Harold Corwin

IC 3254 = NGC 4336 is the most likely explanation for the IC number. However, there is some doubt about this. Here is the story.

The object was discovered by Royal Frost on an Arequipa Bruce 24-inch plate (number 6719, taken the night of 9 May 1904), and is included in his list in HA60 as number 884. He gives a position of 12 18.5 +20 01 (1900) which is northeast of NGC 4336 by about 2.5 arcmin. It falls within an arcminute of a 14th magnitude star.

However, Frost does not mention NGC 4336 anywhere in the section of the paper devoted to his nebulae. In this respect, NGC 4336 is included in the large majority of NGC objects that were just where he expected to find them. In particular, he does not include NGC 4336 in his list of missing NGC objects.

Also, his description is "Plan[etary], R, B, d 0.4'." Because the inner bright part of N4336 is over an arcmin across and is clearly not round -- though it is clearly bright! -- Frost's description does not fit the galaxy very well.

So, it is possible that he was actually describing the star, perhaps with a defect superposed (this could, of course, be checked on the Harvard plate which surely still exists in their collection).

On the other hand, Adelaide Ames -- in her Virgo Cluster catalogue in HA 88, No. 1 -- adopted the identity and gives it explicitly in her Table 1. For this object, she used the same plate that Frost searched 30 years before (Arequipa Bruce plate no. 6719), and she found no other objects within at least 10 arcmin of her position for NGC 4336 (she adopted the NGC position which is a bit off).

Since Ames was a meticulous astronomer (Shapley greatly missed her careful work after her tragically early death by drowning), I'm giving a considerable amount of weight to her decision to make the two objects identical. CGCG and MCG come to the same conclusion, though using only the data presented in the NGC and IC; they almost certainly did not have access to the original plate on which the IC object was found.

So, I've provisionally accepted the identity -- but have also added the star to the position list as a possible candidate for the IC object.

In principle, the plate on which this object was discovered will eventually be scanned as part of the DASCH (Digital Access to a Sky Century @ Harvard) project. However, as of early March 2018, it apparently had not. Someday...

― IC Notes by Harold Corwin

Harold Corwin

NGC 4336 = IC 3254, which see. Frost must have thought that IC 3254 was a new object as he measured its position to be over 2.5 arcmin away from that for NGC 4336. The GC/NGC position itself, from John Herschel's two observations, is even further. (D'Arrest's position is within a few arcsec of the modern position, but John Herschel did not get a copy of d'A's monograph in time to cross-check the GC positions.)

In any case, as I explain in the story for IC 3254, the identity seems likely, so I've adopted it for the main table.

― NGC Notes by Harold Corwin

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