This year, the beloved Hubble Space Telescope turned 30. Launched in 1990, it has been instrumental in helping us understand the expansion of the universe and has allowed us to peer out at objects far beyond our solar system.
Now, NASA has updated its Hubble Caldwell catalog, a collection of some of the most beautiful images Hubble has captured throughout the years. The Caldwell catalog project, which began in 1995, was a list originally compiled by astronomer Sir Patrick Caldwell-Moore as an addition to the traditional Messier catalog which lists astronomical objects that can be seen in the sky. The Caldwell catalog contains 109 objects including galaxies, nebulae, and star clusters which are visible to amateur astronomers.
For astronomers who want to refer to highly detailed images of the objects they’re observing, or simply for those who love to enjoy stunning images of space, the Hubble Caldwell catalog shows all of these objects in exquisite detail, as well as a map of where in the night sky each is located.
Hubble gets festive with a string of cosmic Christmas lights
Researchers using the Hubble Space Telescope are getting into the festive spirit with a holiday image showing a dwarf irregular galaxy called UGC 8091. Located 7 million light-years away in the constellation of Virgo, this region is a hotbed of star formation, with bright young stars illuminating the gas around them to create a sparkling mass reminiscent of Christmas lights.
It is designated an irregular galaxy because of its nonuniform shape, and a dwarf galaxy because of its small size. Unlike spiral galaxies, such as our Milky Way, or elliptical galaxies, which are smooth and have a elliptical shape, irregular galaxies can come in a variety of shapes. Often, these galaxies have been pulled into odd shapes due to gravitational forces, such as when two galaxies come close to each other and interact.
Hubble captures a formation of galaxies neatly lined up
Sometimes, Hubble or other telescopes will capture two or more galaxies that are in the process of merging -- called interacting galaxies. These huge collisions can warp one or both of the galaxies, twisting them into strange shapes. The results of such collisions can be catastrophic, with one of the galaxies being destroyed. Or they can be creative, with one larger galaxy being formed from the two merging galaxies.
However, sometimes galaxies that appear very close in images are not actually interacting. Sometimes, they merely appear to be close when seen from Earth, but they can actually be thousands of light-years apart. That's the case with a previous Hubble image showing two overlapping galaxies.
Hubble Space Telescope is back up and running following gyro problem
The Hubble Space Telescope is back to full operations after spending several weeks in safe mode due to a problem with one of its components. The telescope first experienced issues with one of its gyros on November 19, and was in and out of safe mode several times in the following days. It has remained in safe mode since November 23, but came back online on Friday, December 8.
The problem was caused by one of the telescope's three operational gyros, which are devices that help to point the telescope in the right direction. Although it would have been possible to operate the telescope with just one of these, that would have resulted in lost observing time as it would take longer to move the telescope to a new target between observations. With all three gyros now back in use, the telescope has returned to science operations.