S-L 158 = KMHK 397

04 59 14.4 -70 15 23; Men
V = 11.9

30″ (11/6/10 – Coonabarabran, 264x): bright, compact knot (cluster), round, 20″ diameter, surprisingly high surface brightness. Located 5.4′ S of NGC 1791.

Notes: Shapley-Lindsay: 35″ diameter. “Condensed, round.”

NGC 1815 = ESO 056-049 = S-L 189

05 02 27 -70 37 18; Men
V = 12.4; Size 1.2′

30″ (11/6/10 – Coonabarabran, 264x): fairly bright, small, round. The very bright core partially resolves into a couple of knots, 25″ diameter. A single faint star is resolved at the north edge. A mag 12.5 star lies 1′ SSE and several mag 11-12 stars are in the field. Located 9′ due E of mag 7.6 HD 32956.

Notes: John Herschel discovered NGC 1815 = h2753 on 24 Nov 1834 with description, “pF, vS, R, very little brighter middle, among many stars.” His position is accurate.

NGC 1813 = ESO 056-050 = S-L 190 = LH 18

05 02 40 -70 19 06; Men
V = 12.8; Size 0.8′

30″ (11/6/10 – Coonabarabran, 264x): first in a string of three clusters with NGC 1823 4′ ESE and S-L 200 7′ SE (within stellar association LH 18). Appears as an irregular 45″ glow with a single brighter mag 14 star on the S end and three fainter stars aligned E-W resolved on the N side.

Notes: John Herschel discovered NGC 1813 = h2752 on 16 Dec 1835. His single observation reads, “vF; S; R; resolvable.” His position is just 0.1 minute of RA preceding the cluster’s center.

NGC 1823 = ESO 056-051 = S-L 198 = LH 18

05 03 25 -70 20 06; Men
V = 12.1; Size 0.9′

30″ (11/6/10 – Coonabarabran, 264x): fairly bright irregular cluster with 8 or 9 resolved stars within 45″. Five of the resolved stars are collinear on the W side and oriented ~N-S. NGC 1823 is the second of three clusters with NGC 1813 4′ WNW and S-L 200 4′ SSE. The surrounding field is filled with a scattering of mag 12-13 stars and a large number of fainter stars (this is the stellar association LH 18). S-L 200 is the largest of the three clusters, 1.2’x0.6′ extended N-S, with several stars resolved over a hazy background or emission glow and a detached group of 4 stars off the south end.

Notes: John Herschel discovered NGC 1823 = h2758 on 12 Nov 1836 and described “The most compressed part of a pF; L; branching cluster of stars 12…15m.” His position is on the SE side of the cluster. Hodge and Lucke (1970) note this open cluster lies within the LMC O-association No. 18; the brightest star in the cluster is 13.9 mag.

S-L 200 = KMHK 492

05 03 45 -70 24 00; Men
V = 12.8; Size 1.3′

30″ (11/6/10 – Coonabarabran, 264x): largest of three clusters with NGC 1823 4′ NNW and NGC 1813 7′ NW. Appears 1.2’x0.6′, extended N-S. Several stars are resolved over a hazy background or emission glow. A detached group of 4 stars is off the S end. Situated on the S side of stellar association LH 18.

Notes: Shapley-Lindsay: 55″ diameter. “Few stars, possibly field irregularity.”

NGC 1833 = LMC-N190 = ESO 056-55 = S-L 206 = LH 24

05 04 22 -70 43 54; Men
V = 11.7; Size 2′

25″ (10/10/15 – OzSky): at 318x; fairly large nebulous patch 1.5′ diameter with a mag 13.4 star near the center and a half-dozen additional stars resolved (part of stellar association LH 24). The nebulosity showed a fair response using the NPB filter with a brighter piece on the NE side and a 2′ irregular shape. NGC 1833 is located at the S end of the huge NGC 1845 stellar association/Star Cloud (LH 26), and many brighter stars over a rich, glowing background extend a full 20′ NNE! Mag 9.5 HD 269028 lies 3.2′ NNW. NGC 1837 lies 3′ ENE.

Notes: John Herschel discovered NGC 1833 = h2765 on 12 Nov 1836 and recorded “vF; pL; runs into and forms the first mass of a series of clustering groups.” His position is accurate.

NGC 1837 = ESO 056-059 = S-L 217 = LH 24

05 04 56 -70 42 54; Men
V = 10.6; Size 1.3′

25″ (10/10/15 – OzSky): at 318x; this cluster is mainly a very elongated N-S string of stars with some unresolved haze. There was no filter response. A few brighter mag 12.5-13 stars are involved with a total of a dozen in the 1.2′ string. NGC 1837 forms a 3′ pair with NGC 1833 to the WSW (part of association LH 24). Another star cloud extends to the N with several mag 12 stars, along with many faint stars in the wider field. This magnificent star cloud (LH 26) is rich in bright and faint stars.

Notes: John Herschel discovered NGC 1837 = h2769 on 3 Nov 1834. He observed this cluster on two sweeps and recorded it as “The last of three clustering groups (hazy)” and “the most condensed part of a large rich cluster of scattered stars which more than fills field.” Archinal notes the brightest star is at 05 04 56.8 -70 42 57, close to Herschel’s second position. It is not clear what other two objects Herschel was referring to in his first sweep as only NGC 1833 is in the same field, though the star cloud (stellar association LH 24) containing these clusters extends to the NE.

NGC 1845 = ESO 056-065 = S-L 232 = LH 26

05 06 22 -70 35 24; Men
V = 10.2; Size 20′

25″ (10/10/15 – OzSky): at 318x; this very large star cloud (LH 26) completely fills the 19′ field. The small open cluster S-L 232, which is often taken as NGC 1845, is at the NE end. It appeared as a moderately bright, nebulous patch, roundish, 30″ diameter, unresolved. A mag 11.2 star is 0.9′ SW. The star cloud generally trends NE to SW from S-L 232, stretching ~20’x10′, and includes the open cluster NGC 1833 and 1837 at the SW end. It contains a stunning mix of bright stars (a few mag 9.5 stars are Milky Way stars), numerous mag 12-13 stars and faint stars over the glowing LMC background haze of myriad unresolved stars.

Notes: John Herschel discovered NGC 1845 = h2770 on 24 Nov 1834 and simply noted the position was “the general middle of the same cluster [field containing NGC 1837 = h2769].” On a second sweep he gave the more detailed description: “a star 9m the second in magnitude and near the centre of clustering groups which run together and form a cluster which fills the whole field. vl compressed middle; stars 11…16m.” His two positions refer to different objects: probably the small cluster S-L 232 to the NE of HD 269070 and the much larger star cloud itself (LH 26 association). Uranometria 2000 atlas misclassifies this object as a bright nebula. The Hodge-Wright LMC Atlas identifies S-L 232 as NGC 1845.

S-L 232 = KMHK 545

05 06 22 -70 28 48; Men
V = 12.7; Size 1.2′

25″ (10/10/15 – OzSky): at 318x; moderately bright nebulous patch (cluster), roundish, 30″ diameter, unresolved. HD 269074, a mag 11.2 OB star and part of the small cluster BSDL 635, is 0.9′ SW. S-L 232 is located at the NE edge of the LH 26 star cloud, which primarily includes NGC 1845.

Notes: Shapley-Lindsay: 70″ diameter. “NGC 1845, condensation in rich field.”