Face-on starburst spiral galaxy MCG+07-33-027 lies 300 million light-years from Earth in the constellation of Hercules. Click the image for a full-size version. Image credit: ESA/Hubble & NASA and N. Grogin (STScI).This image was taken by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), and shows a starburst galaxy named MCG+07-33-027. This galaxy lies some 300 million light-years away from us, and is currently experiencing an extraordinarily high rate of star formation — a starburst. Normal galaxies produce only a couple of new stars per year, but starburst galaxies can produce a hundred times more than that! As MCG+07-33-027 is seen face-on, the galaxy’s spiral arms and the bright star-forming regions within them are clearly visible and easy for astronomers to study.
In order to form newborn stars, the parent galaxy has to hold a large reservoir of gas, which is slowly depleted to spawn stars over time. For galaxies in a state of starburst, this intense period of star formation has to be triggered somehow — often this happens due to a collision with another galaxy. MCG+07-33-027, however, is special; while many galaxies are located within a large cluster of galaxies, MCG+07-33-027 is a field galaxy, which means it is rather isolated. Thus, the triggering of the starburst was most likely not due to a collision with a neighbouring or passing galaxy and astronomers are still speculating about the cause.
The Atacama Large Millimetre/submillimetre Array has produced a spectacularly detailed image of a distant galaxy known as SDP.81 that is being gravitationally lensed. The image shows a magnified view of the galaxy’s star-forming regions, the likes of which have never been seen before at this level of detail in a galaxy so remote.
In this NASA/ESA Hubble Space Telescope image we see the central Wolf-Rayet star known as Hen 2-427 — more commonly known as WR 124 — surrounded by the nebula M1-67. Both objects are found in the constellation of Sagitta some 15,000 light-years away. The hot clumps of gas ejected by the star into space are travelling at over 150,000 kilometres per hour.
