5 papers
Discovery of a nebula associated with a high proper motion sdB star
R. Ortiz, F. Bijarchian, M. A. Guerrero +2
All B-type subdwarf stars (hereafter sdB) should have low flux of ionizing photons, making them incapable of producing a noticeable circumstellar photoionized shell. However, a few…
Planetary Nebulae in the eROSITA eRASS1 catalog
Haoyang Yuan, Martin A. Guerrero, Quentin Parker +1
Some planetary nebulae (PNe) host X-ray-emitting hot bubbles shaped by stellar wind interactions and/or harbor X-ray-emitting central stars due to accretion, shocks within their fa…
CGCS 6306, another X-ray-emitting asymptotic giant branch star confirmed to be a symbiotic binary
Jaroslav Merc, MartÃn A. Guerrero, Jesús A. Toalá +1
A number of asymptotic giant branch (AGB) stars are known to exhibit UV excess and/or X-ray emission. These have been considered signposts of a hot white dwarf (WD) companion in a…
Y Gem, a symbiotic star outshone by its asymptotic giant branch primary component
M. A. Guerrero, D. A. Vasquez-Torres, J. B. RodrÃguez-González +2
A considerable number of asymptotic giant branch (AGB) stars exhibit UV excess and/or X-ray emission that indicates a binary companion. AGB stars are so bright that they easily out…
Accretion onto WD 2226210, the central star of the Helix Nebula
S. Estrada-Dorado, M. A. Guerrero, J. A. Toalá +4
The central star of the Helix Nebula, WD 2226210 presents enigmatic hard X-ray emission and mid-IR excess. The latter has been attributed to a dusty disk or a cloud-like structu…