NGC 3643
DSS image of NGC 3643
Overlaid DSS image of NGC 3643, 30' x 30' with north at top and west to the right

Aladin viewer for the region around NGC 3643
MCG+01-29-036, PGC 34802, SDSS J112124.99+030050.1

Type  Galaxy
Magnitude  14.1
Size  0.64' x 0.32' @ 100°
Right Ascension  11h 21' 25.0"  (2000)
Declination  3° 0' 50" N
Constellation  Leo
Description  eF, vS
Classification  SB0
Observing Notes

Harold Corwin

NGC 3643, NGC 3644 = IC 684, and NGC 3647. Even though Marth's positions for NGC 3643, NGC 3644, and NGC 3647 are pretty good, this has not prevented later observers from misidentifying these at one time or another. In particular, Bigourdan's "NGC 3647" is a star, and he labeled NGC 3644 as "new" (his positions for both are accurate). Thus, this latter galaxy received an IC number (684) as well as its NGC number. Kobold got the right galaxies for N3643 and NGC 3644, but both he and Wirtz list NGC 3644 as "NGC 3645(?)" (though Kobold does have an erratum saying that though the identity is uncertain it is probably NGC 3644). RNGC has misidentified NGC 3643 and NGC 3645 (which see), and CGCG makes yet another object in the group NGC 3645.

Finally, just about everyone, including me, has misidentified NGC 3647. There are four CGCG galaxies here. Most of us have chosen CGCG 039-141 -- the easternmost -- but the brightest (by half a magnitude) of the three is CGCG 039-135, the westernmost. Steve Gottlieb has gently reminded us that brighter objects are usually easier to see than fainter ones. Even with a 48-inch reflector, Marth called this one an "eF neb *." And he saw only one object here, not four, so the obvious choice is the brightest.
NGC Notes by Harold Corwin
Other Data Sources for NGC 3643
Nearby objects for NGC 3643

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

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NGC 3643