Harold Corwin

IC 4407 is perhaps identical with NGC 5324. The IC object was discovered by W.H. Finlay on 20 Sept 1883 with one or the other of the 6- or 7-inch equatorial refractors at the Royal Observatory at the Cape of Good Hope. Finlay's position is the crude result of a reading of the setting circles, 14h 14m, -5d 21m for 1860. The short note in the March 1898 issue of MNRAS gives no description for the nebula.

We've usually assumed that the position is 2 minutes of time off, and that Finlay's nebula is MCG -01-37-005. But, as was pointed out to me by Courtney Seligman, Malcolm Thomson has suggested that this galaxy is too faint for Finlay to have seen. Indeed, Malcolm asked fellow observer Curtis Croulet to search for the MCG galaxy with a 12.5-inch reflector; Croulet was unable to see the small spiral.

My suspicion is that Finlay's RA is wrong; telescopes on fixed equatorial mounts are usually set so that the declination is accurate, but the RA depends on an accurate clock setting. So I searched for digit errors in the RA. If the RA of Finlay's object is actually 13h 44m -- just 30 minutes west of his printed place -- then it is likely that NGC 5324 is his object. The declinations are the same, and the NGC object is certainly bright enough for Finlay to have seen.

None of this is conclusive, of course, but lacking any other reasonable candidates -- there are none at other positions suggested by digit errors in declination as well as right ascension -- NGC 5324 at least rates a table entry with question marks.

― IC Notes by Harold Corwin

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