Christmas arrived a little early this year for astronomers who study the depths of the universe.
NASA released an image of the Christmas Tree galaxy cluster, a glittering cluster of galaxies 4.3 billion light-years from Earth, last month using data from the James Webb Space Telescope. Last Monday, First Lady Jill Biden presented a snapshot of Cassiopeia A, the remains of a star that exploded 340 years ago, as part of the 2019 White House calendar.
These and other photographs continue an astronomical tradition of linking the holiday season with cosmic occurrences occurring light years away from Earth. Some of these observations, however, contain scientific miracles.
The discovery by astronomers of 14 stars that flicker for days or months - like the lights on a Christmas tree - lies at the centre of the "Christmas Tree" galaxy cluster.
"Seeing an individual star in a distant galaxy is a big event," said Haojing Yan, the study's lead author and an astronomer at the University of Missouri. "Almost like a miracle," he continued.
It's been a rare joy to discover distant stars. "With the Web, it became routine," said Roger Windhorst, an Arizona State University astronomer who was involved in the finding.
The findings are made possible via gravitational lensing, an effect in which the gravity of cosmic structures distorts and magnifies the light of background objects, allowing astronomers to see them. The stars twinkle as a result of these "lenses" going in and out.
Windhorst observes that the Earth and Sun are nearly as old as the light emitted by this flickering cluster, which was already 9 billion years old when the light was emitted. Data on such distant stars aids astronomers in comparing the composition of ancient galaxy clusters to those closer to us, as well as how our solar system fits into what Windhorst refers to as the cosmic circle of life.
Cassiopeia A is substantially closer to Earth than the Christmas Tree galaxy cluster. Scientists have long researched starbursts and other phenomena in order to better comprehend their role in cosmic evolution.
"They help galaxies grow," says Dani Milisavljevic, an astronomer at Purdue University who studies Cassiopeia A. Supernova remnants create materials required for life, such as "the oxygen we breathe, the iron in our blood, and the calcium in our bones," he adds.
Cassiopeia A, located 11,000 light-years from Earth, has been detected in visible, X-ray, and infrared wavelengths by several satellite telescopes. However, Webb's new infrared vision improves visibility.
NASA released an image of the supernova remnant taken with the telescope's mid-infrared instrument in April. The most recent image was captured with Webb's near-infrared camera, which captures gas, dust, and molecules that emit at higher temperatures.
The pink and orange structures, encased in misty substance against a backdrop of glittering stars, like a tree branch ornament.
Long before Webb, astronomers frequently discovered Christmas spirit in space.
In 2008, the European Southern Observatory released an image of a star cluster that resembles sparkly baubles for a Christmas tree. The cluster is pictured by Chile's La Silla Observatory within purple clouds of gas. The Cone Nebula, a star-forming region roughly 2,500 light-years from Earth, is visible near the bottom of the image.
The Hubble Space Telescope of NASA also spreads holiday pleasure. In 2010, the space agency released an image of a crimson bubble floating amid the stars that resembled a glittering Christmas decoration.
This bubble is made of gas that a supernova spewed at millions of kilometres per hour. Astronomers believe the explosion was triggered by a white dwarf (the core of a dying star) that ingested debris from a neighbouring star.
A year later, Hubble captured an incredible image of a cosmic snow angel: a star in our galaxy encircled by blue 'wings' of heated gas.
It appears that even space wishes us a Merry Christmas./BGNES
