NGC 1871 = LMC-N30B = ESO 056-085 = S-L 325 = LH 38

05 13 52.0 -67 27 08; Dor
V = 10.1

30″ (10/12/15 – OzSky): this nebulous cluster contains 5 or 6 bright stars (mag 11.5-13) and 10 stars total (OB association LH 38), 2′ diameter, elongated E-W. A very small nonstellar knot (N30B) is near the center; a mag 11.8 blue supergiant (Henize S22 = HD 34664, LBV candidate) is just 25″ N and a mag 11.4 star (HD 269195) is at the E end. Nebulosity encases the stars and is moderately enhanced with a NPB filter. NGC 1871 is located at the SE end of a 15′ star cloud (includes LH 32/34/36/37/38) with NGC 1869 = S-L 326 4.6′ N and NGC 1873 7′ N.

13.1″ (2/20/04 – Costa Rica): at 105x, this is a small group of stars in the LMC, 4 stars are resolved in nebulosity. NGC 1873 lies 7′ N and NGC 1864 is 12′ SW.

Notes: James Dunlop probably discovered NGC 1871 = D 210 = D 182 = h2800 on 24 Sep 1826. He recorded D 210 as “a small round nebula, rather faint. This is the preceding in a line of nebulae and small stars, with a star of the 7th magnitude [probably mag 4.8 Theta Doradus] at the north extremity.” Although NGC 1871 is not “preceding in a line”, it lies at the south end of a line with NGC 1869 and 1873, extending towards Theta Doradus. Dunlop’s D 182, found on 27 Sep, also refers to these clusters: “a bright star [Theta Dor] is at the north extremity of a branched cluster of very small stars of mixed small mag or – with several small faint nebulae in strong nebulosity common to all.” This number is from a drift in which he misidentified the reference star (Theta Dor) and his published position is 2° to the SE.

John Herschel rediscovered NGC 1871 on 2 Nov 1834 (sweep 508) and described “a poor cluster; the southern of three (with NGC 1869 and 1873) of four.” On 2 Jan 1837 (sweep 760) he called it “the second of a series of clusters which extend northwards as far as [Theta Doradus].” His mean position is accurate.

NGC 1869 = LMC-N30A = ESO 085-55 = S-L 326 = LH 37

05 13 52.7 -67 22 41; Dor
V = 10.5; Size 14′

30″ (10/12/15 – OzSky): S-L 326 = LH 37 (middle of three OB associations within a large star cloud) consists of a mag 11.5 star, along with 5 other fairly bright stars and a number of faint stars (12-15 total resolved). The cluster is encased in an irregular HII glow with a brighter patch (N30A) to the SE of the mag 11.5 star. The glow is moderately enhanced with the NPB filter, which reveals nebulosity extending off the cluster to the west. HD 34632 = Brey 17, is a mag 13.1 Wolf-Rayet star (binary) on the west side of the cluster.

NGC 1873 lies 3′ N and NGC 1871 is 4.5′ S. All three clusters appear as local enhancements anchored by bright stars and lie within a striking star cloud (large association of blue supergiants including LH 32/34/36/37/38). A rich background glow of unresolved stars extends W and N.

13.1″ (2/20/04 – Costa Rica): fairly faint, hazy glow (= S-L 326) around a mag 10.5 star (HD 269183) with a couple of mag 12 stars close west. NGC 1873 lies 2.7′ N with 1871 4.4′ S. Located 11.5′ S of mag 4.9 Theta Doradus. Shapley used NGC 1869 as the center of “Constellation” IV, a 33’x33′ association of blue and red supergiants.

Notes: James Dunlop probably discovered NGC 1869 = D 210 = D 182 on 24 Sep 1826. His description of D 210 reads “a small round nebula, rather faint. This is the preceding in a line of nebulae and small stars, with a star of the 7th magnitude at the north extremity.” Dunlop’s sketch (figure 7) appears to support D 210 = NGC 1871 (or part of the “line”), with a small nebula at the opposite end of a curved chain extending to a star (Theta Doradus) at the opposite end. His published position is 3.4′ ESE of S-L 326 in the center of the association (the “point taken” by Herschel). Dunlop’s D 182, found on 27 Sep, also refers to these clusters: “a bright star [Theta Dor] is at the north extremity of a branched cluster of very small stars of mixed small mag or – with several small faint nebulae in strong nebulosity common to all.” This number is from a drift in which he misidentified the reference star (Theta Dor) so his positions are systematically offset.

John Herschel discovered NGC 1869 = h2798 on 30 Jan 1835 (sweep 658) and described a “cluster of 7th class; a fine L cluster of scattered stars which fills field. The point taken is the middle of 3 groups [including NGC 1871 and 1873] in the most condensed part.”

NGC 2000, ESO and Morel’s Visual Atlas of the LMC all identify NGC 1869 with S-L 326, a small cluster flanked by NGC 1871 to the south and NGC 1873 to the north of Herschel’s position. This is the object described by Herschel on his second sweep. But Jenni Kay states, “I am confident the small cluster centrally positioned between NGC 1871 and NGC 1873, being 2.5′ in size is not Herschel’s cluster. The whole star group is attractive enough to warrant it’s own designation. …the small OC was used to measure a position only for the whole group which is the true NGC 1869 cluster.” Based on his two sweeps, NGC 1869 refers BOTH to the small cluster and to the star cloud (Lucke-Hodge associations 36/37/38 as well as 34/32).

NGC 1873 = ESO 085-054 = S-L 324 = LH 36

05 13 55.8 -67 20 00; Dor
V = 10.4

30″ (10/12/15 – OzSky): fairly bright, large resolved cluster, 2.5′ diameter. Includes a bright mag 11.6 star and 20 or more mag 13 and fainter stars over unresolved haze and nebulosity. Moderate contrast gain with NPB filter. Connected to S-L 326 (see NGC 1869) just 2.8′ S and NGC 1871 7.5′ SSW. The three star groups are embedded in a 15′ star cloud (including associations LH 32/34/36/37/38). Faint stars and unresolved haze extends to the west and north as well as a several brighter mag 11.5-12.5 stars 4′ to 6′ W. This excellent region is situated 9′ S of mag 4.8 Theta Doradus.

13.1″ (2/20/04 – Costa Rica): very faint, 4 stars resolved over haze, 1.0′ diameter. Located 9′ S of mag 4.9 Theta Doradus in a series of small clusters including NGC 1871 7′ S and a small group just 3′ S surrounding a mag 10 star that John Herschel gave as the center for NGC 1869.

Notes: James Dunlop probably discovered NGC 1873 = D 210 = D 182 on 24 Sep 1826. His description of D 210 reads “a small round nebula, rather faint. This is the preceding in a line of nebulae and small stars, with a star of the 7th magnitude at the north extremity.” Dunlop’s sketch shows a curved chain of stars and nebulae extending south of a bright star (Theta Doradus). Dunlop’s D 182, found on 27 Sep, also refers to these clusters: “a bright star [Theta Dor] is at the north extremity of a branched cluster of very small stars of mixed small mag or – with several small faint nebulae in strong nebulosity common to all.” This number is from a drift in which he misidentified the reference star (Theta Dor) so his positions are systematically offset.

John Herschel independently discovered NGC 1873 = h2801 on 2 Jan 1837 (sweep 760) and described it as “the third [with NGC 1871 and 1869] of a series of clusters extending to B 922.” His position is accurate.

NGC 1895 = LMC-N33 = ESO 085-62

05 16 52 -67 19 50; Dor
V = 12.9; Size 0.8′

30″ (10/12/15 – OzSky): very bright, irregular HII region, ~45″ diameter, enhanced with NPB filter at 152x. Three mag 14.5-15 stars are involved with the glow, one centrally. A mag 12 star is 1.7′ NNW. NGC 1897 lies 8′ SSE and the NGC 1873 complex (along with NGC 1869 and 1871) is 16′ W.

Notes: John Herschel discovered NGC 1895 = h2817 on 2 Nov 1834 and recorded “pF; pL; R; gradually little brighter middle; 40″.” On later sweeps he estimated the size as 70″ and 80″.