Andrew Cooper
Oct 7, 2023    Kaʻohe, Mauna Kea, HI (map)
28cm f/10 SCT, NexStar 11" GyPSy @ 127x
Seeing: 6 Transparency: 7 Moon: 0%

Small, faint, round with a stellar core, at the center of an east-west 15' arc of 11th to 12th magnitude stars

Harold Corwin

IC 5143 = NGC 7155. This is one of the most southerly of the nebulae found by Lewis Swift. This may account for the large error in declination (25 arcmin), though the error may simply be a 30 arcmin circle reading error, combined with the usual uncertainty that we find in Swift's late positions. The declination, by the way, has the same value in all four lists in which Swift published this object (MN 58, 18, 1897; PASP 9, 224, 1897; Pop. Astron. 5, 427, 1897; and AN 147, 209, 1898 = No. 3517).

In any case, the identity with NGC 7155 is secured by Swift's note about the field stars: "... in line with 2 9m sts sf; 7m * sf." The three stars are there. ESO's suggested galaxy is much too faint, and though SGC's double star is considerably brighter and nearer Swift's nominal position, there are no bright stars to the southeast.

― IC Notes by Harold Corwin

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

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