The Caldwell Objects

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35 Dim: 2.8' X 2.1' SB: 13.3 Dist: 300 million light-years Disc: William Herschel, 1785 W. HERSCHEL: [Observed 11 April 1785] Faint. (Η II-391) AMONG THE SILENT DESIRES OF MANY AMATEUR astronomers is the ability to peer ever deeper into the universe. We have, it seems, an innate longing to reach for the "beginning," or at least to better understand it. "Going up that river was like traveling back to the earliest beginnings of the world," said the fictitious explorer Marlow in Joseph Conrad's Heart of Darkness. Visual observers go "up that river" by seeking out fainter and fainter objects, objects that will let them look farther back in time. Theirs is a visual journey spurred on by that same, almost primitive, inner voice that must have inspired explorers of old to conquer uncharted territories. But unlike those Earthbound voyagers, today's amateur astronomers can travel phenomenal distances with the help of their telescopes. Anyone who has seen all the Messier objects has witnessed some remarkably distant galaxies. The farthest Messier objects, those in the Virgo Cluster of galaxies, lie 55 million light-years away. Many of the objects in the Caldwell Catalog take us several steps beyond the Virgo Cluster, but none takes us farther than NGC 4889 (Caldwell 35) in Coma Berenices. By spying this tiny and dim object we thrust our reach 300 million light-years into intergalactic space; the feeble light we detect from the galaxy's pale hulk embarked on its silent journey when the first primitive seed plants sprouted from Earth's bleak and solemn soil and the earliest amphibians crawled out of the water to drag their bellies across our planet's virgin shores. NGC 4889 belongs to the Coma Cluster of 136 GC: Pretty bright, pretty much extended, bright in the middle, a star of magnitude 7 to the north. 4th of 5. NGC: Pretty bright, pretty much extended, bright in the middle, a star of magnitude 7 to the north. galaxies and is the easternmost of the two galaxies that dominate the cluster's center; its near-equal, NGC 4874, is a mere two-tenths of a magnitude fainter and, like NGC 4889, appears to be an intense source of radio emission. The Coma Cluster is a rich, spherical agglomeration of at least 1,000 bright elliptical and S0 galaxies and perhaps 10,000 dwarf galaxies. NGC 4889 itself is a giant elliptical or "cD" galaxy with a compact core, a smooth, lens-shaped body, and an extensive halo. Loosely speaking, the galaxy's structure mimics that of the Coma Cluster itself, for the cluster has a compact core centered on NGC 4889 and NGC 4874, a smooth halo of smaller elliptical and S0 galaxies perhaps 7 million light-years in radius, and an outer envelope, 40 million light-years across, that harbors many of the cluster's spiral galaxies. HST images of NGC 4889 taken in 1998 reveal two prominent companions superimposed on, or embedded within, the galaxy's extended envelope; a peppering of fainter objects also haunt the immediate environs. The HST data are now being used to determine what physical processes were occurring when galaxies were forming within the cluster's core. In 1957 Caltech astronomer Fritz Zwicky identified 804 galaxies with photographic magnitudes brighter than 16.5 within 2⅔° of the Coma Cluster's center. The Millennium Star Atlas shows nearly three dozen of these galaxies within 1° of NGC 4889 and NGC 4874. In 4-inch and smaller telescopes, these near twins are the most obvious members of the Coma Cluster, along with NGC 4921, which shines at Deep-Sky Companions: The Caldwell Objects
magnitude 12.2 some 18' to the east-southeast; the rest of the galaxies in the 2°-wide field are all fainter than 13th magnitude. NGC 4889 lies 2.6° essentially due west of 4thmagnitude Beta (β) Comae Berenices. In the Genesis at 23x NGC 4889 is a small, faint, slightly out-of-round glow with a smooth outer halo that gradually brightens to a sharp core. The galaxy is almost lost in the glare of HD 112887, a 7thmagnitude star 9' to northwest. The harder-to-see NGC 4874 is a swollen spot of haze merely 6.5' south of that same star. At 72x, and with time and much patience, The Caldwell Objects 35 137
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DEEP-SKY COMPANIONS The Caldwell Ob
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DEEP-SKY COMPANIONS The Caldwell Ob
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Contents Foreword by Patrick Moore
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to be more difficult than others, s
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years of thought and observation ar
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XII position, type, angular size, a
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sky and share its splendors. There
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CHAPTER 1 About This Book O N ONE S
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times vog can back up and cause a s
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when there is moisture in the air.
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Herschel's original observations, p
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we use today and to one another? I
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SIMBAD (Set of identifications, Mea
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Caldwell 26. The objects in the Cal
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tion near the edges of the charts).
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nights of observing. Unless otherwi
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CHAPTER 2 The Caldwell Objects 1 1
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Because of its location far from th
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as strongly energized as would be e
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suggested by the patchiness of NGC
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4 NGC 7023 Type: Reflection Nebula
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astronomers found direct evidence o
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and his contemporaries. Why then wa
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6 Cat's Eye Nebula NGC 6543 Type: P
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Eighth-magnitude NGC 6543 is locate
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7 NGC 2403 Type: Mixed Spiral Galax
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according to theory, the gas densit
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8 Ghost’s Goblet NGC 559 Type: Op
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One other thing adds to the cluster
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RA: 22 h 56.8 m Dec: +62° 37' Mag:
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nebula is a near impossibility, eve
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1 0 The Horseshoe Cluster NGC 663 T
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heart of the cluster, dividing it i
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appears to be the edge of a rapidly
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1 2 NGC 6946 Type: Mixed Spiral Gal
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to the west by a row of similarly b
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the south-southwest. NGC 457, howev
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photographs. The cluster's bright "
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play begins at 8:00 p.m., when my e
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ightness by summing the contributio
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jewels. Here are sapphires, rubies,
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15 outer shell falls upon the retin
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"knots" have also been noted by exp
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tight gathering of a half-dozen rou
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1 7 NGC 147 Type: Elliptical Galaxy
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the center. A faint outer halo is a
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1 9 Cocoon Nebula IC 5146 (nebula)
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trickle into the pool surrounding t
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2 0 North America Nebula NGC 7000 T
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Page 107 and 108: 2 1 Box Galaxy NGC 4449 Type: Irreg
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Page 119 and 120: RA: 03 h 19 m 48 s Dec: +41° 30.7'
Page 121 and 122: Through the 4-inch, NGC 1275 is les
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Page 125 and 126: 26 Silver Needle Galaxy NGC 4244 Ty
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Page 129 and 130: Observatory, England) still lists a
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Page 133 and 134: 29 NGC 5005 Type: Mixed Spiral Gala
Page 135 and 136: s h a edges. r p However, Christian
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Page 139 and 140: NGC 7331 is extended much farther t
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Page 147 and 148: 33 Network Nebula; Bridal Veil Nebu
Page 149 and 150: A quarter-second later, the star en
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Page 177 and 178: 4 0 NGC 3626 Type: Lenticular Galax
Page 179 and 180: 40 NGC 4546 in Virgo, NGC 4138 in C
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Page 187 and 188: 4 2 NGC 7006 Type: Globular Cluster
Page 189 and 190: each square arcminute of its disk s
Page 191 and 192: 4 3 Electric Arc NGC 7814 Type: Spi
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Page 197 and 198: 4 5 NGC 5248 Type: Mixed Spiral Gal
Page 199 and 200: of the field. Those living under da
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4 7 NGC 6934 Type: Globular Cluster
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stragglers are stars that appear to
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4 8 NGC 2775 Type: Spiral Galaxy (S
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with a CCD camera — discovered a
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this wreathlike network of dust and
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fuzzy patch of light with the unaid
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known as NGC 2244; and NGC 2239 sho
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At a glance the two stars at the cl
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On four plates taken with the Bruce
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years. A total of 43 star-cluster c
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5 2 NGC 4697 Type: Elliptical Galax
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northeast of the sixth star in the
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53 The Spindle NGC 3115 Type: Lenti
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and the 100-inch telescopes atop Mo
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5 4 NGC 2506 Type: Open Cluster Con
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emerge, followed by a diffuse outer
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perfection than is actually the cas
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jets, like a stream of water from t
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5 6 Pac-Man Nebula NGC246 Type: Pla
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the triple-alpha process, wherein t
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5 7 Barnard's Galaxy NGC 6822 Type:
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to show how the galaxy's western re
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core and limber arms, which, he wro
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esembles Jupiter . . . '" Smyth's f
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years" and suggests amateurs monito
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6 0 Ringtail Galaxy; Rataail Galaxy
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war. X-ray images taken by the Rosa
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W. Sinnott's NGC 2000.0 has a visua
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62 Milkweed Seed Galaxy NGC247 Type
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through the narrow haze. But give t
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was more readily seen in binoculars
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Society. Accepting that distance, w
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any large telescope that can provid
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ought it to our attention in the Fe
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inch the cluster shows a pyramid of
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NGC 253 is the brightest member of
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magnitude stars, one just to the ea
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6 6 NGC5694 Type: Globular Cluster
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you see its core dancing? Its starl
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cosmologist Halton Arp (Max-Planck
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and kinked. All this detail is wrap
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telescope. But seeing it takes more
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streamers begin to appear, but they
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tounding, because NGC 6302 is a mag
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70 Southern Pinwheel NGC300 Type: S
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would John Herschel suddenly fault
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Dunlop discovered NGC 55 with his 9
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even when crossing the meridian. Co
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"nebulous clusters" (Class II); and
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galaxy's disk and halo. NGC 2477 ap
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condensed, almost to the very margi
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The asymmetry remains at high power
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other popular nickname, the Eight-B
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longed look, the object displays a
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times larger than the full Moon. In
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emains of a globular cluster that w
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he classified them accordingly. NGC
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NGC 6231). Under averted vision the
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7 7 Centaurus A NGC5128 Type: Pecul
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Harvard College Observatory's 24-in
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at 16 million light-years. If you s
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78 NGC 6541 Type: Globular Cluster
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seems to fragment into tiny stars,
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sense, evinced by any known cluster
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12th-magnitude double star. The clu
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original with Bayer, but goes back
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Omega Centauri is generally regarde
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glitter all come to mind as the clu
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shattered remains of their diminuti
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It's a nice even disk of l0th-magni
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with the fiery reddish light of hyd
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nebulosity when he viewed the regio
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the two jets of radio-wave-emitting
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pair of tweezers. A fairly bright s
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suggest that our universe may be on
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8 5 Omicron Velorum Cluster IC2391
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Nicolas Louis de Lacaille, however,
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much sky as does the full Moon, tho
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8 7 NGC 1261 Type: Globular Cluster
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timates, making it 2 billion years
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NGC 5822. Don't be surprised if you
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89 S Normae Cluster NGC 6087 Type:
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fact, if you look about 7' southwes
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lowing night fell clear, when Hersc
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NGC 2867 is a nitrogen-rich planeta
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halfway between M37 in Auriga (200
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9 2 Eta Carinae Nebula GC 3372 Type
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anch of cold, dark material. Indeed
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stretch 16 billion km from the cent
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the object was known to some civili
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east, and a dim lip of gas to the s
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1 0 1 NGC 6744 Type: Barred Spiral
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have been identified in NGC 6752's
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ightest spiral arm(s) to the north,
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his maiden voyage of discovery in 1
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simply takes much too much effort t
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very wide double of near-equal inte
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went out and looked at the cluster
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NGC 2516 is 60 million years young
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and contains some 1,890 members, wh
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9 8 Coalsack Cluster NGC 4609 Type:
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it near the Swan? There is a still
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with the naked eye is a challenge.
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1 0 0 Lambda Centauri Cluster Colli
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position updates to (2000.0) R.A. 1
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Eta Carinae Nebula. But remember th
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9th magnitude. Of the latter, 23 ha
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103 1 0 3 Tarantula Nebula; True Lo
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southern-sky explorer Abbe Nicolas
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ters it has had thus far with the g
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ly east of NGC 362 we find the magn
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the eye ever inward and takes your
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1 0 5 Southern Butterfly NGC 4833 T
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stars"). Lacaille also likened NGC
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is about 7' in length, and nearly 2
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evealed a significant blue-straggle
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ightest stars shine around 4th magn
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egion looks cold and disturbing, no
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The galaxy received some incidental
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This entry is obviously in error, b
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7 N G C 4 0 4 T y L p e n : G t a i
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pointed her 7x35 binoculars toward
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13 NGC 288 Type: Globular Cluster C
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your telescope on Eta Sculptoris an
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19 N G C 6 2 8 1 T y O p e C : n l
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C Name Type Con. R.A. Dec Mag. Size
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C Name Type Con. R.A. Dec Mag. Size
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Appendix B Why Messier Did N o t i
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A typical pattern for evening hunti
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Earth turns, the cluster would clim
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Initially Herschel made his living
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of the heavens with it. For his swe
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tube's front end. This meant that t
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Star in Collo Ceti" about the star
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years, Herschel would observe some
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fluid, but added that ages of obser
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Appendix D Photo Credits in order o
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A Abell426, 101 Acrux, 388, 392, 39
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index Caldwell 44, 173, 176-178 Cal
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and nebulae, 271, 274, 362 and open
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Hevelius, Johannes, 72, 81, 452 Hip
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M103, 49-50, 58-59 M110, 77 MACHOs.
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NGC 3324, 369 NGC 3372 (Caldwell 92
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Perseus Cluster, 101 Phi Cas Cluste
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Τ Tarantula Nebula (Caldwell 103),
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The Caldwell Objects

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