"Imagine walking into a room and all you have are old people, and then you want to figure out how did they get to be old," said Varoujan Gorjian, one of the researchers who worked on the project.
The new findings are like discovering two kids running around in that room, said Gorjian, who works at NASAs Jet Propulsion Laboratory. The announcement came at the annual meeting of the American Astronomical Society in Atlanta, Georgia.
The observations will help fill in the gaps in what we know about the evolution of these globular clusters, he said.
The first of these so-called proto-globular clusters was found in NGC 5253, a dwarf galaxy some 12 million light-years away in the direction of the constellation Centaurus. (A light-year is 5.88 trillion miles.)
NGC 5253 is the orbiting companion of the much better-known M 83 galaxy, but the dwarf is "where all the action is," said Sara Beck, an astronomer at Tel Aviv University, who helped find one of the two new clusters.
Beck had been examining NGC 5253, and she found something odd about the objects infrared and radio emissions.
Seventy percent of all the infrared emissions and at least one-third of the radio emissions, of the entire galaxy come from one small point that isnt visible in optical-light images. (See accompanying images). Its about three light-years by six light-years in area.
In all its characteristics, the area looks like a star-forming region where dense gas is heated and ionized by hot young stars, Beck said. "But there are a lot of young stars in this," she said.
The region is about 100 times denser than the small star-forming regions in the Milky Way, Beck said.
To account for the amount of energy being emitted would require several thousand of the hottest and most massive stars known.
If those stars formed along with smaller, cooler stars, as is typical in the universe, Beck calculates the region holds about 100,000 stars with a total mass about a million times that of the sun. A similar 3-light-year by 6-light-year volume around our own sun has the equivalent of two solar masses worth of stars, she said.
"This has a density, size, and stellar population that might someday be a globular cluster, but it is incredibly young," Beck said.
"We calculate that it cannot keep that density for more than a million years, and we also calculate the kind of stars we think we see as being less than a million years old mere infancy to an astronomer."
The key that seems to show the stars are so young is the fact that they are shrouded by gas and dust that blocks and scatters their visible light, said Jean Turner, a professor of physics and astronomy at the University of California at Los Angeles, who worked with Beck.
"Once stars form, they are remarkably destructive, and they will either burn up or blow away the natal gas cloud in very short order," Turner said.
"Until now we have never observed a super-star cluster or a cluster the size of a globular cluster actually forming at a stage early enough that it is still surrounded by its birth cloud. But now we think we have."
Not only that. There appear to be two.
The second proposed example of a newborn globular cluster is found in a galaxy called Heinze 2-10, which lies 30 million light-years away in the direction of the southern constellation Pixes.
University of Wisconsin-Madison astronomer Chip Kobulnicky and Kelsey Johnson of the University of Colorado used the Very Large Array of radio telescopes in northern New Mexico to reveal details in Heinze not observable in visible light. (See accompanying image.)
They found extremely dense, hot nebulas that like the areas in NGC 5253 they think can only be energetic young globular clusters, each containing several hundred of the most massive type of stars.
The astronomers on both teams said these discoveries provide a window to the ancient universe, to a time when globular clusters were probably forming at a much more rapid pace.
In the current universe the majority of star formation does not occur in globular clusters, but that may not have always been so.
A commonly accepted theory reasons that the early universe was a much more energetic, rambunctious place and perhaps the majority of star formation occurred in young globular clusters.
During the past several billion years, many of the clusters could have broken apart, scattering their stars throughout the universe, and some such as the old ones we see in the Milky Way survived.
The two infant clusters can only help scientist build a better understanding of stellar and galactic evolution, Johnson said.
"What were seeing really is an explanation of what happened in the early universe," she said.
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