NGC 2100

Historical observations

John Herschel (1847) Cape Observations

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "the cluster S.f. the great looped nebula." On a second occassion he called it "a bright small cluster of distinct stars (thick haze)." His third observation was recorded as "globular, bright, round, 3', all resolved into stars 13..16th mag." He next recorded it as "globular cluster, irregularly round, psmbM, 2'." The final record reads: "bright, small, much compressed, not much brighter to the middle; irregular oval, 3', stars distinct 13th mag." He notes that it may be the same as Dunlop 147, 151 or 154.

Published comments

Bailey, S.I. (1908)

"globular cluster; fairly condensed; apparently nebulous; LMC."

Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.

Shapley & Wilson (1925)

Harvard Circular 271, "The Magellanic Clouds, IV."

(p.5/6) "Of the scores of open clusters in the Large Magellanic Cloud, six of the brightest and most compact have been measured for the present survey. NGC 1856 may be a globular cluster."

NGC 1854 (1855), apparent magnitude 7.1

NGC 1856, apparent magnitude 7.0

NGC 1986, apparent magnitude 8.0

NGC 2058, apparent magnitude 7.7

NGC 2065, apparent magnitude 7.8

NGC 2100, apparent magnitude 6.3

Hodge, P.W. & Lucke, P.B. (1970)

This object in the LMC lies within the LMC O-association No. 111; the brightest star in the cluster is 11.7 mag. (Hodge, P.W. and Lucke, P.B., Astronomical Journal, Vol 75, No. 8, 1970, p933-937)

Shapley & Lindsay (1963)

("A Catalogue of Clusters in the Large Magellanic Cloud", Irish Astronomical Journal, Vol. 6, 1963) give a diameter of 2.3' and remark "bright condensed centre, outer well resolved."

Van den Bergh and Hagen (1968)

("UBV photometry of star clusters in the Magellanic Clouds", Astronomical Journal, Vol. 73, 1968) find that the integrated V magnitude through a 60'' diaphragm is 9.6. They classify it as an open cluster.

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 9.5 mag cluster+nebulosity in the LMC.

Press releases

ESO PR 1033: "New Tarantula image".

Modern observations

ASV Journal (1971)

Vol 24 No 3 June 1971: "small, compact cluster in 4-inch 64x."

Brian Skiff

15cm - br well res cl SE of Tarantula. 1'.5 diam w/30 *s res plus many more too

crowded to deal with at 140x. mod-strong concen to clumpy cen. BS,

18Nov1993, LCO.

Contemporary observations

Auke Slotegraaf

2009 February 27/28

Sutherland (Huis Lana)

"Bertha" 12-inch f/4.8 Dobsonian (EP: 32mm, 25mm, 10mm, 6.3mm Plossls, 2x Barlow, 32mm Erfle)

Conditions: Clear, dark.

Bright knot of stars. Prominent in 21' field of view. Curious appearance: looks like a small globular cluster overlaid with a coarse open cluster. Diameter 2.3 arcminutes. I see what looks like a small globular cluster, growing much brighter to the middle. Widely scattered over and around it is a coarse open cluster of 30 vF and vvF stars. Lies close north-east of Tarantula. (MSA 495)