Actual image of a white dwarf feeding on material from a larger red giant 650 light years from Earth

December 14, 2018 by Evan Gough, Universe Today
This image is from the SPHERE/ZIMPOL observations of R Aquarii, and shows the binary star itself, with the white dwarf feeding on material from the Mira variable, as well as the jets of material spewing from the stellar couple. Credit: ESO/Schmid et al.

The SPHERE planet-hunting instrument on the European Southern Observatory's Very Large Telescope captured this image of a white dwarf feeding on its companion star, a type of Red Giant called a Mira variable. Most stars exist in binary systems, and they spend an eternity serenely orbiting their common center of gravity. But something almost sinister is going on between these two.

Astronomers at the ESO have been observing the pair for years and have uncovered what they call a "peculiar story." The Red Giant is a Mira variable, meaning it's near the end of its life, and it's pulsing up to 1,000 times as bright as the sun. Each it pulses, its gaseous envelope expands, and the smaller White Dwarf strips material from the Red Giant.

The binary is called R Aquarii, and it is, of course, in the constellation Aquarius. It's about 650 away from Earth.

If R Aquarii were not a binary system, and was only the red giant, it would still be a dramatic sight. In its death throes, the Mira variable pulses about once every year, and flares up to almost 1,000 times brighter than the sun. As it pulses, it expands and sheds its outer layers into , to be taken up in another generation of starbirth, some time in the future. Its core has run out of hydrogen and fusion has ceased there. Instead, fusion takes place in a shell of hydrogen that surrounds the core.

Left on its own, the Mira variable in R Aquarii would shed its outer layers as a , and in a few million years, would become a white dwarf itself. But its companion has something to say about this.

R Aquarii is called a symbiotic star system because of their relationship. As the white dwarf draws in material from the Red Giant, it ejects some if it in weird looping patterns, seen in this Hubble image. Credit: Judy Schmidt, USA – Symbiotic System R Aquarii, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=63473035

The Mira variable's companion in this binary system is a white dwarf. It's smaller, denser, and much hotter than the Mira variable. It steals stellar material from the Mira star and sucks it in with its gravity. It then sends jets of material out into space.

As if that wasn't enough for this strange pair, the white dwarf has some fireworks of its own. Sometimes, enough material—mostly hydrogen—from the Mira variable star collects on the surface of the white dwarf, and triggers a thermonuclear nova explosion. The explosion expels more material out into space, adding to the spectacle. The remnants of past nova events can be seen in the tenuous nebula of gas radiating from R Aquarii in this image.

The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument that captured the main image is a planet-hunting instrument, with the power to directly image exoplanets. But that's not all it can do. The same power that makes it able to image exoplanets also means it can a wide variety of other astronomical objects, including R. Aquarii.

SPHERE wasn't the only instrument looking at the odd binary pair. The Hubble has also been looking at the white dwarf feeding on its companion, several times over the years. Below is a three-part image showing how the 'scopes worked together to understand this system.

This image shows part of the wide-field observation from Hubble compared with the intricate details uncovered by the unparalleled observational capabilities of SPHERE and the VLT. Credit: ESO/Schmid et al./NASA/ESA

Explore further: R Aquarii: Watching a volatile stellar relationship

More information: ESO Press Release: Dancing with the Enemy, www.eso.org/public/news/eso1840/

Related Stories

R Aquarii: Watching a volatile stellar relationship

June 6, 2017

In biology, "symbiosis" refers to two organisms that live close to and interact with one another. Astronomers have long studied a class of stars—called symbiotic stars—that co-exist in a similar way. Using data from NASA's ...

'Wonderful' star reveals its hot nature

April 28, 2005

For the first time an X-ray image of a pair of interacting stars has been made by NASA's Chandra X-ray Observatory. The ability to distinguish between the interacting stars – one a highly evolved giant star and the other ...

Ultra-close stars discovered inside a planetary nebula

October 23, 2018

An international team of astronomers have discovered two stars in a binary pair that complete an orbit around each other in a little over three hours, residing in the planetary nebula M3-1. Remarkably, the stars could drive ...

Search for stellar survivor of a supernova explosion

March 30, 2017

Astronomers have used the NASA/ESA Hubble Space Telescope to observe the remnant of a supernova explosion in the Large Magellanic Cloud. Beyond just delivering a beautiful image, Hubble may well have traced the surviving ...

NASA’s STEREO spots a new nova

May 1, 2012

While on duty observing the Sun from its position in solar orbit, NASA’s STEREO-B spacecraft captured the sudden appearance of a distant bright object. This flare-up turned out to be a nova — designated Sagittarii ...

Recommended for you

10 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

jonesdave
3 / 5 (6) Dec 14, 2018
Awesome! Science rocks! And this is why it is infinitely preferable to crank and pseudo-science.
Da Schneib
2.6 / 5 (5) Dec 15, 2018
And getting in before the nutjobs, this is data not theory. We can see it.
Surveillance_Egg_Unit
2.3 / 5 (3) Dec 15, 2018
The reality of the Natural Order would still be awesome, even long before scientists learned of it.
The Cosmos is but one part of the story.
Da Schneib
2 / 5 (4) Dec 15, 2018
The lizards did it and we can't tell because we don't have aluminum foil over our windows.
Solon
1.8 / 5 (5) Dec 15, 2018
"We can see it."

Yes, the instruments can detect something happening out there but is the interpretation of what is being detected correct? The interpretation is based on models that rely on assumptions that originated in the early days of astronomy when plasma and electricity and magnetic fields in space were not even considered, but are now accepted. Alternative interpretations MUST be considered if this is to be accepted as real science.
Surveillance_Egg_Unit
2.3 / 5 (3) Dec 15, 2018
@Solon
The early origination in the early days is of little importance now. However, as usual - some science fact was not accepted before the advent of new instruments with superior detection and imaging. And now it is the clarity of the imaging that satisfies the scientists who were reluctant to accept much of what had been presented to them in the earlier days. So now they have their proof for plasma, magnetic fields, EM and electric currents, etc. - in addition to the power of gravity.

I am amazed at the clarity in the first photo after having zoomed into it as far as it can go.
The blob then becomes a perfectly clear shot of 2 separate orbs that are so close together, but that there is no mistaking that there are 2 orbs and not 1, and that a length of matter is being extruded from one or both. And it is further proof that everything in the Universe is following its programme in the Natural Order of Life and Death and Rebirth.
qraal01
5 / 5 (2) Dec 15, 2018
So the alternative explanation is?

"We can see it."

Yes, the instruments can detect something happening out there but is the interpretation of what is being detected correct? The interpretation is based on models that rely on assumptions that originated in the early days of astronomy when plasma and electricity and magnetic fields in space were not even considered, but are now accepted. Alternative interpretations MUST be considered if this is to be accepted as real science.

V4Vendicar
not rated yet Dec 15, 2018
Two eyes in the dark.
Surveillance_Egg_Unit
2.3 / 5 (3) Dec 16, 2018
Two eyes in the dark.
says V4V
Surveillance_Egg_Unit
2.3 / 5 (3) Dec 16, 2018
Chuckling at the thought - but yes, you could say that they look like a pair of eyes. There seem to be many such pairs of eyes in the Cosmos - as we are told that binaries are common. But this - this may be unique in that they are soooo close together with a small separation in between that they must have already joined together long ago - into one.
We are only now seeing them as they were then - thanks to SPHERE/ZIMPOL

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.