great spiral. 3° S.W. of η Ursæ Majoris.

M. 3 : 13 h. 38 m. + 28° 53′. Fine globular cluster; on line between Cor Caroli and Arcturus, rather nearer the latter.

Canis Major.

M. 41 : 6 h. 43 m. − 20° 38′. Fine cluster, visible to naked eye, 4° below Sirius.

Canis Minor.

(Procyon) α : 7 h. 34 m. + 5° 30′ : 0·5-14 : 5° 4·46″. Binary, companion discovered, Lick, 1896, only visible in great instruments.

Capricornus.

α : 20 h. 12 m. − 12° 50′ : 3·2-4·2. Naked eye double, both yellow.

M. 30 : 21 h. 35 m. − 23° 38′. Fairly bright cluster.

Cassiopeia.

Σ 60 or η : 0 h. 43 m. + 57° 18′ : 4-7 : 227·8° : 5·64″. Binary; period about 200 years.

Σ 262 or ι : 2 h. 21 m. + 66° 58′ : 4·2-7·1-7·5 : 250°, 112·6° : 1·93″, 7·48″. Triple.

H. vi. 30 : 23 h. 52 m. + 56° 9′. Large cloud of small stars.

Σ 3049 or σ : 23 h. 54 m. + 55° 12′ : 5-7·5 : 325·9° : 3·05″. Pretty double, white, blue.

Cepheus.

κ : 20 h. 12 m. + 77° 25′ : 4-8 : 123° : 7·37″. Yellowish-green.

Σ 2806 or β : 21 h. 27 m. + 70° 7′ : 3-8 : 250·6° : 13·44″. White, blue.

S : 21 h. 36 m. + 78° 10′. Variable, 7·4 to 12·3. Very deep red.

Σ 2863 or ξ : 22 h. 1 m. + 64° 8′ : 4·7-6·5 : 283·3°: 6·87″. Yellow, blue.

δ : 22 h. 25 m. + 57° 54′ : variable-5·3 : 192° : 40″. Yellow, blue. Primary varies from 3·7 to 4·9. Period, 5·3 days. Spectroscopic binary.

Σ 3001 or ο : 23 h. 14 m. + 67° 34′ : 5·2-7·8 : 197·3° : 2·97″. Yellow, yellowish-green.

Cetus.

(Mira) ο : 2 h. 14 m. − 3° 26′. Variable. Period about 331 days. Maxima, 1·7 to 5; minima, 8 to 9. Colour, deep yellow to deep orange.

Σ 281 or ν : 2 h. 31 m. + 5° 10′ : 5-9·4 : 83·1°: 7·74″. Yellow, ashy.

Σ 299 or γ : 2 h. 38 m. + 2° 49′ : 3-6·8 : 291° : 3·11″. Yellow, blue, slow binary.

Coma Berenices.

Σ 1657 or 24 : 12 h. 30 m. + 18° 56′ : 5·5-7 : 271·1° : 20·23″. Orange, blue.

M. 53 : 13 h. 8 m. + 18° 42′. Cluster of faint stars.

Corona Borealis.

Σ 1965 or ζ : 15 h. 36 m. + 36° 58′ : 4·1-5 : 304·3° : 6·15″. White greenish.

R : 15 h. 44 m. + 28° 28′. Irregularly variable, 5·5 to 10·1.

Σ 2032 or σ : 16 h. 11 m. + 34° 6′ : 5-6·1 : 216·3° : 4·80″. Yellow, bluish. Binary, period about 400 years.

Corvus.

δ : 12 h. 25 m. − 15° 57′ : 3-8·5 : 214° : 24·3″. Yellow, lilac.

Crater.

R. : 10 h. 56 m. − 17° 47′. Variable. About 8 magnitude. Almost blood-colour.

Cygnus.

Σ 2486 : 19 h. 9 m. + 49° 39′ : 6-6·5 : 218·2° : 9·63″. 'Singular and beautiful field' (Webb).

(Albireo) β : 19 h. 27 m. + 27° 45′ : 3-5·3 : 55° : 34·2″. Orange-yellow, blue. Easy and beautiful.

Σ 2580 or χ : 19 h. 43 m. + 33° 30′ : 4·5-8·1 : 71·6° : 25·50″. 4·5 is variable to 13·5. Period 406 days.

Z : 19 h. 58 m. + 49° 45′. Variable, 7·1 to 12. Deep red.

RS : 20 h. 10 m. + 38° 27′. Variable, 6 to 10. Deep red.

U : 20 h. 16 m. + 47° 35′. Variable, 7 to 11·6. Very red.

V : 20 h. 38 m. + 47° 47′. Variable, 6·8 to 13·5. Very red.

Σ 2758 or 61 : 21 h. 2 m. + 38° 13′ : 5·3-5·9 : 126·8° : 22·52″. First star whose distance was measured.

RV : 21 h. 39 m. + 37° 33′. Variable, 7·1 to 9·3. Splendid red.

Σ 2822 or μ : 21 h. 40 m. + 28° 18′ : 4-5 : 122·2° : 2·29″. Fine double; probably binary.

Delphinus.

Σ 2727 or γ : 20 h. 42 m. + 15° 46′ : 4-5 : 269·8° : 10·99″. Yellow, bluish-green.

V : 20 h. 43 m. + 18° 58′. Variable, 7·3 to 17·3. Period 540 days. Widest range of magnitude known.

Draco.

Σ 2078 or 17 : 16 h. 34 m. + 53° 8′ : 5-6 : 109·5° : 3·48″. White.

Σ 2130 or μ : 17 h. 3 m. + 54° 37′ : 5-5·2 : 144·2° : 2·17″. White.

H. iv. 37 : 17 h. 59 m. + 66° 38′. Planetary nebula, nearly half-way between Polaris and γ Draconis. Gaseous; first nebula discovered to be so.

Σ 2323 or 39: 18 h. 22 m. + 58° 45′ : 4·7-7·7-7·1 : 358·2°, 20·8° : 3·68″, 88·8″. Triple.

ε : 19 h. 48 m. + 70° 1′ : 4-7·6 : 7·5° : 2·84″. Yellow, blue.

Equuleus.

Σ 2737 or ε : 20 h. 54 m. + 3° 55′ : 5·7-6·2-7·1 : 285·9°, 73·8° : 0·53″, 10·43″. Triple with large instruments.

Eridanus.

Σ 518 or 40 or 0^2 : 4 h. 11 m. − 7° 47′ : 4-9-10·8 : 106·3°, 73·6° : 82·4″, 2·39″. Triple, close pair binary.

Gemini.

M. 35 : 6 h. 3 m. + 24° 21′. Magnificent cluster; forms obtuse triangle with μ and η.

Σ 982 or 38 : 6 h. 49 m. + 13° 19′ : 5·4-7·7 : 159·7° : 6·63″. Yellow, blue. Probably binary.

ζ : 6 h. 58 m. + 20° 43′. Variable, 3·8 to 4·3. Period 10·2 days. Non-eclipsing binary.

Σ 1066 or δ : 7 h. 14 m. + 22° 10′ : 3·2-8·2 : 207·3° : 6·72″. Pale yellow, reddish.

(Castor) α : 7 h. 28 m + 32° 7′ : 2-2·8 : 224·3° : 5·68″. White, yellowish-green. Finest double in Northern Hemisphere.

Hercules.

M. 13 : 16 h. 38 m. + 36° 37′. Great globular cluster, two-thirds of way from ζ to η.

Σ 2140 or α : 17 h. 10 m. + 14° 30′ : 3-6·1 : 113·6° : 4·78″. Orange-yellow, bluish-green. Fine object.

Σ 2161 or ρ : 17 h. 20 m. + 37° 14′ : 4-5·1 : 314·4° : 3·80″. 'Gem of a beautiful coronet' (Webb).

M. 92 : 17 h. 14 m. + 43° 15′. Globular cluster; fainter than M. 13.

Σ 2264 or 95 : 17 h. 57 m. + 21° 36′ : 4·9-4·9 : 259·7° : 6·44″. 'Apple-green, cherry-red' (Smyth), but now both pale yellow.

Σ 2280 or 100 : 18 h. 4 m. + 26° 5′ : 5·9-5·9 : 181·7° : 13·87″. Greenish-white.

Hydra.

Σ 1273 or ε : 8 h. 41 m. + 6° 48′ : 3·8-7·7 : 231·6° : 3·33″. The brighter star is itself a close double.

V : 10 h. 47 m. − 20° 43′. Variable, 6·7 to 9·5. Copper-red.

W : 13 h. 44 m. − 27° 52′. Variable, 6·7 to 8·0. Deep red.

Lacerta.

Leo.

Σ 1424 or γ : 10 h. 14 m. + 20° 21′ : 2-3·5 : 116·5° : 3·70″. Fine double, yellow, greenish-yellow.

Σ 1487 or 54 : 10 h. 50 m. + 25° 17′ : 5-7 : 107·5° : 6·38″. Greenish-white, blue.

Σ 1536 or ι : 11 h. 19 m. + 11° 5′ : 3·9-7·1 : 55·0° : 2·36″. Yellow, blue.

Leo Minor.

Lepus.

R : 4 h. 55 m. − 14° 57′. Variable, 6·7 to 8·5. Intense crimson.

Libra.

M. 5 : 15 h. 13 m. + 2° 27′. Globular cluster, close to star 5 Serpentis. Remarkable for high ratio of variables in it—1 in 11.

Lynx.

Σ 948 or 12 : 6 h. 37 m. + 59° 33′ : 5·2-6·1-7·4 : 116°, 305·8° : 1·41″, 8·23″. Triple, greenish, white, bluish.

Σ 1334 or 38 : 9 h. 13 m. + 37° 14′ : 4-6·7 : 235·6° : 2·88″. White blue.

Lyra.

T : 18 h. 29 m. + 36° 55′. Variable, 7·2 to 7·8. Crimson.

(Vega) α : 18 h. 34 m. + 38° 41′ : 1-10·5 : 160° : 50·77″. Very pale blue. The faint companion is a good test for small telescopes. Vega is near the apex of the solar way.

ε1 : 18 h. 41·1 m. + 39° 30′ : 4·6-6·3 : 12·4° : 2·85″. Pale yellow, pale orange yellow
ε
ε2 : 4·9-5·2 : 127·3° : 2·15″. Both pale yellow.

ζ : 18 h. 41 m. + 37° 30′ : 4·2-5·5 : 150° : 43·7″. Easy, both pale yellow.

β : 18 h. 46 m. + 33° 15′ : 3-6·7 : 149·8° : 45·3″. 3 variable, 12·91 days. Spectroscopic binary.

M. 57 : 18 h. 50 m. + 32° 54′. Ring Nebula, between β and γ. Faint in small telescope. Gaseous.

Monoceros.

Σ 919 or 11 : 6 h. 24 m. − 6° 57′ : A 5-B 5·5-C 6 : AB 131·6° : 7·27″ : BC 105·7° : 2·65″. Fine triple.

Σ 950 or 15 : 6 h. 35 m. + 10°·0′ : 6-8·8-11·2 : 212·2°, 17·9° : 2·69″, 16·54″. Triple, green, blue, orange.

Ophiuchus.

ρ : 16 h. 19 m. − 23° 13′ : 6-6 : 355° : 3·4″.

39 : 17 h. 12 m. − 24° 11′ : 5·5-6 : 358° : 15″. Pale orange, blue.

Σ 2202 or 61 : 17 h. 40 m. + 2° 37′ : 5·5-5·8 : 93·4° : 20·68″. White.

Σ 2272 or 70 : 18 h. 1 m. + 2° 32′ : 4·5-6 : 178° : 2·10″. Yellow, purple. Rather difficult.

Orion.

(Rigel) β : 5 h. 10 m. − 8° 19′ : 1-8 : 202·2° : 9·58″. Bluish-white, dull bluish. Fair test for small glass.

δ : 5 h. 27 m. − 0° 23′ : 2-6·8 : 359° : 52·7″. White, very easy.

Σ 738 or λ : 5 h. 30 m. + 9° 52′ : 4-6 : 43° 1′ : 4·55″. Yellowish, purple. Pretty double.

θ : 5 h. 30 m. − 5° 28′ : 6-7-7·5-8. The 'Trapezium' in the Great Nebula.

M. 42 : 5 h. 30 m. − 5° 28′ : 6-7-7·5-8. Great Nebula of Orion.

Σ 752 or ι : 5 h. 30 m. − 5° 59′ : 3·2-7·3 : 141·7° : 11·50″. White, fine field.

σ : 5 h. 34 m. − 2° 39′. Fine multiple, double triple in small glass.

ζ : 5 h. 36 m. − 2° 0′ : 2-6 : 156·3° : 2·43″. Yellowish-green, blue.

U : 5 h. 50 m. + 20° 10′. Variable, 5·8-12·3. Period 375 days.

Pegasus.

M. 15 : 21 h. 25 m. + 11° 43′. Fine globular cluster, 4° N.E. of δ Equulei.

Perseus.

H. VI. 33·34 : 2 h. 13 m. + 56° 40′. Sword-handle of Perseus. Splendid field.

M. 34 : 2 h. 36 m. + 42° 21′. Visible to naked eye. Fine low-power field.

Σ 296 or θ : 2 h. 37 m. + 48° 48′ : 4·2-10-11 : 299°, 225° : 17·4″, 80″. Triple.

Σ 307 or η : 2 h. 43 m. + 55° 29′ : 4-8·5 : 300° : 28″. Orange-yellow, blue.

(Algol) β : 3 h. 2 m. + 40° 34′. Variable, 2·1 to 3·2. Period 2·8 days. Spectroscopic eclipsing binary.

Σ 464 or ζ : 3 h. 48 m: + 31° 35′ : 2·7-9·3 : 206·7° : 12·65°. Greenish-white, ashy. Three other companions more distant.

Σ 471 or ε : 3 h. 51 m. + 39° 43′ : 3·1-8·3 : 7·8° : 8·8″. White, bluish-white.

Pisces.

Σ 12 or 35 : 0 h. 10 m. + 8° 16′ : 6-8 : 150° : 12″. White, purplish.

Σ 88 or ψ : 1 h. 0·4 m. + 20° 56′ : 4·9-5 : 160° : 29·96″. White.

Σ 100 or ζ : 1 h. 8 m. + 7° 3′ : 4·2-5·3 : 64° : 23·68″. White, reddish-violet.

Σ 202 or α : 1 h. 57 m. + 2° 17′ : 2·8-3·9 : 318° : 2·47″. Reddish, white.

Sagitta.

Sagittarius.

M. 20 : 17 h. 56 m. − 23° 2′. The Trifid Nebula.

Scorpio.

β : 15 h. 59·6 m. − 19° 31′ : 2-5 : 25° : 13·6″. Orange, pale yellow.

(Antares) α : 16 h. 23 m. − 26° 13′ : 1-7 : 270° : 3″. Difficult with small glass.

Scutum Sobieskii.

M. 24 : 18 h. 12 m. − 18° 27′. Fine cluster of faint stars on Galaxy.

M. 17 : 18 h. 15 m. − 16° 14′. The Omega Nebula. Gaseous.

R : 18 h. 42 m. − 5° 49′. Irregular, variable, 4·8 to 7·8.

Serpens.

Σ 1954 or δ : 15 h. 30 m. + 10° 53′ : 3·2-4·1 : 189·3° : 3·94″. Yellow, yellowish-green, binary.

Σ 2417 or θ : 18 h. 51 m. + 4° 4′ : 4-4·2 : 103° : 22″. Both pale yellow.

Sextans.

Taurus.

Σ 528 or χ : 4 h. 16 m. + 25° 23′ : 5·7-7·8 : 24·2° : 19·48″. White, lilac.

Σ 716 or 118 : 5 h. 23 m. + 25° 4′ : 5·8-6·6 : 201·8 : 4·86″. White, bluish-white.

M. 1 : 5 h. 28 m. + 21° 57′. The Crab Nebula. Faint in small glass.

Triangulum.

Σ 227 or ι : 2 h. 7 m. + 29° 50′ : 5-6·4 : 74·6°: 3·79″. Yellow, blue, beautiful.

Ursa Major.

Σ 1523 or ξ : 11 h. 13 m. + 32° 6′ : 4-4·9 : 137·2° : 2·62″. Yellowish, binary. Period 60 years.

Σ 1543 or 57 : 11 h. 24 m. + 39° 54′ : 5·2-8·2 : 2·1° : 5·40″. White, ashy.

(Mizar) ζ : 13 h. 20 m. + 55° 27′ : 2·1-4·2 : 149·9° : 14·53″. Fine pair, yellow and yellowish-green. Alcor, 5 magnitude in same field with low power, also 8 magnitude star.

Ursa Minor.

(Polaris) α : 1 h. 22 m. + 88° 46′ : 2-9 : 215·6° : 18·22″. Yellow, bluish, test for 2-inch.

Virgo.

Σ 1670 or γ : 12 h. 37 m. − 0° 54′ : 3-3 : 328·3° : 5·94″. Both pale yellow. Binary, 185 years.

Vulpecula.

M. 27 : 19 h. 55 m. + 22° 27′. The Dumb-bell Nebula. Just visible with 1¼-inch. Gaseous.