Last updated March 28, 2018 at 2:01 pm
The Hubble Space Telescope caught this incredible rose made of galaxies
To celebrate the 21st anniversary of the Hubble Space Telescope‘s deployment into space in 2011, astronomers pointed Hubble’s eye at an especially photogenic pair of interacting galaxies called Arp 273.
The larger of the spiral galaxies, known as UGC 1810, has a disk that is distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. It is thought that the smaller galaxy has actually passed through the larger one.
This image is a composite of Hubble Wide Field Camera 3 data, with three separate filters that allow a broad range of wavelengths covering the ultraviolet, blue, and red portions of the spectrum.
Arp 273 lies in the constellation Andromeda and is roughly 300 million light-years away from Earth. The image shows a tenuous tidal bridge of material between the two galaxies that are separated from each other by tens of thousands of light-years.
A series of uncommon spiral patterns in the large galaxy is a tell-tale sign of interaction. The large, outer arm appears partially as a ring, a feature seen when interacting galaxies actually pass through one another. This suggests that the smaller companion actually dived deep, but off-center, through UGC 1810. The inner set of spiral arms is highly warped out of the plane, with one of the arms going behind the bulge and coming back out the other side. How these two spiral patterns connect is still not precisely known.
A possible mini-spiral may be visible in the spiral arms of UGC 1810 to the upper right. It is noticeable how the outermost spiral arm changes character as it passes this third galaxy, from smooth with lots of old stars (reddish in color) on one side to clumpy and extremely blue on the other. The fairly regular spacing of the blue star-forming knots fits with what is seen in the spiral arms of other galaxies and is predictable based on instabilities in the gas contained within the arm.
The larger galaxy in the UGC 1810 – UGC 1813 pair has a mass that is about five times that of the smaller galaxy. In unequal pairs such as this, the relatively rapid passage of a companion galaxy produces the lopsided or asymmetric structure in the main spiral. Also in such encounters, the starburst activity typically begins in the minor galaxies earlier than in the major galaxies. These effects could be because the smaller galaxies have consumed less of the gas present in their nuclei, from which new stars are born.
Hubble changed our view of the universe
Hubble was launched on 24 April 1990, aboard Discovery’s STS-31 mission.
“Hubble has profoundly changed our view of the universe, allowing us to see deep into the past while opening our eyes to the majesty and wonders around us,” former NASA Administrator Charles Bolden said. “I was privileged to pilot space shuttle Discovery as it deployed Hubble. After all this time, new Hubble images still inspire awe and are a testament to the extraordinary work of the many people behind the world’s most famous observatory.”
Hubble discoveries revolutionized nearly all areas of current astronomical research from planetary science to cosmology.
“Hubble is America’s gift to the world,” Senator Barbara Mikulski of Maryland said. “Its jaw-dropping images have rewritten the textbooks and inspired generations of schoolchildren to study math and science. It has been documenting the history of our universe for 21 years. Thanks to the daring of our brave astronauts, a successful servicing mission in 2009 gave Hubble new life. I look forward to Hubble’s amazing images and inspiring discoveries for years to come.”
Coordinates of the image
Position (RA): 2 21 30.37
Position (Dec): 39° 21′ 51.96
Field of view: 2.63 x 2.66 arcminutes
Orientation: North is 33.8° left of vertical