Dwarf galaxies - the smallest families of stars in the Universe - played a larger role than once believed in star creation. 

The Hubble Space Telescope was used by astronomers to calculate the rate of star production in the tiny galaxies. 

Astronomers have studied relationships between the mass of galaxies and the rates of star formation for over a decade. Most of these studies examined star groupings of medium to large sizes, largely ignoring the role of star production in dwarf galaxies. 

"We already suspected these kinds of galaxies would contribute to the early wave of star formation, but this is the first time we've been able to measure the effect they actually had," Hakim Atek of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, said. 

The Wide Field Camera 3 (WFC3) aboard the orbiting observatory was used to obtain the data on miniscule families of stars.

These tiny galaxies were common between 10 and seven billion years in the past. Some of these are classified as starburst galaxies, which produce stars at a rate much faster than normal. Astronomers were unable to study distant dwarf galaxies until recently, due to their size. However, the WFC3 and accompanying infrared spectrometer made measurements of the collections of stars possible. 

Examination of dwarf galaxies can help astronomers better understand star formation, as well as how galaxies few three-and-a-half to six billion years after the big bang. 

"These galaxies are forming stars so quickly they could actually double their entire mass of stars in only 150 million years -  an incredibly short astronomical timescale," Jean-Paul Kneib from EPFL, said. 

Most galaxies take between one and three billion years to experience similar growth. They often merge with other collections of stars, which combines the amount of gas in each system. This can gravitationally collapse, driving the formation of additional stars. 

Astronomers believe starburst galaxies may be fueled by these massive mergers, leading to their prolific output. Other theories say gravitation pulls from other galaxies or explosions of massive supernovas could be driving stellar formation in starburst formations. 

As stars get old and die, they pass stellar material back into surrounding space. 

A typical dwarf galaxy contains a few billion stars, compared to an estimated 200-400 billion in our own Milky Way. The local group, which contains our own galaxy, is home to many dwarf galaxies. These small groups often orbit larger galaxies, and around 20 circle around our personal family of stars. 

Study of Hubble Space Telescope data revealing how stars are produced in dwarf galaxies was detailed in The Astrophysical Journal.