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Messier Objects
Chapter1
Chapter2
Chapter3
Chapter4
Chapter5
Chapter6
Appendix

6 Twenty spectacular non-Messier objects

Without question, Messier's catalogue contains many of lhe skys brightest and most glorious deep-sky objects. But there are a host of other exquisite objects that he did not include, either because they were too far south to be seen from his observing location, or because he missed, ignored, or somehow overlooked them. The following are brief descriptions of 20 of my favorite non-Messier objects, in no particular order. I only hope these objects will inspire you to continue scanning the skies for your own celestial treasures.

Why Messier failed to include the Perseus Double Cluster in his catalogue is a mystery This stunning object is among the finest celestial showpieces in the northern sky. Riding high in the winter sky midway between Delta (8) Cassiopeiae and Gamma (7) Persei, this pair of stellar islands looks to the naked eye like a 4th-magn让ude nebula spanning 1 'A moon diameters. Binoculars separate the two clusters, NGC 869 and NGC 884, which are 乞° apart, but a rich-field telescope provides the best view, revealing some 200 suns piled like rubies and diamonds on black velvet. Strings of stars stretch between the couplet, like arms entwining them in an eternal emb; ice. With an estimated age of only a few mrllion years, the Double Cluster is one of the youngest galactic clusters known.

A million sparkling suns packed into an oval disk slightly larger than the full moon's, that's globular cluster Omega Centauri, arguably the finest specimen of its kind. Shining at magnitude 3.5, Omega Centauri appears to the naked eye as a “fuzzy star" or the head of a comet. It is best seen from the southern half of the United States and points farther south; Messier could not have discovered it from Paris; otherwise, he undoubtedly would have praised its beauty The globular looks like a sparkling ball of light in binoculars, while a 4-inch telescope shows myriad blue suns bursting out of an ever-tightening core seems to scintillate with nervous energy. Look for two dark patches on the core.

For those who can dip deep into southern skies, NGC 6397 is a most pleas・ ing target for small telescopes. Under dark skies it is visible to the naked eye as faint "star" on the eastern fringe of the Milky Way, about 10%° south of Theta (0) Scorpii, a 1.9-magnitude lype-F in the Scorpion's tail. Whenever, for pleasure, I'm just scanning that region, which is rich in clusters, the alluring glow of this 6th-magnitude wonder inevitably captures my attention. Through a 4-inch refractor the globular is a clean wash of loosely packed starlight. Many of its members are easily resolved -about two dozen of them shine between magnitude 10 and 12. The cluster also contains many bright red-giant stars that are 500 times more luminous than our sun. At a distance of7,100 light years, NGC 6397 may be the closest globular cluster to our solar system 一 some 2.5 times closer than the great Omega Centauri duster.

An enormous galaxy with three times the number of stars that reside in our Milky Way Galaxy, this celestial giant can be located with binoculars 4%° north of Omega Centauri. You'll find it shining as a conspicuous 7th-magnitude glow with an apparent diameter equal to that of the full moon. Through a telescope NGC 5128 looks like two halves of a broken egg - its whitish shell cracked open by a black absorption nebula. When I first swept up this magnificent object in the 4-inch, I thought I had encoun・ tered a comet with a strong parabolic hood: the dark lane looked like the shadow of that "comet's" nucleus running down the length of its broad (ail. Had Messier found this object, I am certain he would have included it in his catalogue. The galaxy itself is a strong radio emitter, producing a signal L000 times more intense than that of our own Milky Way. Indeed NGC 5128 is among the most peculiar galaxies known, with an explosive nucleus that has jettisoned millions of solar masses of material into space. Astronomers believe Centaurus A is the remains of a cosmic collision between two galaxies, an elliptical and a spiral.

Here is another unfortunate "miss" by Messier and his contemporaries, because undoubtedly NGC 3242 in Hydra is one of the finest examples ofa planetary nebula in the heavens. It shines a full magnitude brighter than M57 (the famous Ring Nebula in Lyra), has an 11.4・magnitude central star within range of the smallest of telescopes, and sports a pale blue disk that is about the same apparent size of Jupiter (thus the Ghost of Jupiter nickname). You can locate NGC 3242 with binoculars nearly 2° south of Mu (卩) Hydrae. Moderate-size telescopes will reveal its ring structure embedded in a larger oval disk of faint light. From dark skies, all its principal features can be seen with a 4-inch telescope. Unlike some planetaries, this one has a high surface brightness, so the nebula can withstand exploration with high magnification. The true diameter of the outer shell may be about 0.6 light year.

For small-telescope users the highly elongated spiral galaxy NGC 253 in Sculptor is rivaled in detail only by M31, the Great Andromeda Galaxy. Although NGC 253 shines only as bright as a 7.6-magnitude star (whose light is spread over an area of 30') its high surface brightness makes it a grand sight through any aperture and with most magnifications. The galaxy displays a highly uniform, though mottled texture. Splashes of dark dust are interspersed with the bright patches. Especially prominent is one dark lane to the west of the nucleus. NGC 253 is the brightest member of the Sculptor Group of galaxies - the closest galaxy cluster to the Local Group, which includes the Milky Way - and is roughly the same size as M31. The object lacks the obvious, starlike core typically seen in many other spiral systems. Indeed, astronomers have found that this galaxy's nucleus seems to be simmering, with gases flowing rapidly away from the nuclear region.

Commonly referred to as the Veil Nebula, the dual arcs of NGC 6960 and NGC 6992 are among the most sought-after sights at summer star parlies. In long-exposure photographs, several extended, arcing streamers appear to float against the Milky Way surrounding the star 52 Cygni. NGC 6960, the brightest arc, can be seen easily in binoculars from a dark sky, and both of these NGC nebulae are within range of 7 x 35 binoculars. They appear ghostly in form, like pale images of fractured chicken bones. The Veil streamers are the detritus of a star that exploded some 40,000 years ago.

With more than 50 bright and colorful suns packed into an area of sky only ]O' across, NGC 4755 ranks high as one of the most spectacular celestial treasures in the southern sky. The cluster is visible to the naked eye as a slightly swollen 4th-magnitude star (Kappa Ik] Crucis) in the most sought-after southern constellation, Crux, the Southern Cross. Binoculars resolve at least nine of its members, which range in brightness from 5.7 to 10.5 magnitude. Small telescopes offer viewers a rich assortment of stellar jewels that shimmer with opalescent light, like a cluster of pearls of various sizes. The bright central region of the Jewel Box Cluster measures about 25 light years in diameter, while a region spanning twice that distance is populated with fainter stellar members. Its nickname comes from an observation by John Herschel, who called it a "superb piece of fancy 疋 wellery/'

Massive and black, the Coalsack Nebula blots out 26 square degrees of Milky Way just east of Alpha (a) Crucis in the Southern Cross; it also lies just south of the rich Jewel Box Cluster. The juxtaposition of these two disparate objects seems almost ironic: to the naked eye the Coalsack looks like the silhouette of a black hole that is greedily consuming the space around it. By comparison the Jewel Box Cluster looks like a cache of stars that have been plucked from the Milky Way. The black cloud lies some 500 or 600 light years away and is one of the closest dark nebulae to our solar system. Telescopically, the cloud looks shredded, as if millions of dark vapors are wending their way though a forest of dim suns. Seen together with the Jewel Box and the Southern Cross, the Coalsack creates one of the most awe-inspiring sights in the heavens.

Nearly 2° east of 17 Comae Berenices lies NGC 4565, the largest and most famous edge-on spiral galaxy in the night sky: In the 4・inch it is not a stunning sight but an elegant one. Shining at lOth-magnitude, the galaxy appears as a slim streak of light with a hazy central bulge that is punctu・ ated by a starlike core. The challenge in small telescopes is to see and trace the dark dust lane that runs along the entire length of this spindle. In photographs taken with large-aperture instruments, this 90,000-light-year-long spiral, which is tilted a mere 4° from edge on, displays dark arcing festoons of dust silhouetted against the bright central bulge. This material was ejected hundreds of light years out of the plane of the galaxy, but gravity is drawing it back in.

Seen exactly edge on, NGC 891 is the unequivocal rival of NGC 4565 in Coma Berenices (just described). However, the lower surface brightness of this 9.9-magnitude galaxy, which lies 3%° east of the fine double star Gamma¹-²(7^1,2) Andromedae, makes it a less attractive sight for small-telescope users. But 1 suppose my loyalty to NGC 891 stems from childhood, because an image of the galaxy used to appear in the closing moments of the television classic Outer Limits, which had a somewhat mystical effect on me. Like NGC 4565, NGC 891 is disrupted by a thick lane of dark matter. In 1940, Carl Seyfert (of Seyfert galaxy fame) discovered that the galaxys dark lane only appears dark because its light is up to a magnitude fainter than the surrounding brightness of the galaxy.

This wonderful but overlooked diffuse nebula in Orion's belt is often portrayed as a challenging telescopic object, but it really is not. True, its pale light is spread over an area as large as the full moon, and it lies a mere 15' northeast of the blazing 1.8・magnitude Zeta (【)Orionis. But from a good dark-sky site it shows clearly in 7 x 35 binoculars. Through the 4-inch, this softly glowing cloud is parted by a thick, serrated dark channel. Thus, NGC 2024 looks very much like a slightly open pair oflips. Despite its distinctive telescopic appearance, I prefer the binocular view because the nebula looks devilishly subtle, like the mysterious smile of the woman portrayed in Leonardo da Vinci's Mona Lisa.

Of the seemingly endless open clusters distributed throughout the Puppis region of the Milky Way band. NGC 2451 has found a special place in my heart. It is a brilliant 3rd-magnitude object 1% moon diameters across with at least 30 colorful stars within the range of binoculars. These stars seem to bum in adoration of the brightest cluster member - the blazing red 3.6-magnitude c Puppis. With a little imagination, the brightest stars can be seen forming a pattern reminiscent of a scorpion with outstretched claws and raised tail. The cluster almost hugs the horizon from midnorth-em latitudes, but it is a stunning sight under southern skies.

A fine 9th-magnitude planetary for small telescopes, NGC 2392 looms in the night sky like a pale apparition on the eastern outskirts of the Gemini Milky Way. It is easily located about 2%° southeast of Delta ⑹ Geminorum and 1'.6 south of an 8th-magnitude field star. With low power it is an abstruse sight, appearing to be little more than a star surrounded by dim haze. But increased magnification and a little patience bring out some titillating details. Most noticeable is the planetary's 10.5-magnitude central star, which seems to bum through a dense 15"-wide shell of greenish blue gas. With patience, that diffuse shell might appear mottled with dark patches. Photographs show these best; they also reveal another ring of gas some 40" away. When seen together, the dark patches in the inner shell and the wispy ring of the outer shell suggest the face of an Eskimo, whose dark eyes are peering out of the hood of a fur-lined parka. As with most planetaries, with averted vision the gas surrounding the bright central star appears to swell. The shell, by the way, is expanding at a rate of about 68 miles per second, so its apparent size is growing about 1" every 30 years. It probably first left the Eskimo's central star some 1,700 years ago, making this planetary one of the youngest known.

Although Collinder 399 is visible to the naked eye as a 4th・magnitude fuzzy patch twice the diameter of the full moon, it looks best in binoculars. Finding it entails hopping just 4° northwest from Alpha (a) Sagitta in the summer Milky Way. The shape of this possible open cluster's dozen or so brightest members looks irresistibly like a coathanger; it is one of the few stellar groupings in the sky that immediately looks like its nickname, the Coathanger. All told, this 200-million-year-old aggregation contains about 40 stars without a hint of concentration. Its brightest member shines at 5th magnitude and is visible to the naked eye.

Just 3° east of blue, 0.1 agnitude Deneb (Alpha |a] Cygni) lies NGC 7000 -the unsung hero of the Cygnus Milky Way. In photographs it appears as a sprawling cloud of glowing gas stars bordered by inky opacity, covering an area four times larger than the full moon, and resembling in shape the outline of the North American continent. One misconception, however, is that the nebula itself is visible only in photographs; this is not the case. In fact, it was discovered visually. Its presence can be inferred with the naked eye as an area of enhanced brightness. Binoculars show it unmistakably as a distinct fan-shaped glow with a faint tail to the south, bordered by a dark gulf to the west. A wide-field telescope under a dark sky brings out the full glory of the nebula, including the dark nebulosity forming the "Gulf of Mexico," and the "East" and "West Coasts/' A nebula filter will boost the contrast of this low-surface-brightness emission nebula, making it easier to discern.

How ironic that I have spent so much time looking for faint details in distant galaxies with my telescope when the most majestic of all galaxies -the Milky Way - reveals itself to me each night with a beauty, shape, and richness of texture that no telescope or spacecraft can capture as well as our naked eyes can.

parent/
Messier Objects
Chapter1
Chapter2
Chapter3
Chapter4
Chapter5
Chapter6
Appendix