Image credit: Caldwell 78 (NGC 6541). This is a star cluster roughly 22,000 light-years from Earth. It can be viewed from the southern hemisphere using binoculars. Image credit: NASA, ESA, and G. Piotto (Universitá degli Studi di Padova); Processing: Gladys Kober (NASA/Catholic University of America)

The Hubble Space Telescope turned 30 this year and NASA has celebrated the milestone by releasing dozens of newly processed images showcasing 30 galaxies, nebulae and star clusters. NASA notes of the 'celestial gems,’ ‘All of them can be seen through backyard telescopes. Some of them can also be spotted with binoculars or even the naked eye.'

The images NASA has published are spectacular. All the celestial objects belong to the Caldwell catalog, which was compiled by British amateur astronomer and science communicator Sir Patrick Caldwell-Moore. The catalog was first published 25 years ago by Sky & Telescope magazine.

Caldwell 53 (NGC 3115). 'Caldwell 53 is perhaps most notable for the supermassive black hole that lurks at its center...astronomers estimate that the black hole within Caldwell 53 has a mass roughly one billion times the mass of our Sun. This estimation means that Caldwell 53 hosts the closest billion-solar-mass black hole to Earth.' This composite image was captured using Hubble’s Advanced Camera for Surveys at infrared and visible wavelengths. Credits: NASA, ESA, and J. Erwin (University of Alabama); Processing: Gladys Kober (NASA/Catholic University of America).

Caldwell's catalog comprises 109 galaxies, star clusters and nebulae that are not included in its spiritual predecessor, the Messier catalog, named for Charles Messier. Unlike the Messier catalog, which exclusively highlights objects in the northern hemisphere, the Caldwell catalog offers targets for amateur astronomers around the world.

In total, the newly released collection includes more than 50 images captured by the Hubble Space Telescope. The images have been taken throughout Hubble's operational period and have been used for scientific research and engineering testing. The collection marks the first time the images have been fully processed for public release.

NASA states that due to Hubble's field of view, not every picture includes the entirety of a Caldwell object, and some Caldwell objects appear in multiple images. The new images join the existing Hubble gallery of Caldwell objects, which was first published in December 2019. The gallery now includes images of 87 of the 109 total Caldwell objects. In each listing included in Hubble's Caldwell catalog, an included star chart details when and where astronomers can view the object. It also explains what type of equipment will be needed.

Caldwell 45 (NGC 5248). First discovered in 1784 by William Herschel, Caldwell 45 is a spiral galaxy about 59 million light-years from Earth. NASA says, 'This stunning Hubble image of Caldwell 45 is a composite of observations made by the Wide Field Camera 3 and the Wide Field and Planetary Camera 2 in visible, infrared, and ultraviolet light. It captures the glowing red clouds where new stars are forming, scattered along the galaxy’s winding arms. These observations of Caldwell 45 were made to help astronomers learn more about gas in the galaxy’s starburst regions, as well as to better understand the structure of its nuclear rings.' Credits: NASA, ESA, J. Lee (California Institute of Technology), and A. Filippenko (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America).

The Hubble Space Telescope has had a prolific and monumental 30 years of observation in space. It was launched aboard the Space Shuttle Discovery in April 1990. During the last 30 years, spacewalking astronauts have upgraded the telescope on five occasions. Hubble remains in 'relatively stable' orbit and there is no 'set date for Hubble's retirement'. Here's hoping the 11-ton Hubble stays in orbit for many years to come.