Just in time for the Hubble Telescope’s 26th birthday on Sunday, April 24, the orbital telescope has snapped an amazing sight: a stunning photo of the aptly named Bubble Nebula that drifts about 8,000 light years away from Earth in the Cassiopeia Constellation.
The Bubble Nebula was first discovered in 1787 by William Herschel, though it’s safe to say that the 18th-century astronomer didn’t get nearly as good a glimpse at it as the new images coming from the Hubble. Also known as NGC 7635, the Bubble Nebula is made up of a massive cloud of gas and dust about 10 light years across that swirls around a star that is 20 times larger than our own sun. While the Hubble has snapped shots of the nebula in the past, this is the first time that researchers have stitched together several different images to get a look at the brilliant Bubble in its entirety, Rachel Feltman reports for the Washington Post.
“If you compare [the new picture] to the earlier images you would see some very, very small changes,” European Space Agency researcher Mathias Jäger tells Nicola Davis for the Guardian. “Nothing spectacular for the lay eye, but for astronomers it is enough to see how the gas behaves inside the bubble.”
Putting the Bubble Nebula into a larger perspective showcases just how intriguing it is. The complete image not only highlights the nebula’s size but also its oddly symmetrical shape. According to the Hubble researchers, the emission nebula is still expanding due to the pressure from the stellar winds given off by the star at its heart, known as SAO 20575. Considering that the nebula is nearly spherical in shape, it would make sense if the star was located at its center. However, SAO 20575 is actually off to one side of the nebula – a fact that still has scientists scratching their heads, Tariq Malik writes for Space.com.
“Astronomers are still discussing why this is the case and how the perfectly round bubble is created nonetheless,” write the Hubble researchers in a statement.
While the Bubble Nebula is still expanding at a rapid rate of about 62,000 miles per hour, at some point in the distant future the cloud of gas and dust will grind to a halt.
“The cloud gets denser and denser as you get to closer to its center, so at some point the cloud will be too dense for the weaker and weaker solar wind to push even further,” Jäger tells Davis.
The Hubble was first launched into orbit aboard the space shuttle Discovery on April 24, 1990. The satellite has had an amazing, long career, delivering some of the most gorgeous views of far-off objects in the universe to earth. But in 2018, its successor, the James Webb Telescope, is scheduled to be launched into orbit, Feltman writes. With state-of-the-art equipment, the new orbital telescope will give astronomers an even more detailed look at distant stars. But even with James Webb Telescope's potential, it will have quite a career to live up to.