Notes

From Steve Gottlieb’s NGC Notes: https://adventuresindeepspace.com/index.html

NGC 1932:

John Herschel discovered NGC 1932 + 1933 = h2841 on 2 Nov 1834 and recorded “B; eS; bM; 10″.” On a later sweep he called it a “double nebula; pos 260°, 80″. The first pB; S; R; 30″. The second eF; R; almost stellar.” The second nebula was only recorded on one sweep (#538) out of 5 total. Based on this description, though, JH assigned two GC numbers (1138 and 1139), which became NGC 1932 and 1933. But there is only a single cluster at his position and Harold Corwin identifies NGC 1932 with a mag 13 star just west of the cluster.

Eric Lindsay, in “Some NGC objects in the Large Magellanic Cloud” [1964IrAJ….6..286L] writes “[NGC 1932 and NGC 1933] seem to be the same, a small compact fairly conspicuous open cluster, S/L 420. The supposedly fainter was observed in only one of five sweeps by Herschel. Dreyer therefore questioned it as a variable nebula.” ESO also identifies the cluster as NGC 1932 = NGC 1933 but only the latter number should apply to the cluster.

NGC 1649:

The identification of NGC 1649 is disputed.  It may refer to the small cluster [KMHK 22] or more likely NGC 1649 is a duplicate observation of NGC 1652.

John Herschel discovered NGC 1649 = h2660 on 23 Dec 1834 and recorded “F; R; gbM; 30″.”  His position is 9′ S of h2661 = NGC 1652, which he observed on 3 sweeps, but not on the single sweep that NGC 1649 was recorded.  Harold Corwin concludes NGC 1649 is likely a duplicate of NGC 1652 based on the similar descriptions and a possible 10′ digit error in declination.  The Hodge-Wright LMC Atlas states “possibly NGC 1652” (no object is indicated) and ESO equates NGC 1649 = NGC 1652.  NGC 1649 is classified as nonexistent in Mati Morel’s “A Visual Atlas of the LMC”.  Eric Lindsay, in “Some NGC objects in the Large Magellanic Cloud” [1964IrAJ….6..286L], states “Not found. Centered on CPD -69°284. Possibly the faint cluster S/L 8, 13′ south.”

But Jenni Kay disagrees and notes there is a small cluster (ESO 55-031 = KMHK 22) just 2.3′ NNW of JH’s positon for NGC 1649 which may be the correct object.  The visual appearance in a 30-inch is given in my notes.

NGC 1840

NGC 1840 may the asterism of four mag 13.7-14.7 stars within 1.4′ at this position. In addition a couple of mag 15-16 stars were resolved at 394x. Situated in a sparsely populated field.

More likely, though, NGC 1840 is a duplite of NGC 1833.

John Herschel discovered NGC 1840 = h2771 on 3 Nov 1834 and described “F, R, bM, resolvable. Hardly visible through a thick haze. The observations makes the RA 6m 13.5s, but this is impossible from the context [of the sweep]. It *may* be 8m.” In the Cape observations, Herschel gives a position of 5h 7m 13.5s (1830), which is ~3′ too far west, and that position is also used in the GC. In any case, the only nearby object is an asterism of 4 stars.

Eric Lindsay, in the 1964 paper “Some NGC objects in the Large Magellanic Cloud”, comments “There is some confusion about the RA. Dreyer chose the position 5h 6m 13.5′ (1830) instead of 5h 7m 13.5s adopted by Herschel. There is nothing at either position. The object was hardly visible though a thick haze, the observation made the RA 6m which was considered impossible and may even by 8m. At the latter is the small cluster S/L 235.”

In August 2016 Harold Corwin went over the sweep carefully and concluded “Checking this arc, we find two candidate objects: NGC 1833 and SL 249 (at 05 07 35, -70 44.9). The NGC object (= h 2765) is the larger and brighter of the two, and its position is off JH’s by even digits: 1 minute of time, and 1 degree of declination. This makes it likely to also be NGC 1840.”

NGC 1881

SG: A long, curving chain of stars (part of stellar association LH 35) extends to the northeast of the NGC 1874/76/77 HII complex and ends at an easy pair of mag 12 stars (12″ separation) located about 2.5′ NE of the globular NGC 1872. At 260x, faint haze or unresolved stars, ~1′ in diameter, encompasses this pair of stars.

Although there is dim nebulosity generally north and west of the double, John Herschel’s description and sketch refers to an asterism of 5-6 faint stars 2.5′ following the pair of stars. Modern sources are incorrect in identifying NGC 1881 with the pair of mag 12 stars.

John Herschel discovered NGC 1881 = h2810 on 17 Jan 1838 and recorded “vF; follows a double star. An outlier of the arc-formed nebula and cluster [N1874/76/77]. Laid down in drawing Jan. 17, 1838, whence also its place. See Plate III. fig. 6.” There are only a handful of faint stars near JH’s position. See Corwin’s notes and my visual description.

NGC 1884:

=Not found or 3 *’s, Corwin.  =Not Found, Lindsay.

John Herschel discovered NGC 1884 = h2812 on 3 Jan 1837 and noted,”eF, 2′ diameter.”  There is nothing obvious on the DSS at his position (29 tsec east and 2′ south of NGC 1882).  Eric Lindsay reports “not found” in his 1964 paper “Some NGC objects in the Large Magellanic Cloud”.  ESO equates NGC 1884 with NGC 1882.  Since NGC 1882 and 1884 were recorded on the same sweep, this seems unlikely.  If JH made a 10′ error in dec, then NGC 1884 could be a duplicate of NGC 1887 instead, though his size estimate would be significantly too large.  Finally, Harold Corwin notes this number may refer to 3 stars close to JH’s position.

NGC 1899

SG: 30″ (10/15/15 – OzSky): at 303x and 394x; no cluster or nebulous object was in the field at the nominal position, which included three mag 11 stars and the rest mag 13 and fainter. I see nothing that would have caught John Herschel’s attention in the field.

John Herschel discovered NGC 1899 = h2821 on 30 Dec 1836 and reported as “F; R; vgbM; 40″; 3 stars 10′ [approximate] mag precede.”

Eric Lindsay reports “Not found” in his 1964 paper “Some NGC objects in the Large Magellanic Cloud”.  Nevertheless, there appears to be a small very faint star and nebulosity (Henize 120-N 36) on the red DSS2 2′ SE of Herschel’s position. The Hodge-Wright Atlas states “possibly Henize 36”.  Two mag 11 stars and a mag 12.7 star precede LHA 120-N 36, roughly agreeing with “3 stars 10′ m precede.”  See Harold Corwin’s notes for more on this number.

NGC 1911:

NGC 1911 = NGC 1921

John Herschel discovered NGC 1911 = h2826 on 23 Dec 1834 and recorded “F; R; gbM; 30″, among may stars.” He only logged this object on one sweep and there is nothing at his position. Jenni Kay and Harold Corwin suggest NGC 1911 is probably be a duplicate observation of NGC 1920, which was recorded on 7 sweeps but not on the one in which he recorded NGC 1911. JH’s position is 80 sec of RA west of this cluster and his description is a reasonable match.

Eric Lindsay, in his 1964 paper “Some NGC objects in the Large Magellanic Cloud” writes “Not found. This should be WNW of NGC 1920. This is No 2826 in Herschel’s general Catalogue to which there is reference under NGC 1915.” RNGC follows Lindsay and classifies this number as nonexistent. See Corwin’s notes.

NGC 2036

John Herschel discovered NGC 2036 = h2917 on 11 Nov 1836 and recorded “vF; R; gbM; 90″.”  There is nothing at his position, but one degree south is the cluster S-L 587.  Herschel’s added a note to his description that there was likely an error of 1° in the polar distance and clearly this was the case.  Eric Lindsay, in the 1964 paper “Some NGC objects in the Large Magellanic Cloud” (IAJ, 6, 286-289) comments “The Decl. seems to be in error. The object is probably the small cluster S/L 587 at 1° south. Herschel found strong ground to suspect an error of a degree in P.D. which should most likely be 160° and not 159°.”  As this cluster is exactly 1° S of h’s position, the identification is virtually certain.

Also, see historical notes for NGC 2043.  This number may be a duplicate observation with the 48″ Great Melbourne Telescope.

NGC 2043

=NGC 2036?, Jenni Kay. =NF, Lindsay. =ESO 56-SC168, ESO and Corwin.

Pietro Baracchi discovered NGC 2043 on 18 Dec 1884 with the 48-inch f/41 Great Melbourne Telescope and it was included in R. L. Ellery’s “Observations of Southern Nebulae made with the Great Melbourne Telescope 1869 – 1885”. He wrote “preceding H. 1259 [NGC 2058] by 79.5 sec and 4′ 30″ north is a small elongated group of minute stars in very thin nebula..”. There is nothing at his offset from NGC 2058 except very faint stars. ESO identifes ESO 056-168, an extremely faint cluster close to Baracchi’s position, as NGC 2043. But this cluster is probably too faint. Eric Lindsay, in the 1964 paper “Some NGC objects in the Large Magellanic Cloud” (IAJ, 6, 286-289), comments “Not found. Star-rich region but no evidence of clustering. Not listed by Herschel. In the Melbourne Catalogue.”

Harold Corwin suggests NGC 2043 is a N-S string of stars (about 1.7′ length) situated 2.5′ S of Baracchi’s position, which is a good match with his description.

Jenni Kay suggests NGC 2043 was a duplicate observation of NGC 2036, discovered earlier by John Herschel but with a published error in declination of 1 degree (he actually noted that this was a strong possibility). Furthermore, the GC (and later the NGC) carry forward this declination error without any reference to the discrepancy. So, Baracchi would have thought this cluster was a new discovery. This requires he made a 1 min error in RA (NGC 2036 precedes NGC 2058 by 2 min 23 sec of RA, instead of 1 min 20 sec of RA), though the dec would be fairly close.

NGC 2171

John Herschel discovered NGC 2171 = h3016 on 16 Dec 1835 and recorded “eeF; vL; R; glbM; 4′.” There is nothing at this position though ~5′ NW is S-L 809 = KMHK 1571. Eric Lindsay, in his 1964 paper “Some NGC objects in the Large Magellanic Cloud” (IAJ, 6, 286-289), notes “This may be the small object S/L 809, 0.5 min W, 2′ N which may be an unresolved cluster or possibly a galaxy. The size does not agree.” SIMBAD also identifies S-L 809 as NGC 2171. But this tiny cluster is roughly 30″, so it’s not a reasonable match with a 4′ object. The Hodge-Wright Atlas misidentifies a faint star as NGC 2171.

Mati Morel has proposed that h3016 is a star cloud at 05 44 14 -70 40 09, which includes S-L 691 and S-L 692. This requires a very large error in RA (over 15 min of RA). Harold Corwin notes that the sweep order argues against such an error (see his identification notes) and this object appears to be lost.

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