One of the sky’s standout objects is the Tarantula Nebula, also known as the True Lovers’ Knot, Caldwell 103, and 30 Doradus. At the center of this HII region (a cloud of ionized hydrogen) is the massive open cluster NGC 2070. It’s the central group of ultrahot stars in this cluster that produces the ultraviolet radiation that makes the nebula glow.
It’s too bad that most amateur astronomers living in the Northern Hemisphere haven’t observed the Tarantula Nebula. Although it lies 160,000 light-years away in the Large Magellanic Cloud (see #80), this object looks great through any telescope. Sporting a true diameter of more than 1,800 light-years, the Tarantula would appear some 25° across if it were as close as the Orion Nebula (M42; see #19). At that distance, its overall brightness would top that of Venus, and it would even cast shadows.
NGC 2070 is a young open cluster some astronomers categorize as a super star cluster. Such objects are brighter and more massive than the run-of-the-mill open clusters we see elsewhere. But it’s really the central 16 light-year-wide region of NGC 2070 that stands out. Listed in the Radcliffe Observatory Magellanic Clouds Catalogue as R136, this is an amazing starburst region. Many of its 72 stars are among the most massive, brightest, and hottest stars known.
R136 is easy to spot through a 4-inch scope as a 1′-wide region. The same instrument will reveal a few gaseous loops and filaments in the nebula. The longest starts at the cluster’s center and stretches 7′ to the south. Then it curves east and finally northward. Look to the east of R136 for two easy-to-see dark bays.
Make sure to explore Astronomy’s full list of 101 cosmic objects you must see. New entries will be added each week throughout 2022.
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