John Herschel discovered NGC 4815 = h3443 on 13 Mar 1834 and recorded "Class VI, p rich, irregular fig, gbM, 3', stars vS, comparatively insulated; has two bright stars 8-9th mag and 9-10th mag." On a second observation he described a "Cluster, R, pS, resolved; irreg; gbM, 3', stars 13..18th mag." Innes was unable to resolve the cluster in 1901 using a 7-inch refractor from the Cape of Good Hope (MN, 62, 469).

300/350mm - 13.1" (2/20/04 - Costa Rica): at 105x, two mag 10 stars are surrounded by a number of very faint stars within 3'. The cluster is superimposed on a fairly bright milky background of unresolved stars. A third mag 10 star is apparently outside the border off the SW edge. At 200x, the unresolved glow is most prominent at the following end and 12-15 mag 13 stars are sprinkled over the backround glow (the cluster was viewed at a very low elevation which probably detracted from the view). This reddened cluster is heavily obscured and is located just within the SE border of the Coalsack and barely over the border into Musca, 1.1 degrees ENE of the bright double star Theta Muscae (5.9/7.7 at 5"). The two brighter mag 10 stars (separated by 1.3') may be foreground stars and not actual cluster members.

Notes by Steve Gottlieb