HUBBLE SPACE TELESCOPE, 23 OCTOBER 2023
Individually, the two galaxies in this image - which lie 500 million lightyears from Earth in the constellation of Tucana - are known as NGC 7734 (top left) and NGC 7733 (bottom right). Collectively, they're known as Arp-Madore 2339-661, the moniker given to them when they were described in the Arp-Madore catalogue of peculiar galaxies, which was compiled in the 1970s and '80s.
A closer look, though, reveals that the two galaxies are actually three. Roughly two-thirds of the way along the blue upper arm of NGC 7733, you can see what appears to be a small clump of brown matter. Astronomers now believe that this is a third galaxy, provisionally now referred to as NGC 7733N. As the three galaxies are in very close proximity to one another, scientists say they will eventually merge to become one.
Denne historien er fra December 2023-utgaven av BBC Sky at Night Magazine.
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Denne historien er fra December 2023-utgaven av BBC Sky at Night Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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Could We Find Aliens by Looking for Their Solar Panels?- Designed to reflect ultraviolet and infrared, the panels have a unique fingerprint
Researchers searching for life beyond Earth spend a lot of time thinking about what telltale signs might be detectable astronomically. Forms of unambiguous evidence for the presence of life on another world are known as biosignatures. By extension, techno signatures are indicators of activity by intelligent, civilisation-building life.
Antimatter- In our continuing series, Govert Schilling looks at antimatter, the strange counterpart to most of the matter filling our Universe
Particles and corresponding antiparticles are very much alike, except they have opposite electrical charges. For instance, the antiparticle of the electron - known as the positron - has the same tiny mass, but while electrons carry a negative electrical charge, positrons are positively charged.
Where Have All The Milky Way's Early Stars Gone?- Our Galaxy has a curious lack of pristine stars
The Big Bang produced a Universe filled almost exclusively with hydrogen and helium; all other elements - what astronomers call metals - were produced by stars, supernovae and everything that happens later. So if you can pick out a pristine star with no metals polluting it from among the billions in the Milky Way, then you are likely to have a star dating from our Galaxy's earliest days.
Inside The Sky At Night - Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST
Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST. In July's Sky at Night, we discovered what she's learned since then.
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