Caldwell 48

Majestic Caldwell 48 offers a color contrast with its bright-yellow heart and sparkling young, hot, blue stars in its dusty spiral arms.

Distance

67 million light-years

Apparent Magnitude

11.0

constellation

Cancer

object type

Spiral Galaxy

Caldwell 48
The spiral pattern shown by the galaxy in this image from the NASA/ESA Hubble Space Telescope is striking because of its delicate, feathery nature. These "flocculent" spiral arms indicate that the recent history of star formation of the galaxy, known as NGC 2775, has been relatively quiet. There is virtually no star formation in the central part of the galaxy, which is dominated by an unusually large and relatively empty galactic bulge, where all the gas was converted into stars long ago. NGC 2275 is classified as a flocculent spiral galaxy, located 67 million light-years away in the constellation of Cancer.  Millions of bright, young, blue stars shine in the complex, feather-like spiral arms, interlaced with dark lanes of dust. Complexes of these hot, blue stars are thought to trigger star formation in nearby gas clouds. The overall feather-like spiral patterns of the arms are then formed by shearing of the gas clouds as the galaxy rotates. The spiral nature of flocculents stands in contrast to the grand design spirals, which have prominent, well defined-spiral arms.
ESA/Hubble & NASA, J. Lee and the PHANGS-HST Team; Acknowledgment: Judy Schmidt (Geckzilla)

Caldwell 48, also known as NGC 2775, is a spiral galaxy. This image of Caldwell 48 combines visible, infrared, and ultraviolet observations taken by Hubble’s Wide Field Camera 3 in 2019. It features the galaxy’s large, yellowish, central bulge filled with old stars, encircled by tightly wound spiral arms decorated by dark dust and clusters of young, blue stars. Astronomers used Hubble to study young stars in the galaxy’s spiral arms to better understand star formation there.

Caldwell 48 has an apparent magnitude of 11 and is located 67 million light-years away in the constellation Cancer. It was discovered by astronomer William Herschel in 1783 and is visible in clear, dark skies using a small telescope. Resolving its spiral arms, however, is incredibly difficult even with a large telescope. The best time of year to observe it is late winter in the Northern Hemisphere or late summer in the Southern Hemisphere.

For more information about Hubble’s observations of Caldwell 48, see:
Birds of a Feather

A star chart shows C48 to the bottom-left of the constellation Cancer in the southern night sky at 10pm in March.
This star chart for Caldwell 48 represents the view from mid-northern latitudes for the given month and time.
Image courtesy of Stellarium
A star chart shows C48 to the upper-right of the constellation Cancer in the southern night sky at 10pm in March.
This star chart for Caldwell 48 represents the view from mid-southern latitudes for the given month and time.
Image courtesy of Stellarium

Glossary

Apparent Magnitude - The brightness of an astronomical object as seen from Earth, influenced by the object's distance from Earth, its absolute magnitude, and even gas and dust that lie between the object and Earth.

Galactic Bulge - A dense collection of stars at the center of a spiral galaxy, possibly hosting a supermassive black hole.

Spiral Galaxy - A galaxy characterized by its spiral structure, with star-filled arms that extend out from the center of the galaxy and host regions of star formation.

Explore Hubble's Caldwell Catalog

The following pages contain some of Hubble’s best images of Caldwell objects.

Stars with four diffraction spikes dot the scene against a black backdrop.

Caldwell 1

Also known as NGC 188, this group of stars formed from a large cloud of gas making the stars roughly…

Red cloud of dust with a bright white star in the center of it. Lots of reddish and orangish stars in the background.

Caldwell 2

This shell of gas is expanding outward, away from the dying star within.

Large grouping of bright white, blue and red stars. Lightly colored blue dust surrounds the stars.

Caldwell 3

This barred spiral galaxy was first spotted by British astronomer William Herschel in April 1793 in the constellation Draco.