NASA published this original story on October 16, 2024. Edits by EarthSky.
- R Aquarii is a special pair of stars, called a binary star, located 700 light-years from Earth.
- One star is a red giant, which is very big, and the other is a small white dwarf star.
- The stars have explosive eruptions, and the Hubble Space Telescope has captured amazing pictures of glowing gas filaments around them.
Hubble captures violent eruptions on R Aquarii
The Hubble Space Telescope has captured closeup images of R Aquarii, a binary star system 700 light-years away.
R Aquarii experiences violent eruptions that produce glowing gas filaments in a spiral pattern. The system consists of a red giant star and a white dwarf. The red giant is over 400 times larger than the sun.
When the white dwarf siphons hydrogen from the red giant, it causes explosive nuclear fusion on its surface. Hubble has been observing R Aquarii since 1990. NASA recently created a timelapse video showing its dynamic behavior from 2014 to 2023.
Meet R Aquarii
A binary star system called R Aquarii – located approximately 700 light-years away – undergoes violent eruptions that blast out huge filaments of glowing gas. The system demonstrates how the universe redistributes the products of nuclear energy that form deep inside stars and blasts them back out into space. The twisted stellar outflows make an interesting shape on our sky’s dome. Some say the region looks like a lawn sprinkler gone berserk. Others see it as a great cosmic bird in flight.
R Aquarii belongs to a class of double stars called symbiotic binary stars. The primary star is an aging red giant and its companion is a compact burned-out star known as a white dwarf. Astronomers classify the red giant primary star as a Mira variable. And it’s over 400 times larger than our sun. The monster star pulsates, changes temperature, and varies in brightness by a factor of 750 times over a roughly 390-day period. At its peak the star is blinding at nearly 5,000 times our sun’s brightness.
Outbursts cause geyser-like filaments
When the white dwarf star swings closest to the red giant along its 44-year orbital period, it gravitationally siphons off hydrogen gas. This material accumulates on the dwarf star’s surface until it undergoes spontaneous nuclear fusion, making that surface explode like a gigantic hydrogen bomb. After the outburst, the fueling cycle begins again.
This outburst ejects geyser-like filaments shooting out from the core, forming weird loops and trails as the plasma emerges in streamers. The force of the explosion twists the plasma and channels it upward and outward from strong magnetic fields. The outflow appears to bend back on itself into a spiral pattern. The plasma is shooting into space over 1 million miles per hour (1.6 million kph). That’s fast enough to travel from Earth to the moon in 15 minutes! Radiation from the stellar duo energize the filaments and they glow in visible light.
Hubble shows evolution of the binary star
Hubble first observed the star in 1990. R Aquarii was resolved into two very bright stars separated by about 1.6 billion miles (2.6 billion km). The ESA/Hubble team released a time-lapse of R Aquarii’s dynamic behavior, from observations spanning from 2014 to 2023. Additionally, across the five images, it’s easy to see the rapid and dramatic evolution of the binary star and its surrounding nebula. Plus, the binary star dims and brightens due to strong pulsations in the red giant star.
By the way, the scale of the event is extraordinary even in astronomical terms. Space-blasted material can be traced out to at least 248 billion miles (400 billion km) from the stars, or 24 times our solar system’s diameter.
Bottom line: Hubble captured images of R Aquarii, a binary star system 700 light-years away. It has violent eruptions that produce spiral filaments of glowing gas.
Via Hubblesite