For over 30 years, astronomers were baffled by a star called HD 44179, surrounded by a mysterious rectangular-shaped nebula. Nebulas, or clouds of gas and dust, often form around stars that are nearing the end of their lives. Astronomers couldn't figure out what was causing the nebula's strange shape.
In a new image of the "Red Rectangle" — the most detailed image yet — it's confirmed that the cloud is not actually rectangular. It's shaped like an "X" with streams of glowing gas that line up like rungs on a ladder.
What makes this nebula look so strange? In 2007, astronomers believed that molecular forces inside the cloud must be causing its strange shape. But with this detailed image from the Hubble Space Telescope, we now have new insights into what might be influencing its structure.
"It also appears that the star is a close binary that is surrounded by a dense area of dust — both of which may help to explain the very curious shape," NASA explains.
A neighboring star and a clump of dense stuff might be causing the nebula to stretch out like that.
The star will eventually run out of gas and turn into a white dwarf, emitting tons of ultraviolet radiation. That radiation will cause the surrounding nebula to glow.
h/t Live Science