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Object list indexed by constellation

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Lynx

Binary stars:-

12 Lyncis is about 200 light years away, and the triple system (also known as Struve 948) is an excellent test for telescopes. Companion B is 1.7" from the primary, at PA 69 degrees. The orbit is a long one, 699 years, and as you can see it describes a near-perfect circle.

Companion C is a fixed star at PA 308, separation 8.7". With a medium sized telescope you should be able to resolve all three components.

Struve 958 is another wonderful sight: two 6.0 stars, PA 257 degrees, 4.9". To find it, move south four degrees from 12 Lyncis (passing 13 Lyncis on the way).

Struve 1009 is perhaps even more attractive. Find 15 Lyncis, the brightest star in this corner of the constellation. Then drop down There's a small challenge here, for some observers report the companion to be purplish; others a soft green. This too is a Struve binary (Struve 1062): 5.3, 6.6; PA 315 degrees, 14.7".

Kui 37 is one binary better known by another name: 10 Ursae Majoris. With a proper motion of .507" in a westerly direction (240 degrees) this star has moved from Ursa Major to Lynx but kept its old name. The star is a close visual binary with the companion revolving its primary every 21.9 years. The Epoch 2000 values are: PA 46 degrees and separation a mere 0.6".

Struve 1282 a faint binary system which reflects the same delicate beauty seen in the others listed. This system is located in the eastern region, not far from alpha Lyncis. From alpha Lyncis move west six degrees then north nearly one degree. The right ascension is 8h50m44s, declination 35 degrees, 4 minutes.

The binary is the brighter of the small group of stars found here.

19 Lyncis RA: 07 22.9 Dec.: +55 17 Magnitudes: 5.6 6.5 Separation: 14.8 Position Angle: 315 An almost equally bright pair of a yellow and blue star, fairly separated, and lying in the upper region of the Lynx, that is NE of Capella. The double forms with 4 other stars a big T.

Struve 1282 (Lyn) RA: 08 50.7 Dec.: +35 04 Magnitudes: 7.5 7.5 Separation: 3.6 Position Angle: 279 Two equally bright stars with a clearly deep yellow shade are almost in contact. This attractive pair lies in the southern portion of the Lynx.

Struve 1369 (Lyn) RA: 09 35.4 Dec.: +39 57 Magnitudes: 7.0 8.0 Separation: 24.7 Position Angle: 148 This double contains a nearly orangish yellow primary and a slightly fainter dull yellow secondary, widely separated. The double lies in the southern portion of the Lynx.

Struve 1333 (Lyn) RA: 09 18.4 Dec.: +35 22 Magnitudes: 6.4 6.7 Separation: 1.6 Position Angle: 49 This pair presents a very close double of two equally bright white stars. It lies directly north of Alpha Lyn, the southernmost star of the constellation.

Galaxies:-

NGC 2683 is a spiral galaxy which lies two degrees to the southeast (or a degree northwest of sigma2 Cancri). Seen practically edge-on, it's fairly bright and quite large.

Edited by Doc

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Lyra

Binary stars:

Beta Lyrae RA: 18 50.1 Dec.: +33 22 Magnitudes:3.4 8.6 separation: 46 Position Angle: 149 Beta Lyr is the star W of the Ring Nebula. At least you find a little pink-like companion very wide from the yellow-like primary. There are also other tiny stars in the field, but maybe not physical involved. Beta itself is a variable star climbing from magnitude 3.4 to 4.4 in a shift of only 13 days. Gamma Lyr with magnitude 3.2, the star E of M57, is a good comparison

Delta2-Delta1 Lyrae form a wide binary that may be gravitationally bound despite the great distance. The two have a nice colour contrast, orange and blue. Note that delta2 is the primary: 4.3, while delta1 has a visual magnitude of 5.6. Beta Lyrae is a fixed multiple binary, with a primary of 3.5. AB: 3.5. 8.6; 149º, 46"; AE: 9.9, 318º, 67"; AF: 9.9, 19º, 85".

Epsilon1-Epsilon2 Lyrae: the famous "Double- Double". All four stars are fifth-magnitude. The two principal stars form a very wide binary: PA 173º, separation 208". Each star is itself a double: Epsilon1A-Epsilon1B is a slow binary with 1165 year orbit: 5.0, 6.1; PA 350º and separation 2.6". Epsilon2C-Epsilon2D is about twice as fast, with a period of 585 years: 5.2, 5.5; PA 83.5º, separation 2.3".

Zeta Lyrae is another relatively fixed multiple. The brightest component is D: AD 4.3, 5.9; 150º, 43.7". The other components are fourteen magnitude.

Struve 2470: 6.6, 8.6; 271 degrees, 13.4" and Struve 2474: 6.5, 8.6; 261º, 16.4". The two binaries are found two and a half degrees NE of gamma Lyrae, which is the brightest star in the region. Or, if you can find iota Lyrae, drop south one and a half degrees. It's a sight well worth the detour!

Struve 2474 (Lyr) RA: 19 09.1 Dec.: +34 36 Magnitudes: 6.7 8.8 Separation: 16.2 Position Angle: 262 Together with the double Struve 2470, it is called the 'Other Double Double' in the same constellation of Lyra, just E of the parallelogram. However, this double-double shows all different colors, and the position angles

are the same. Struve 2474, the southern one, consists of a yellow primary and a fainter dull yellow companion, easily separated.

Cluster:-

M56 (NGC 6729) is a globular cluster, very condensed. It is found eight degrees due south of theta Lyrae.

Nebula:-

M57 (NGC 6720) known as the Ring Nebula, is the finest planetary nebula in the skies. The ring itself should be clearly visible in medium scopes, while the fourteen magnitude central star may take a little longer. Burnham gives an excellent discussion on this object. It is located between beta and gamma Lyrae (slightly closer to beta), and is about 4000 light years distant.

NGC 6765 This object is much fainter then the famed ring nebula, but was fairly easy to find, the nebula lies just NNW of a faint horseshoe shaped aterism facing South, and about 3' to the SSW of the planetary lies a 12th magnitude pair of stars pointing directly towards the planetary.

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Monoceros

Binary stars:-

Beta Monocerotis is a wonderful triple star system, especially for smaller telescopes. William Herschel, who discovered it in 1781,

thought it was one of the best he'd ever seen. The three stars form an elegant triangle that doesn't change much, if at all, over time.

Thus the system may be considered "fixed". The visual magnitudes and separations are as follows: AB (4.7, 5.2; 132 degrees, 7.3"), AC: (6.1, 124 degrees, 10").

Epsilon Monocerotis is a fixed binary: 4.5, 6.5; 27 degrees, 13".

15 Monocerotis, also known as S Monocerotis, is another multiple system consisting of six stars. However most of them are extremely faint: AB: 4.8, 7.6; 213 degrees, 2.8". Component C: 9.9, 13 degrees, 17"; D: 9.7, 308 degrees, 41", E: 10, 139 degrees, 74", and F: 7.8, 222 degrees, 56".

Nebula:-

NGC 2237, a large diffuse nebula ("Rosette Nebula") which engulfs the open star cluster NGC 2244 (see below). This nebula actually carries four separate NGC numbers (2237, 2238, 2239, and 2246) although it usually goes under the name of NGC 2237. It takes a large telescope to distinguish the ring shape. Usually all one sees is a ghostly bit of fluff around the star cluster. This nebula has been extensively studied, for it seems to be extraordinarily massive (over 10,000 Suns). Dark matter is woven in and out of the surrounding gases. It is surmised that eventually the gases will coalesce, producing either a new star or perhaps even a whole new system of sun and planets, similar to our own.

Clusters:-

NGC 2244, the open cluster at the centre of the Rosette Nebula, may actually be stars formed out of the Rosette Nebula. However, the central star, 12 Mon (magnitude 6), probably does not belong to the group.

NGC 2264 is a large and bright cluster with associated nebula (The Cone Nebula, so called because of its shape). The brightest star here is the variable S Monocerotis, which is found near the top of the cluster.

M50 (NGC 2323) is surprisingly the only Messier object in this constellation.This is a cluster of about a hundred bright stars, rather tightly grouped, ideal for small telescopes. It can even be seen by the naked eye on a good night. There is a red star near its centre. The cluster is considered to be about 2500 light years away. To find M50 draw a line between Sirius and Procyon; you'll find the cluster about a third of the way up from Sirius.

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Orion

Binary stars:-

Beta Orionis (Rigel) has a 10.4 visual magnitude companion at 202º and a wide 9.5" separation. This is a fixed system.

Lambda Orionis (between Betelgeuse and Bellatrix) is another fixed binary, with a 5.5 companion at PA 43º and 4.4" away.

Theta1 is a complex system of fixed stars. The four brightest form The Trapezium, an outstanding multiple system for small telescopes. AB is at a position angle of 32º and separation 8.8", AC: PA 132º, 12.7", and AD: PA 96º, 21.5".

Theta2 is also a fine binary, a triple system to the southeast of The Trapezium. Component B is a binocular object: 6.4 magnitude at a position angle of 92º and separation 52.5". Component C (8.5) is even wider: PA 98º and separation 128.72".

Sigma Orionis is one of the few orbiting binaries found in Orion. Component B has an orbit of 158 years and is one of the few components that traces a not-quite-perfect circle. That's to say, we see it nearly face on, as a wheel spinning around its hub. The separation never changes much from its current distance of only 0.2". Its 2000.0 position angle is 132º. Much easier to resolve is component E, with a visual magnitude of 6.7, this is a binocular object at a position angle of 61º and separtion of 42".

Zeta Orionis (1.9, 4.0) has a very slow orbit of 1509 years, and is currently at 165º and 2.3" separation.

Delta Orionis RA: 05 32.0 Dec.: -00 18 Magnitudes: 2.2 6.3 Separation: 52.6 Position Angle: 359 This is the westernmost star of the Belt of Orion. It's a very wide double. It consists of a white main star and a much fainter blue component.

Struve 747 (Ori) RA: 05 35.0 Dec.: -06 00 Magnitudes: 4.8 5.7 Separation: 35.7 Position Angle: 223 It lies just 10' SW of Iota Ori, that other double south of the Orion Nebula M42. Two rather equally bright white stars form a considerably wide pair, but still very conspicuous in this star field

Iota Orionis RA: 05 35.5 Dec.: -05 55 Magnitudes: 2.8 6.9 Separation: 11.3 Position Angle: 141 It's located 30' south of the Orion Nebula. A blue little can be seen, considerably close to the brilliant white primary. At its SW lies Struve 747.

Struve 790 RA: 05 46.0 Dec.: -04 16 Magnitudes: 6.4 8.7 Separation: 6.9 Position Angle: 89 A light blue fainter attendant sits considerably close next to the deep yellow main star. It is located not far E from the Orion Nebula

Nebula:-

M42, The Orion Nebula is perhaps the most photographed deep sky object in the heavens, a vast nebula of gas and dust exquisitely lit by surrounding stars. Inside the nebula is the fascinating four-star system known as The Trapezium: theta 1A, 1B, 1C, and 1D - four stars held together by common gravity (actually at least two other stars are part of this complex system.) They are visible in medium sized telescopes and, with the nebula, form one of the most beautiful binary systems in the heavens.

M43 (NGC 1982) is a detached part of the Orion Nebula, with a ninth magnitude central star. A dark lane of gas separates M43 from M42,

although the two are actually part of the same vast cloud.

M78 (NGC 2068) is a faint reflection nebula NE of Alnitak (zeta Ori), that looks best in long-exposure photographs.

The Horsehead Nebula is an intriguing and devilishly difficult dark nebula found just between zeta Orionis and sigma Orionis, visible in medium to large telescopes given the right sky conditions. An H-Beta filter is also helpful.

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Ophiuchus

Binary stars:-

Eta Ophiuchi is a close visual with an orbit of 88 years: 2.9, 3.4; presently the companion is at PA 247º and separation 0.6".

Lambda Ophiuchi is also a rapid binary. 4.2, 5.2; currently the PA is 27º and its separation is 1.5".

Xi Ophiuchi: 4.5, 9.0; PA 50º, separation 3.7".

Rho Ophiuchi: 5.3, 6.0; PA 344º, 3.1".

Tau Ophiuchi: 5.2, 5.9; with an orbit of 280 years. Presently the companion is at PA 282º and separation 1.7".

61 Oph RA: 17 44.6 Dec.: +02 35 Magnitudes: 6.2 6.6 Separation: 20.6 Position Angle: 93 A yellow-like primary and a slightly fainter blue-like secondary are easily split thanks to the wide gap. This star lies in the area of the huge naked eye star cluster of Melotte 186, that is close to the most NE star of the house shape of Ophiuchus. Also the fine pair 70 Oph lies in this area.

36 Ophiuchi is a binary with period of 548 years, of two equal stars: 5.1, 5.1; 148º, 4.9".

70 Ophiuchi is another close binary with a period of 88.3 years. 4.2, 6.0. In 2000.0 the values are PA 149º and separation 3.7".

Struve 2276. This is a very beautiful fixed binary of two fairly faint stars: 7.0, 7.4; PA 257º, separation 6.9".

Clusters:-

M9 (NGC 6333) is the smallest of this group, unresolved except in large instruments. The cluster is found 3.5 degrees SE of eta Ophiuchi. It is considered to be about 26,000 light years away.

In the same field are two more globular clusters: NGC 6342 (1 degree SE) and NGC 6356 (1 degree NE).

M10 (NGC 6254) and M12 (NGC 6218) are nearly identical globular clusters: like tiny explosions of stars with dense cores.

M12 is eight degrees north of zeta Ophiuchi and two degrees east.

M10 is 2.5 degrees SE of M12, with 30 Ophiuchi in the same field.

M14 (NGC 6402) needs a 20-cm telescope to resolve; it's more condensed than the preceding two and slightly fainter.

M19 (NGC 6273) is another very dense cluster, usually described as "oblate", meaning it's a bit egg-shaped. It is about 25000 light years away. M19 is seven degrees due east of Antares (alpha Sco), or two and a half degrees west of the bright double 36 Ophiuchi (and very slightly north, less than a degree).

M62 (NGC 6266) is six degrees SW of theta Oph (and four degrees south of M19); this is another non-circular globular cluster, a little brighter than M19. (Note: Burnham includes this Messier in Scorpius; nearly all other authorities put it in Ophiuchus.)

M107 (NGC 6171) is the faintest of the bunch and quite small. This is one of those "Messiers" that were added to the original list, for some reason. It's three degrees SSW of zeta Ophiuchi.

Nebula:-

B78, the "Pipe Nebula", is a naked eye dark nebula two degrees southeast of theta Ophiuchi, in very rich area of the Milky Way.

Barnard's Star is the most rapidly moving star relative to the solar system, with a proper motion of 10.31", and the second closest star to us, at a distance of 5.91 light years (if you accept the three-star system of alpha Centauri as a unit). This is a red dwarf, with a visual magnitude of only 9.5, and consequently not easily found. Burnham has a finder's chart, page 1253, but since that chart was published the star has moved north 1.1 centimetres. The star is three degrees due east of beta Ophiuchus. The actual location (Epoch 2000) is R.A. 17h58m; Decl. +04 degrees, 34 minutes.

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Pegasus

Binary stars:-

Kappa Pegasi is a very close binary, with an orbit of only 11.52 years: 4.8, 5.3; presently the companion is at PA 132 degrees and separation of only 0.2".

37 Pegasi is another close binary, with an orbit of 140 years: 5.8, 7.1; presently the companion is found at PA 118 degrees and separation of 0.8".

85 Pegasi is a well-known close binary with orbit of 26.27 years: 5.8, 8.9; currently the companion is at PA 149 degrees and separation of 0.8".

Struve 2841 (Peg) RA: 21 54.3 Dec.: +19 43 Magnitudes: 6.4 7.9 Separation: 22.3 Position Angle: 110 It is a considerably wide double with an nearly orange primary and a moderately fainter companion with a subtle greenish tint. This beautiful colored pair lies north of Epsilon Peg, the star with the globular M15 to its NW.

Struve 2848 (Peg) RA: 21 58.0 Dec.: +05 56 Magnitudes: 7.2 7.5 Separation: 10.7 Position Angle: 56 Two almost equally bright pale yellow stars are separated with a fairly wide gap. The companion has a more bluish shade. This double lies SE of Epsilon Peg, the star with the globular M15 to its NW.

Struve 3007 (Peg) RA: 23 22.8 Dec.: +20 34 Magnitudes: 6.6 9.6 Separation: 5.9 Position Angle: 91 It is positioned almost in the middle of the big square pattern. It contains a deep yellow main star and fairly close to it a tiny bluish grey gem.

Clusters:-

M15 (NGC 7078) is one of the finest globular clusters in the heavens, very bright and compact, at 35,000 to 40,000 light years away. It is found four degrees NW of epsilon Pegasi.

Galaxies:-

NGC 7331 is a spiral galaxy resembling the Milky Way Galaxy; it's as if we were looking at outselves from fifty million light years away.

NGC 7479 is a barred spiral galaxy about three degrees due south of alpha Pegasi.

Stephan's Quintet is a noted cluster of galaxies half a degree SSW of NGC 7331. See how many of the five you can spot (three is average, four is good).

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Perseus

Binary stars:-

Epsilon Persei is rather difficult because of the dim companion: 2.9, 8.1; PA 10º, separation 8.8".

Zeta Persei is a multiple system, also with faint companions: AB: 2.9, 9.5; 208º and separation 12.9". C is a dim 11.3, PA 286º and separation 32.8"; D is 9.5, 195º, 94.2".

Eta Persei is a fixed triple system; AB are yellow and blue.

AB: 3.8, 8.5; PA 300º, separation 28.3". C: 9.8; 268º, separation 66.6".

Theta Per RA: 02 44.2 Dec.: +49 14 Magnitudes: 4.1 9.9 Separation: 20 Position Angle: 305 The binary is located W of Alpha Per. A brilliant golden main star and fairly wide next to it a little blue gem. At its east lies the double Struve 304.

Struve 304 (Per) RA: 02 48.8 Dec.: +49 11 Magnitudes: 7.5 10.7 Separation: 25 Position Angle: 288 It lies just E of the other double Theta Per. It includes a white primary with a fainter blue secondary fairly separated

Struve 331 is a splendid fixed binary: 5.4, 6.8; PA 85º, separation 12.1". It's found midway on a line between gamma Persei and tau Persei and just a bit south.

h1123 is a fine wide binary in the middle of M34: 8.5, 8.5; PA 248º, separation 20.0".

56 Per RA: 04 24.6 Dec.: +33 58 Magnitudes: 5.9 8.7 Separation: 4.2 Position Angle: 22 East of Zeta Per, the southernmost star of Perseus, lies a triplet of 3 stars in one line. The northernmost is the other double Struve 533. The southernmost is 56 Per. A bright yellow star is touched by a fainter yellow secondary.

Struve 369 (Per)RA: 03 17.2 Dec.: +40 29 Magnitudes: 6.7 8.0 Separation: 3.5 Position Angle: 28 The binary lies just E of Algol. It's a rather close binary with a yellow primary and a moderately fainter blue companion.

Struve 336 (Per) RA: 03 01.5 Dec.: +32 25 Magnitudes: 6.9 8.4 Separation: 8.4 Position Angle: 8 A slightly fainter light blue sun lies relatively close next to an orangish yellow primary. The double is positioned in the most SW corner of the constellation south of Algol, or E of the Triangle.

Clusters:-

M34 (NGC 1039) is a fine open cluster containing about eighty stars. The cluster is considered about 100 million years old. The cluster is about five degrees WNW of Algol (beta Persei), or more precisely twenty-seven arc minutes west of Algol and two degrees north.

NGC 869 and NGC 884 form the well known "Double Cluster", two open star clusters side by side, easily seen by naked eye or binoculars. The clusters are both considered babies, 869 only being about 6.5 million years old, and 884 about 11-12 million years old.

The easiest way to find them is to form a triangle, using gamma Andromedae and alpha Persei. Then the northern point becomes the twin clusters.

Nebula:-

NGC 1499, The California Nebula, is a gaseous nebula one degree north of zeta Persei, and stretching itself in an east-west direction.

Unfortunately it is extremely faint and difficult to view. In fact binoculars might afford the best chance.

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Pisces

Binary stars:-

Alpha Piscium (Struve 202) has an orbit of 933 years (considerably more than the 720 years previously thought): 4.3, 5.2; currently PA 223 degrees, separation 1.6".

Zeta Piscium (Struve 100) is a fine binary: 5.6, 6.5; 63 degrees, 23" separation.

Eta Piscium is a difficult binary to resolve: 3.5, 11; 36 degrees, 1" separation.

Psi1 Piscium (Struve 88): 5.3, 5.5; 160 degrees, 30" separation.

Struve 61 (65 Piscium) is a splendid binary of equal stars: 6.3, 6.3; 297 degrees, 4.4" separation. The binary is found just on the border with Andromeda. The easiest way to find it is to start from zeta Andromedae, then move north 3 degrees and east half a degree.

35 Psc RA: 00 15.0 Dec.: +08 49 Magnitudes: 6.0 7.6 Separation: 11.6 Position Angle: 148 It lies under the most SE star of the square of Pegasus, just right of the other double 38 Psc. It appears as a wide double with a yellow primary and a fainter blue companion.

38 Psc RA: 00 17.4 Dec.: +08 53 Magnitudes: 7.9 7.8Separation: 4.3 Position Angle: 236 It lies under the most SE star of the square of Pegasus, just left of the other double 35 Psc. It is a close double of equally bright yellow stars.

55 Psc RA: 00 39.9 Dec.: +21 26 Magnitudes: 5.4 8.7 Separation: 6.5 Position Angle: 194 Lies just left of the square of Pegasus, officially in the Pisces regiotn. It's a close double wih a bright orange primary and a much fainter blue secondary.

100 Psc RA: 01 34.8 Dec.: +12 34 Magnitudes: 7.3 8.4 Separation: 15.5 Position Angle: 77 A slightly fainter attendant tries to get away from the primary, keeping a fairly wide gap. This double lies south of the most known galaxy M74 in the Fishes, that is SW of the arc of Aries

Struve 3009 RA: 23 24.3 Dec.: +03 43 Magnitudes: 6.8 8.8 Separation: 7.0 Position Angle: 230 This fine double is located south of the big square of Pegasus, in the westernmost circular asterism of the Fishes. It consists of a clearly orange main star and a two magnitudes fainter purple-like companion, moderately separated

Galaxies:-

M74 (NGC 628) is a spiral galaxy seen face on. It's about 22 million light years away, and one of the faintest Messiers. The larger the scope, the better. Long exposure photographs show two or three loosely-wound spirals `spinning' out from a small bright nucleus.

The galaxy is found 1.5 degrees ENE of eta Piscium

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Sagittarius

Binary stars:-

Nu1 Sagittarii is a fixed binary with faint companion: 5.0, 10.8; PA 97º and separation 2.5".

54 Sgr also catalogued as h 599 is a multiple system: AB: 5.4, 12; PA 274º, separation 38"; AC: 8.9; PA 42º, 45.6". The primary has a reddish tinge to it.

Rho1 and rho2 form a nice triangle with h 2866: AB: 8.0, 8.3; 53º, 23.4" AC: 8.6; 137º, 24".

Nebula:-

M8 (NGC 6523) is a marvellous diffuse nebula known as the "Lagoon Nebula". This naked eye object is considered to be from 3500 to 5100 light years away. A dark band divides the nebula in two. While easily spotted with the eye, there is a wealth of detail that can only be brought out with at least a medium sized scope. The Lagoon Nebula is five degrees west of lambda Sgr and one degree north.

M17 (NGC 6618), the "Swan Nebula" or the "Omega Nebula", and occasionally known as the "Horseshoe Nebula". This nebula resembles the tail of a comet: a bright diffuse trail of light with a bit of a hook on it. It is about 5000 light years away. The Swan Nebula is five degrees north of mu Sgr, and one degree east.

M20 (NGC 6514), the "Trifid Nebula", is another delight, but only with larger scopes, which will bring out the three dark lanes familiar on photographs.

In the same field is M 21, an open cluster of about fifty stars. The Trifid Nebula is found 1.5 degrees north of the Lagoon Nebula.

NGC 6445--I had never seen this gorgeous planetary nebula in Sagittarius before, and I sincerely wondered why. Finding M23 is 2/3 the battle, and it's not a hard one at that. Even at low power two distinct lobes can be seen.

Clusters:-

The open cluster NGC 6530 is contained in the eastern part of the nebula. The young cluster (only several million years old) is nicely contrasted against the nebula.

M18 (NGC 6613) is an open cluster of about twenty stars; a rather undistinguised member of the Messier group found one degree south of M 17.

M21 (NGC 6531) is a rather unspectacular open cluster 0.7 degrees NW of M20.

M22 (NGC 6656) is a fine globular cluster, a highly concentrated group of perhaps five hundred thousand stars in total, about 20,000 light years away. It lies two degrees NE of lambda Sgr.

M23 (NGC 6494) is a pleasantly scattered open cluster of about 120 stars located four degrees northwest of mu Sgr and one degree north.

M24 (no NGC) is a bright "star cloud", which contains the open cluster NGC 6603.

M25 (no NGC) is a bright open cluster but without much interest.

M28 (NGC 6626) is a bright condensed globular cluster, much less spectacular than M 22 but a fine object none the less. It is one degree NW of lambda Sgr.

M54 (NGC 6715) is a globular cluster, difficult to resolve.

M55 (NGC 6809) is another globular cluster, less concentrated than those previously mentioned. It is about 20,000 light years away, and lies between zeta Sgrand theta Sgr: seven degrees east of zeta and one degree south.

M69 (NGC 6637) is a globular cluster of little merit.

M70 (NGC 6637) is another globular cluster, two degrees east of M69. It too is of little interest.

M75 (NGC 6637) is the faintest of globular clusters in this constellation.

Galaxies:-

NGC 6822, "Barnard's Galaxy". Very faint; the larger the scope the better. This irregular dwarf galaxy is about 1.7 million light years away, making it one of the closest of its kind. It's in the same region as 54 Sgr, six degrees northeast of rho Sgr.

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Serpens Caput

Binary stars:-

Beta Serpentis (Struve 1970) is a wide visual yet difficult to observe due to the brightness of the primary compared to the faint companion: 3.0, 9.2; PA 265º, separation 30.8".

Theta Serpentis (Struve 2417) is a wonderful binary of two white stars: 4.0, 4.2; 103º, 22.2".

Struve 2375 is a superb pair: 6.2, 6.6; 116º, 2.4".

STT-360 which has a separation of 1.5"

Delta Serpentis RA: 15 34.8 Dec.: +10 32 Magnitudes: 4.2 5.2 Separation: 3.9 Position Angle: 178 Delta is the star just south of the little triangle forming the snake's head. It has a yellow primary and considerably close to it a yellow secondary, almost equal in brightness. Also look for the double Otto Struve 300 at its NE.

Cluster:-

M5 (NGC 5904) is a spectacular globular cluster, containing a half a million stars. The cluster is quite compact and rather bright; it is about 25,000 light years away, and ten billion years old. The cluster is found eight degrees SW of alpha Serpentis.

Nebula:-

M16 (NGC 6611), "The Eagle Nebula", is a remarkable open star cluster surrounded by a huge nebula, very luminous with dark streaks of dust: a nursery of newly forming stars. Best seen in large scopes; a nebula filter might help. The cluster is fifteen degrees south of eta Serpentis, but an easier way to find it may be to draw a line from eta Serpentis to xi Serpentis, to the SW. Now midway along that line is found the bright star nu Ophiuchi. Draw an imaginary perpendicular out from nu Ophiuchi, southeast. About seven degrees along this line is M16. If this seems a bit complicated, first try locating M17, The Omega Nebula (or Swan Nebula), in Sagittarius. Two and half degrees north is M16

Edited by Doc

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Sextans

Binary stars:-

Gamma Sextantis is a multiple binary. AB is a close double, with orbit of 77.5 years: 5.6, 6.1; 61º, 0.5". C is much fainter and wider: visual magnitude 12; 325º, 36".

Galaxies:-

NGC 3115 is a bright galaxy seen edge-on, looking like a fuzzy flying saucer. It may be over 20 million light years away. The galaxy lies midway between epsilon Sextantis and gamma Sextantis and very slightly north. The easiest way to find it is start from Regulus (alpha Leonis). From this bright star drop south through alpha Sextantis (12.5 degrees) then continue south another 7.5 degrees

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Taurus

Binary stars:-

Theta2 and theta1 form a fixed binary of wide separation, theta2 just below and to the east. Note that theta2 is the primary: 3.4, 3.8; PA 346º and separation 337".

Kappa1 and kappa1 form an easily resolved binary: 4.2, 5.3; PA 328º, separation 5.3".

Sigma2 and sigma1 is another wide fixed binary. And again, sigma2 is the primary: 4.8, 5.2; PA 193º and separation 431".

80 Tauri is a difficult visual binary with an orbit of 189.5 years: 5.5, 8.0; current PA 17º and separation of 1.8" (very nearly its maximum separation).

118 Tauri RA: 05 29.3 Dec.: +25 09 Magnitudes: 5.8 6.6 Separation: 4.8 Position Angle: 204 It lies in the most NE corner of Taurus, rather just below the southernmost star of the pentagon of Auriga. It's a pretty nice fairly close pair of a white primary and a slightly fainter yellow attendant.

Struve 422 is a wide visual binary with an orbit of over 2000 years: 5.9, 8.8; PA 269º, 6.7". It's located at 9º SW of nu Tauri, just north of the brighter 10 Tauri

30 Tau RA: 03 48.3 Dec.: +11 09 Magnitudes: 5.1 10.2 Separation: 9 Position Angle: 59 It's located deep under the Pleiades, W of the main figure of the Bull. The main star is bluish, while the companion is reddish. The companion is strongly fainter, but still easily separated by the moderately wide gap between them.

Struve 495 (Tau)RA: 04 07.7 Dec.: +15 10 Magnitudes: 6.0 8.8 Separation: 3.8 Position Angle: 221 It lies just W of the main figure of the Bull. Two yellow stars, the second one is fainter, are pretty close to each other.

Struve 572 (Tau) RA: 04 38.5 Dec.: +26 56 Magnitudes: 7.3 7.3 Separation: 4.0 Position Angle: 194 Two equal yellow stars not far from each other. This nice duo is located straight up north of Aldebaran.

Struve 742 (Tau) RA: 05 36.4 Dec.: +22 00 Magnitudes: 7.2 7.8 Separation: 3.9 Position Angle: 270 This pair waits directly W of the Crab Nebula M1. It has two yellowish white stars, the component only a bit fainter, and the gap is easily split.

Struve 670 (Tau) RA: 05 16.7 Dec.: +18 26 Magnitudes: 7.7 8.2 Separation: 2.5 Position Angle: 164 It is a challenge to see the fainter companion very close to the brighter primary. The double lies between Zeta, the star near the Crab Nebula M1, and Aldebaran.

Nebula

Just northwest of zeta Tauri is the first of Messier's objects: M1, the Crab Nebula.

M45, The Pleiades. This open cluster of about two hundred stars is only 150 light years away, and considered to be about 600 million years old. It is shaped like a "V", just to the west of Aldebaran.

Hind's Variable Nebula (NGC 1555) This curious deep sky object is located two degrees west of epsilon Tauri, and two degrees north of delta Tauri. First look for the rather dim variable T Tauri. Burnham (Celestial Handbook) has a finder's chart, on page 1833. The star has an irregular variability, from 9 to 13.

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Triangulum

Binary stars:-

6 Trianguli [also listed sometimes as iota Tri] is an attractive binary with colour contrast, yellow and blue: 5.3, 6.9; PA 71º and separation 3.9".

Iota Trianguli RA: 02 12.4 Dec.: +30 18 Magnitudes: 5.3 6.3 Separation: 3.9 Position Angle: 71 It lies just under the triangle. A binary with a yellow and a fainter blue star, nearly touching each other.

Struve 239 (Tri)RA: 02 17.4 Dec.: +28 45 Magnitudes: 7.0 8.0 Separation: 13.8 Position Angle: 211 Like the double Iota Tri, this one also lies just under the triangle. It is a pretty pair of blue and yellow stars.

Galaxies:-

M33 (NGC 598) is a very large but quite faint face-on spiral galaxy sometimes known under the name "Pinwheel Galaxy" since it is said to be slowly rotating in a clockwise motion, making a complete turn probaby every 200 million years. It's seventeen arc minutes west of alpha Trianguli and one degree north; or just about midpoint between alpha Arietis and beta Andromedae (slightly closer to the latter). The galaxy is estimated to be from 2.5 to 3.5 million light years away. Low power scopes, or even binoculars, work best.

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Ursa Major

Binary stars:-

Dubhe (Alpha Ursae Majoris) is a well-known binary, with a close 4.8m companion which orbits every 44.66 years. In 2000 the values are: 1.9, 4.8; PA 214º, separation 0.6".

Phi UMa is even closer these days [PA 243º, separation 0.23"] but the distance is gradually widening. It has a period of 105.5 years.

The two stars are similar in magnitude: 5.3, 5.4, resulting in a combined magnitude of 4.6.

Sigma2 UMa is a much easier binary to resolve; presently the separation is 3.8" at PA 355º. The companion, a rather dim 8.2 visual magnitude, describes a leisurely 1067 year orbit. As with many slowly orbiting binaries, this one has had a variety of calculated periods, although Burnham's "best modern computation [of] 706 years" is now considered out of date.

Xi UMa is an attractive binary [4.3, 4.8] with a fast orbit. This star shouldn't cause too many problems to resolve; its closest point came in 1993 and it too is widening, presently sitting at PA 302º and separation 1.3". The star was designated an RS CVn type variable in 1993.

Zeta UMa, Mizar, is the best of the bunch and probably the easiest to find as well. A multiply system with Alcor, AB form a fixed binary at PA 152º, separation 14.4". Alcor (component C) is a distant 12 minutes east (709").

Mizar was the first binary system to be discovered (in 1650), and is usually the first binary to be found and studied by amateur astronomers. No matter how long you study the stars, coming back to Mizar is always a treat. Both A and B are also spectroscopic binaries (that is, each one has a companion too faint for observation but which shows up when studied spectroscopically). The presence of such a companion is deduced from changes in the doppler shift in the spectral lines of the primary. Although at a great distance from Mizar (perhaps three light years away), Alcor (80 UMa) may be gravitationally bound to this star as it shares the same proper motion. However, most authorities believe the stars only form an optical binary. This is a 3.99 visual magnitude star, 81 light years away. Alcor serves as a good jumping off point to study M101, a spectacular face-on spiral galaxy (see below).

21 Uma RA: 09 25.6 Dec.: +54 01 Magnitudes: 7.8 8.8 Separation: 5.7 Position Angle: 311 It lies W of the rectangle pattern. It is a tiny double, but with contrasting yellow and blue colors. The companion is moderately fainter, but rather close to the main star.

Struve 1520 (UMa) RA: 11 16.1 Dec.: +52 46 Magnitudes: 6.6 7.9 Separation: 12.7 Position Angle: 344 It lies just south of the rectangle pattern of the Great Bear. It contains a yellowish main star and a considerably fainter bluish attendant, easily separated.

Struve 1695 (UMa) RA: 12 56.3 Dec.: +54 06 Magnitudes: 6.0 7.9 Separation: 3.7 Position Angle: 283 It lies SW of Alcor and Mizar. It is a fine double with a fairly bright yellowish main star and very close to it a bluish much fainter attendant.

M40 is the Messier object that really isn't one. In 1764 Messier went looking for an object that had been catalogued as a nebulosity in this area. What he found was two ninth-magnitude binary stars, very close together, which he assumed had been mistakenly catalogued as the nebulosity. However instead of leaving the matter there, he proceeded to catalogue the stars as his No. 40.

Galaxies:-

M81 (NGC 3031) is a superb spiral galaxy, and with M82 in the same field, half a degree to the north, forms a splendid pair. The distance is approximately seven to nine million light years and, as Burnham reports, the galaxy is considered one of the most dense galaxies known, with a total mass of 250 billions suns. A large scope is needed to catch the fine detail in the spiral's arms.

M82 (NGC 3034) floats above M81 like an ethereal UFO; any minute you think it's going to zip away in the night sky.

M101 (NGC 5457) is a vast galaxy, one of the largest known, with open spirals. Although seen face on, it's fairly dim; it takes a large scope and an exceptionally good night to see this nebula at its best.

NGC 3184

NGC 3718

NGC 3198

NGC 2841

Nebula:-

M97 (NGC 3587) often called the "Owl Nebula" for its two dark central areas (revealed only in the largest telescopes) resemble an owl's eyes.The nebula is formed by the still expanding shell of its central star, which is very small and compact, with a surface temperature as much as 85,000 kelvin.

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Ursa Minor

Binary stars:-

Alpha UMi is a well-known double star with a wide ninth magnitude companion: 2.1, 9.1; PA 218º, separation 18.4".

Herschel 2682 (UMi) RA: 13 40.7 Dec.: +76 51 Magnitudes: 6.7 9.7 9.0 Separation: 26.3/45.9 Position Angle: 279/316 This is a real triangle figure. A subtle yellowish main star has a faint pink-like companion, and a bit closer an other fainter purple-like companion. This marvelous triple lies W of the two bright bottom stars of the Little Bear.

No deep space objects

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Vulpecula

Binary stars:-

Alpha Vulpeculae may be only optical (observers differ on this point). AB: 4.6, 6.0; PA 28º, separation 13.7".

16 Vulpeculae is a close binary with nearly equal components: 5.9, 6.3; PA 115º, separation 0.8".

Struve 2525 is a fine binary with orbit of 990 years; the 2000 values are: 8.5, 8.7; PA 291º, 2.1". The binary lies between beta Cygni and 3 Vulpeculae.

Struve 2540 (Vul) RA: 19 33.3 Dec.: +20 25 Magnitudes: 7.3 8.8 Separation: 5.1 Position Angle: 147 This double star lies at one end of the huge binocular star cluster of the Coathanger. It is a fairly close double of a white primary and a considerably fainter blue companion.

Struve 2455 (Vul) RA: 19 06.9 Dec.: +22 10 Magnitudes: 7.4 8.5 Separation: 6.6 Position Angle: 40 A white primary with a yellowish tint, has a slightly fainter blue star at its side, considerably close. Together with the other fine doubles Struve 2457 and 2445, it is found NW of the open star cluster of the Coathanger.

Struve 2457 (Vul) RA: 19 07.1 Dec.: +22 35 Magnitudes: 7.5 9.0 Separation: 10.3 Position Angle: 201 An almost yellowish primary glitters with a not much fainter blue sun, moderately close to it. Together with the other fine doubles Struve 2455 and 2445, it is found NW of the open star cluster of the Coathanger.

Nebula:-

M27 (NGC 6853), "The Dumbbell Nebula" is a noted planetary nebula, large, bright, and oddly shaped, It glows with a faintly green colour.

The nebula is found midway between 12 Vul and 17 Vul and about half a degree to the south. (14 Vul is in the same field, just to the NNW).

Cluster:-

NGC 6940 is an open cluster of about a hundred stars, found just midway between 23 Vul and 32 Vul, and a half degree to the north.

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Hydra

Binary stars:-

Alpha Hydra, Alphard (09h25m.1 -08°26') is a 1.9 magnitude class K3 star about 95 light years distant. The star is an optical double, with a 10th magnitude bluish companion.

Beta Hydrae is a pair of nearly equal stars (4.5, 5) at PA 8º and a separation of 0.9".

Epsilon Hydrae is a multiple binary; four stars can be seen and another has been calculated to exist. Components A and B form a rapid binary with a period of 15.05 years; its orbit is nearly circular. Presently (late February 1996) the companion star has a PA of 166º and separation 0.26". Component C is much easier to resolve, with a period of 990 years. At present it can be found at a PA of 298.5º and separation 2.7".

Chi1 Hydrae is a binary of two similar stars (5.8, 5.8) with an even more rapid orbit. Its period of 7.4 years means an exceedingly difficult binary to resolve. If you've a large enough telescope, you'll find the companion at these values in late February 1996: PA 31º and separation 0.046".

Sigma 1474 is a fixed binary forming a wonderful triple. AB: 6.8, 7.9; 24º and separation 70"; C: 6.9, 23º, 76" separation. To find the binary, locate nu Hydrae then move one degreee northwest. (Just north half a degree is the nearly attractive Sigma 1473.)

Struve 1270 (S1270) consists of a pair of stars, magnitudes 6.4 and 7.4.

54 Hya is an easy double star for small telescopes, consisting of yellow and purple stars of magnitudes 5.2 and 7.1, 150 light years away. 54 Hya is in the tail of Hydra, near gamma and R.

Clusters:-

M48 (NGC 2548). Messier actually gave the wrong location for this star cluster, putting it four degrees north of the current position. But by his description this seems to be the right object. Not terribly spectacular, this is a group of fifty stars, the brightest of which is about 8.8 visual magnitude. The cluster is thought to be about 1700 light years away, and is easily seen in binoculars or small telescope.

M68 (NGC 4590) is a much richer globular cluster of over a hundred thousand stars, resolved in medium-sized telescopes. The cluster lies in a desolate part of the sky. Locate gamma Hydrae then move west to beta Corvi. Now drop down three degrees to the brightest star in this region, a fifth-magnitude star (this is the binary B230: 5.5, 12; 170 degrees, separation 1.3"). M68 is about a half degree to the northeast.

NGC 5694 is an extremely compact globular star cluster, thought to be in the region of 100,000 light years away. The cluster sits just east of the mid-way point between pi Hydrae and sigma Librae, at the border with Hydra. From pi Hydrae move east until you encounter a group of five magnitude stars lined up roughly north-south. These are 54, 55, 56, and 57 Hydrae. NGC 5694 lies one degree west of 57 Hydrae.

Galaxies:-

M83 (NGC 5236) is a spiral galaxy sitting on the Hydra-Centaurus border farther to the east, nearly twenty degrees south of Spica (alpha Virginis). While Burnham says this is considered one of the brightest galaxies with a visual magnitude of about 8, other references give it only a 10. And since it is very diffuse, it may be difficult for those living in northern latitudes.

NGC 3109 is a small irregular galaxy between 4.5 and 4.9 million lightyears away in the direction of the constellation of Hydra. It is the most prominent member of a Local Group subgroup. Other names for this galaxy include h 3221 and GC 2003

Nebula:-

NGC 3242 clearly deserves to be a Messier object. Small but bright, at a visual magnitude of 8.6, this planetary nebula is often called The Ghost of Jupiter because of its slight resemblance (?) to that planet. Also at times called The Eye Nebula, perhaps a closer description. The nebula gives off a soft bluish colour, sometimes described as a "glow", that is clearly visible even in small scopes. The central star may be difficult to resolve: this is an 11.4m star, a blue dwarf considered to be as hot as 60,000 kelvin. The nebula is one of the easiest to find. Just locate mu Hydrae then move south two degrees. Trying to resolve the inner ring could prove difficult. Large telescopes should show the object as resembling an eye, with the central star the pupil. The greenish-blue colour adds to this intriguing sight.

NGC2610 a Planetary nebula in hydra at mag 13.0 size 50.0" x 47.0" Position: RA 08:33.5 DEC -16:09.5. It is pretty faint, pretty small and comet shaped with a star of about 12th magnitude at the tip. Averted vision makes it larger in size. Both the UHC and OIII filters are little help, both increase the contrast of the nebula, but make the star much more difficult to see. In my opinion, the view is better without a filter.

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Virgo

Binary stars:-

Gamma Virginis is a splendid binary of similar 3.5 magnitude stars, with a recently revised orbit of 168.8 years. The 2000.0 values are PA 260º and separation 1.5".

Theta Virginis is a white star with two companions, both rather faint: AB: 4.4, 9.4; PA 343, separation 7.1"; AC: 4.4, 10.4; PA 298º, separation 70".

Phi Virginis is a fixed binary: 4.8, 9.3; PA 110º, separation 4.8". The primary is a delicate yellow.

Rho Virgo: Another double star with magnitude 5.0 and 9.2 respectively. Their separation is 4.7 seconds of arc.

Struve 1719 is a striking binary of nearly equal stars: 7.3, 7.8; PA 1º, separation 7.5". The star is located exactly midway between zeta and gamma Virginis, north about two degrees from a line joining these two stars. Another way to find it would be to form a triangle with zeta, gamma, and delta Virginis. The star is at the centre of this triangle.

Struve 1833 is even more attractive: 7.0, 7.0; PA 172º, separation 5.7". This system is located 2.5º SE of iota Virginis. If using Tirion's SkyAtlas, you'll find two binaries in this region. Struve 1833 is the northern one. (The other is a triple system called b939. See Burnham for its details.)

Struve 1869 is the third of our trio of Struve binaries. Another lovely sight, but a bit of a challenge: 8.0, 9.0; PA 133º, separation 26". To find this one, move southeast of mu Virginis two degrees.

17 Vir Yellow and light orange.

Clusters:-

NGC 5634 bright and pretty large, not compressed globular cluster, easy to find.

Galaxies:-

M 49 (NGC 4472) is a 9th magnitude elliptical giant galaxy visible in 75 mm telescopes or larger under low power. It is one of the brightest members of the Virgo cluster of galaxies.

M 58 (NGC 4579) is a 9th magnitude spiral galaxy with a noticeably brighter core.

M 60 (NGC 4649) appears as a symmetrical round haze, rising to a bright centre. It is a 9th magnitude giant elliptical galaxy.

M 84 (NGC 4374) is an elliptical galaxy discovered in 1781 by Messier, and appears as a round bright and conspicuous haze, rising to a small diffuse nucleus. It appears in the same telescopic field as M 86.

M 86 (NGC 4406) is a Seyfert galaxy showing as a narrow spindle. Seyfert galaxies are active galaxies with a bright nucleus and thought to be related to quasars.

M 87 (NGC 4486) is a fine large round object for small telescopes. Photographs reveal a giant elliptical galaxy with many globular clusters in its halo. A straight jet proceeds from the nucleus giving intense radio emission, making this known to radio astronomers as Virgo A.

The Sombrero galaxy M 104 (NGC4594) is a beautiful spiral galaxy with a large nucleus and a dense lane of dust. It lies about 35 million light years away.

NGC4753 a strange little galaxy full of twisted dark lanes, located 2.7° east of the beautiful double star Porrima (Gamma Virginis).

Quasers:-

Quasar 3C 273 is the brightest known quasar with a magnitude 12.8. It is about 3.5° NE of ? Vir ( Zaniah) and 4.7° NW of ? (gamma) Vir (Porrima). The position of the quasar is RA 12h 29.1m, Dec +2° 03'.

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Cetus

Binary stars:-

Gamma Ceti (Struve 299) is perhaps the finest binary in Cetus. Some observers find a colour contrast, yellow and blue: 3.5, 7.3; PA 294º, separation 2.8".

Nu Ceti: 5.0, 9.5; PA 83º, separation 8".

Struve 186 is a close binary of two equal stars, with an orbit of 170 years: 7.0, 7.0; currently PA 60º and separation 1.1".

Beta 395 is a very rapid visual binary, with orbit of 25 years: 6.3, 6.4; presently PA 289º and separation 0.5".

Galaxies:-

M77 (NGC 1068) is a small spiral galaxy seen face on, one of the so-called Seyfert gallaxies, which means it has a radio source - a feeble example of a quasar. M77 is about 50 million light years away, and is found one degree SE of delta Ceti.

NGC 247 is a large and fairly bright spiral galaxy with compact nucleus. It has a slightly irregular shape on one end where the spiral arm has a hollowed out appearance on long-exposure photographs. It is located about 5 degrees north of its famous neighbor in Sculptor, Galaxy NGC 253. It is about the same size as NGC 253, but two magnitudes fainter. Both galaxies are fairly close to us at 12 million light years.

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Lepus

Binary stars:-

Gamma Lupi is a very close binary with a nearly edge-on orbit whose period is 147 years. Currently the companion is at the greatest distance: PA 274º, separation 0.68".

Epsilon Lupi is also a close binary: 3.4, 5.5; 247º, 0.6".

Eta Lupi is a pleasant fixed binary with slight colour contrast: 3.4, 7.8; 20º, 15".

Kappa1 and kappa2 form a wide fixed binary: 3.9, 5.7; 144º, 27".

Mu Lupi is a multiple system. AB: 5.1, 5.2; 142 degrees, 1.2". The third component is much easier: PA 130º, 24".

Xi1 and xi2 Lupi are a fixed pair. This double is the most attractive binary in Lupus: 5.3, 5.8; 49º, 10.4".

Clusters:-

NGC 5822 is a very large open cluster of about a hundred stars. The cluster is about 6000 light years away, and is located 3º SW of zeta Lupi.

NGC 5986 is a globular cluster about 45,000 light years distant. It is 2.5º WNW of eta Lupi.

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Eridanus

Binary stars:-

Theta1 and theta2 Eridani form an attractive pair: 3.4, 4.5; PA 88º, separation 8.2".

Omicron2 Eridani is an interesting triple system only 15.9 light years away. AB form a very wide pair, with orbit of perhaps 8000-9000 years: 4.5, 9.7; PA 105º, separation 82.8".BC form a close visual binary with orbit of 252 years. The primary is a white dwarf, with about twice the diameter of the earth. The component a red dwarf. In fact omicronB is considered the easiest white dwarf for amateur telescopes. The component C has an extremely small mass, considered to be about 0.2 solar mass. 9.7, 10.8; presently PA 337º and 9.3" separation.

32 Eridani is another attractive pair, with colour contrast - yellow and blue: 5.0, 6.3; 347º, 6.9" separation. 32 Eri is near the northern boundary, 10º west of nu Eri (or about 10º north of gamma Eri).

p Eridani is a visual binary near the southern boundary of the constellation. It has an orbit of 483.7 years: 5.8, 5.8; currently the component is at PA 191º and separation 11.5". The binary is found one degree north of Achernar (alpha Eri).

Galaxies:-

NGC 1232 is a spiral galaxy seen face on. It's 2º NW of tau4 Eri.

NGC 1300 is a splendid barred spiral. It's 2.3º due north of tau4 Eri.

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Sculptor

Binary stars:-

Delta Sculptoris is a multiple system: AB: 4.6, 11.5; 243º, 4". C: 9.5; 297º, 75".

Epsilon Sculptoris is a slow moving binary with an orbit of about 1200 years: 5.4, 8.6; currently 23º, 4.7".

Kappa1 Scl: 6.1, 6.2; 265º, 1.4".

Tau Scl is another slow moving binary; it takes nearly 1900 years to make one revolution: 6.0, 7.1; 340º, 2.1".

Galaxies:-

NGC 55 is a spiral galaxy, seen nearly edge-on. It's located twelve degrees southwest of alpha Scl. The nearest star to this galaxy is alpha Phoenicis, which lies three and a half degrees southeast. This is a member of the so-called Sculptor Group, which is one of the nearest galaxy clusters closest to the Milky Way, at about 8 million light years.

NGC 253 is considered one of the easiest spiral galaxies to observe, apart from M31 in Andromeda. This is perhaps the brighest spiral of the Sculptor Group. It is found five degrees NNW of alpha Sculptoris

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Scorpius

Binary stars:-

Alpha Scorpii is a visual binary which may be difficult to resolve due to the brightness of the primary. Try a moonlight night, which should cut the glare of the brighter star: 1.1, 5.4; PA 274º, separation 2.6". The companion is usually described as green in colour, probably a visual effect created by the red glow of Antares. The star is estimated to orbit its primary every 900 years.

Beta Scorpii. This superb double has a pleasant colour contrast: white and bluish-green. 2.6, 4.9; PA 23º, 13.7".

Nu Scorpii is a multiple system, a "double-double". That is, each of the visible components (AC) is also a primary of a closer component; these are termed AB and CD. AC: 4.4, 6.4; 337º, and 41" separation.AB: 4.4, 5.4; PA 2º, 1.3".CD: 6.3, 8.0; 51º, 2.3".

Xi Scorpii is also a multiple system, a system which also includes the next binary system as well (Struve 1999). Components AB form a close binary with period of 45.7 years. The companion is now gradually drawing away from the primary: PA 308º and separation 0.39".

Sigma Scorpii: a double with faint companion. AB: 2.9, 8.5; PA 273º, separation 20".

Struve 1999 is gravitationally attached to the Xi Scorpii system, although at a distance of about 7000 AU (an "AU"--astronomical unit-- being the distance of the earth from the sun). The binary is found just south of Xi Scorpii, two yellow stars of nearly equal brightness: 7.4, 8.1; 99º, 11.6".

Clusters:-

M4 (NGC 6121) is a rather near globular cluster (6000-10,000 light years) but without a large telescope it will not appear very spectacular. There may be as many as fifty RR Lyrae variables in the cluster. M4 is located just west of Antares, roughly half way to sigma Scorpii.

M6 (NGC 6405) is the second-best cluster of the constellation (after M7). This is an open cluster which sometimes bears the name "The Butterfly Cluster". Its brightest star is BM Scorpii, a sixth-magnitude yellow giant. The cluster is about 1500-2000 light years away.

M7 (NGC 6475) also known as Ptolemy's Cluster, is clearly the best deep sky object of the constellation. This magnificent open cluster is extremely large (two full-moon diameters) and quite bright, being visible even to the naked eye under the right conditions. A scope easily resolves the stars, the brightest twenty-two of which range from 5.6 to 9.0. There are several close visual binaries in the cluster. (See Burnham for these, as well as extensive notes on this cluster.) M7 is 4º NNE of lambda Scorpii. It's about 800 light years away.

M80 (NGC 6093) is a rather faint, very compact, globular cluster in the vicinity of Antares, between this star and beta Scorpii, and more narrowly speaking, nearly midpoint between two 8th-magnitude stars (which are the brightest stars of the region). The cluster is quite distant, some 36,000 light years away, and it takes a very large telescope to study it in detail.

NGC 6231 is a naked-eye open cluster one half degree north of zeta Scorpii (which is in fact a member of the group). This cluster is certainly worthy of being a Messier; while noticeable to the naked eye, binoculars resolve its various members. It's about 5500-6000 light years from us. The stars that make up the cluster are generally supergiants that resemble the Pleiades in miniature. Burnham points out that if this cluster were the same distance as the Pleiades, its stars would outshine the Pleiades "by a factor of about 50 times". The cluster is only part of a much larger, very scattered, cluster called H 12, which is found one degree north. In fact, the stars seen as joining NGC 6231 and H 12 actually form one of the spiral arms of our own galaxy.

Edited by Doc

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Capricorn

Binary stars:

Alpha2 and alpha1Cap form an optical binary of yellow and orange stars: 3.6, 4.2; PA 291º, separation 378". Each star is a visual binary: Alpha1 Capricorni: 4.6, 9.2; 221º, 45.4". Alpha2 Capricorni: 3.5, 9.5; 156º, 154".

Beta Capricorni is a wide visual binary with a nice colour contast, yellow and blue: 3.1, 6; PA 267º, separation 205".

Tau Capricorni is a visual binary with a 95 year orbit: 5.5, 7; PA 107º, separation 0.4". The PA is increasing, the separation is decreasing; at the year 2000 the values will be 123º and 0.2".

Globular cluster:

The only Messier in the constellation is M30 (NGC 7099), a globular cluster about 40,000 light years away. It has a very concentrated centre, with a number of star chains (or strings) from the centre to the periphery. M30 is 3º ESE of zeta Capricorni.

Galaxy:

NGC 6907 a barred spiral galaxy of mag 11.7 and with a apparent diameter of 3.4'.

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