Skip to main content

Astronomers make an accidental discovery: The tiny dwarf galaxy Bedin 1

One of the amazing things about scientific research is that we don’t only learn about the things we’re looking at — sometimes we make amazing discoveries by chance as well. That’s what happened this week, when astronomers accidentally discovered a new galaxy while studying part of the Milky Way.

Astronomers were using data from the Hubble Space Telescope to study white dwarf stars in the globular cluster NGC 6752, a spherical group of stars that orbit around the core of the Milky Way. They were hoping to learn about how old the globular cluster is by studying these stars, but in the process they found something unexpected. When looking at an area right on the edge of the field of view of Hubble’s Advanced Camera for Surveys, they spotted a clump of faint stars. But on further inspection of their brightness and temperatures, the scientists realized that these stars were not a part of the globular cluster and were in fact much, much more distant.

Related Videos

The newly observed stars were in fact millions of light-years away and are part of a relatively small galaxy that is just 3000 light-years across. The galaxy is not only tiny but is also very faint, meaning that it is unlikely we would have ever discovered it had astronomers not been studying the area in front of the galaxy in detail. The new galaxy is classified as a dwarf spheroidal galaxy and has been named Bedin 1 after Luigi Bedin, an astronomer at the Italian National Institute for Astrophysics (INAF) and the leader of the team who made the discovery.

This image, taken with the NASA/ESA Hubble Space Telescope, shows a part of the globular cluster NGC 6752. The observations were made to study white dwarfs within it and to use these stars to measure the age of the globular cluster. Analyzing the data, astronomers discovered a previously unknown galaxy behind the globular cluster. The galaxy, nicknamed Bedin 1, is visible as a collection of faint stars at the top left of the image. ESA/Hubble, NASA, Bedin et al.

Bedin 1 is an unusual galaxy in that it is very isolated from others, lying 30 million light-years from the Milky Way and 2 million light-years from the nearest large galaxy, NGC 6744. This makes it likely the most isolated small dwarf galaxy discovered so far.

To get an impression of how Bedin 1 was discovered, the below video shows a zoomed in journey to globular cluster NGC 6752, with a final view captured by the Hubble of the bright stars of the cluster in the foreground and faint stars of a background galaxy behind. This background galaxy is Bedin 1, the galaxy that was found by accident.

Zooming in on NGC 6752 and Bedin 1

Editors' Recommendations

Hubble used two instruments to image this beautiful galaxy
The heart of NGC 1097, a barred spiral galaxy that lies about 48 million light-years from Earth in the constellation Fornax.

This week's image from the Hubble Space Telescope is striking: The beautiful galaxy NCG 1097, as captured using two of Hubble's instruments working in tandem. This barred spiral galaxy is located 48 million light-years away, in the constellation of Fornax, and has a twisted shape caused by gravitational interactions with a nearby companion galaxy called NCG 1097A.

This particular galaxy is known for being the site of no less than three supernovas over the past two decades, with stars exploding in epic events when they reached the ends of their lives. The supernovas were called SN 1992bd, SN 1999eu, and SN 2003B, named for the years of their observations.

Read more
Hubble images two galaxies aligned but light-years apart
The twin galaxies NGC 4496A and NGC 4496B dominate the frame in this image from the NASA/ESA Hubble Space Telescope. Both galaxies lie in the constellation Virgo, but despite appearing side-by-side in this image they are at vastly different distances from both Earth and one another. NGC 4496A is 47 million light-years from Earth while NGC 4496B is 212 million light-years away. The enormous distances between the two galaxies mean that the two are not interacting, and only appear to overlap because of a chance alignment.

This week's image shared by the team from the Hubble Space Telescope shows two galaxies that appear to be overlapping. But unlike last week's Hubble image, which showed two galaxies interacting, this week's image shows two galaxies that are actually light-years apart.

The two galaxies here are NGC 4496A, which is 47 million light-years from Earth, and NGC 4496B, which is much further away at 212 million light-years distance. The two happen to be aligned so they appear to be overlapping because they are both in the same direction from Earth, but they do not actually interact at all.

Read more
Hubble captures epic view of three galaxies merging into one
The mass of dust and bright swirls of stars in this image are the distant galaxy merger IC 2431, which lies 681 million light-years from Earth in the constellation Cancer. The NASA/ESA Hubble Space Telescope has captured what appears to be a triple galaxy merger in progress, as well as a tumultuous mixture of star formation and tidal distortions caused by the gravitational interactions of this galactic trio. A thick cloud of dust obscures the center of this image – though light from a background galaxy is piercing its outer extremities.

This week's image from the Hubble Space Telescope shows no less than three galaxies that are in the process of merging to become one, called IC 2431. Located 681 million light-years away in the constellation of Cancer, this object shows what can happen when galaxies collide and merge into each other.

The enormous gravitational forces of such a merger pull the galaxies into elongated shapes, though the process isn't entirely destructive -- there is also plentiful star formation happening in parts of the merger, with new stars being born amid the chaos. Some of the most active areas may be right in the middle of the merger, though this can't be seen in the image as a thick cloud of dust obscures the center.

Read more