This unusual discovery, which our team around Marcel Drechsler, Xavier Strottner and Lionel Mulato made, will be explained and discussed in the following.
First of all, it should be mentioned that this image is a composite of data we created and scientific data from the GALEX satellite.
The phenomenon we discovered cannot be visualized with conventional astrophotography.

The scientific leader was Vlad Rastau from the University of Vienna.
Title: Extended far-UV emission surrounding asymptotic giant branch stars as seen by GALEX
V. Rastau, M. Mecina, F. Kerschbaum, H. Olofsson, M. Maercker, M. Drechsler, X. Strottner, and L. Mulato
Link to the scientific paper:

WHAT CAN BE SEEN IN THE IMAGE?
Our discovery involves emission shells around a special class of stars, the asymptotic giant branch (AGB) stars. The AGB phase is the final evolutionary stage of low to intermediate mass stars (0.8 < M < 8 M⊙ ) before they end up as white dwarfs with planetary nebulae. This far ultraviolet (FUV) emission has been found around eight AGB stars and show different shapes and sizes. 
As a representative of all eight structures, we have chosen to show the emission shell around the star Beta Gruis. The emission shell around the star has a diameter of 38.25 arcmin, which corresponds to an actual diameter of 120,000 astronomical units. In the case of Beta Gruis, whose shell has a kinematic age of 27,500 years, there are no traces of emissions other than those in the far ultraviolet


BETA GRUIS, JUST A REPRESENTATIVE OF A NEW CHARACTERISTIC OF AGB STARS
Like the other stars we have discovered FUV emission shells around, the second brightest star in the southern constellation Grus (Crane) is a red giant star on the asymptotic giant branch with an estimated mass of about 2.4 times that of the Sun and a surface temperature of about 3,480 K, a little more than half the surface temperature of the Sun. This low temperature is the reason for the dull red color of a type M star. Beta Gruis is a variable star (SRb), varying in brightness by about 0.4.



INTRODUCTION
Until now, the mass loss of AGB stars has been viewed as slow and continuous winds causing the formation of extended dust and gas envelopes around the stars.
However, there is growing evidence for more complex scenarios, both for the process of mass loss as a whole and for the formation of extended structures. These may be, for example, shear winds that can counter-interact with the slower wind to produce shocks and large structures. Analysis of the morphology of such extended structures can provide information about the mass-loss process and the central object. To date, only a few AGB stars have been studied in the ultraviolet (UV) region, including the famous Mira star. This project sought to expand the number of AGB stars where extended UV emission has been observed.

METHODOLOGY
This study focuses on a small sample of AGB stars that show extended FUV emission (0.13 - 0.18 μm) in the GALEX catalog. The sample was created after a systematic inspection of GALEX FUV images using Aladin on the entire sky survey (GALEX GR6/7 FUV /GR6 AIS FUV) to find previously unknown sources showing faint extended emission in this wavelength range, regardless of source type. All detections were matched to various catalogs and those associated with known objects were flagged. Here we report newly found emission associated with variable Mira, Semiregular, or Irregular type stars.


Beta Gruis / Spectral class M4.5III
Ring diameter: 38 arcminutes / 120,000 AU


U Antlia / Spectral class C-N3
Ring diameter: 6,8 arcminutes / 120,000 AU


R Dorado / Spectral class M8III:e
Mira-type variable
Ring diameter: 32 arcminutes / 90,000 AU


47 Psc / Spectral class: M3III
Ring diameter: 1.5 arcminutes / 13,000 AU


W Hya / Spectral class M7.5-9e
Size: 9 arcminutes / 48,000 AU


V* RZ Sgr / Spectral class S4,4ep
Possible interaction with SNR G354-33
Size: 16 arcminutes (inner structure) / 1 Parsec


V* DM Tuc / Spectral class M8III
Size: 11.6 arcminutes / 160,000 AU


V420 Vul / Mira Variable
Size: 10.3 arcminutes / 7.25 Parsec


Images above: far ultraviolet (FUV) on the left, visible light on the right.
GALEX catalog FUV images of the stars and their surroundings. The large, bright spots on the β Gru, R Dor, and U Ant images are from objects along the line of sight, either background stars or galaxies. The magnitude measurements are based on the absolute distances and apparent angular magnitudes of the objects, while a constant expansion velocity of 10 km s-1 or other values are also assumed when more accurate velocity measurements are available for the age determination of the extended structures. (c)V. Rastau et al, Team StDr, Lionel Mulato "Extended far-UV emission surrounding AGB stars as seen by GALEX."

As can be clearly seen, the FUV emission produces different types of structures, from well-defined rings (β Gru and RDor) to faint arcs (eye, fermata - TV Psc, W Hya, U Ant) to fuzzy faint spots (irregular - DM Tuc, RZ Sgr and V420 Vul).An important aspect is that for most of the structures no counterpart in the near UV (NUV, 0.17 - 0.30 μm) was found. The exceptions are TV Psc, which has a stronger NUV emission in the vicinity of the star, and RZ Sgr.

WHAT ARE THESE STRUCTURES?
One cause could be the wind-ISM interaction, where the emission is due to shocked molecular hydrogen.
These processes in this case are related to shocks, most likely in the form of line emission from shock-excited H2 produced by the interaction of molecular hydrogen from the cool wind with hot electrons from the gas after the shock.
The structures we describe are found around AGB stars that are nearing the end of the process of mass loss and have reached the planetary nebula stage.