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The Caldwell Objects

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4 0<br />

NGC 3626<br />

Type: Lenticular<br />

Galaxy (SO)<br />

Con: Leo<br />

RA:11 h 20 m 04 s<br />

Dec:+18° 21.4'<br />

Mag: 11.0<br />

Dim: 3.0' X 2.2'<br />

SB: 12.5<br />

Dist: 86 million light-years<br />

Disc: William Herschel, 1784<br />

W. HERSCHEL: [Observed 14 March 1784] Pretty bright,<br />

small, a little extended, brighter in the middle. (Η II-52)<br />

NGC 3626 is A CURIOUS OBJECT. AS IT IS ONLY<br />

marginally visible in small telescopes, one might<br />

wonder why Patrick <strong>Caldwell</strong>-Moore selected it<br />

over the wealth of other galaxies in Leo; in fact,<br />

NGC 3626 is the only Leo galaxy in his catalog.<br />

Of course, the <strong>Caldwell</strong> Catalog is not intended<br />

to be a list of 109 visually stunning objects but a<br />

selection of Moore's favorite deep-sky objects,<br />

whether they're telescopically dynamic,<br />

astrophysically intriguing, or visually challenging.<br />

<strong>The</strong> question, then, is how NGC 3626 fits<br />

into the picture.<br />

NGC 3626 is a tiny 3'-wide object that shines<br />

with the light of an 11th-magnitude star. It is the<br />

second-brightest member of a dense gathering of<br />

10 galaxies (ranging in brightness from 10th to<br />

about 13th magnitude) that populates Leo's<br />

triangular hindquarters. All these galaxies are<br />

plotted in the second edition of Sky Atlas 2000.0.<br />

All but two of them (NGC 3691 and NGC 3599)<br />

belong to the Leo Cloud of galaxies, an elongated<br />

archipelago of ten dozen island universes. NGC<br />

3626 is a classic lenticular galaxy whisking away<br />

from us at<br />

GC/NGC: Bright, small, very little extended, suddenly brighter<br />

in the middle.<br />

40<br />

1,473 km per second. Less than 1° southwest of<br />

NGC 3626 lies another lenticular galaxy, NGC<br />

3607, which shines a full magnitude brighter than<br />

our <strong>Caldwell</strong> target. (Why didn't Moore select<br />

that one instead, I wonder?) NGC 3607 also is<br />

part of a nice trio of galaxies, which is easy to<br />

locate. Anyway you can use this grouping as a<br />

steppingstone to NGC 3626.<br />

To find NGC 3626 first locate the 3rd-magnitude<br />

stars Zosma, or Delta (δ) Leonis, and<br />

Chertan, or <strong>The</strong>ta (θ) Leonis, the westernmost<br />

stars in the Lion's hindquarters. <strong>The</strong> aforementioned<br />

trio is just east of the halfway point<br />

between the two stars. If you set your finderscope's<br />

cross hairs on the imaginary halfway<br />

point and use a wide-field eyepiece in your main<br />

telescope, the trio's brightest two galaxies (NGC<br />

3607 and magnitude-10.8 NGC 3608) should be<br />

quite obvious. <strong>The</strong> third trio member, 12thmagnitude<br />

NGC 3605, will also be in the field, a<br />

few arcminutes southwest of NGC 3607. In the 4inch<br />

at 23x all three galaxies pop into view,<br />

though NGC 3607 and 3608 are naturally more<br />

readily visible than NGC 3605.<br />

<strong>The</strong> <strong>Caldwell</strong> <strong>Objects</strong> 159

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