TY  - JOUR
A1  - Hillwig, Todd C.
A1  - Reindl, Nicole
A1  - Rotter, Hannah M.
A1  - Rengstorf, Adam W.
A1  - Heber, Ulrich
A1  - Irrgang, Andreas
T1  - Two evolved close binary stars: GALEX J015054.4+310745 and the central star of the planetary nebula Hen 2-84
JF  - Monthly notices of the Royal Astronomical Society
N2  - As part of a survey to find close binary systems among central stars of planetary nebula, we present two newly discovered binary systems. 
GALEX J015054.4+310745 is identified as the central star of the possible planetary nebula Fr 2-22. We find it to be a single-lined spectroscopic binary with an orbital period of 0.2554435(10) d. 
We support the previous identification of GALEX J015054.4+310745 as an sdB star and provide physical parameters for the star from spectral modelling. We identify its undetected companion as a likely He white dwarf. Based on this information, we find it unlikely that Fr 2-22 is a true planetary nebula. In addition, the central star of the true planetary nebula Hen 2-84 is found to be a photometric variable, likely due to the irradiation of a cool companion. The system has an orbital period of 0.485645(30) d. 
We discuss limits on binary parameters based on the available light-curve data. 
Hen 2-84 is a strongly shaped bipolar planetary nebula, which we now add to the growing list of axially or point-symmetric planetary nebulae with a close binary central star.
KW  - binaries: close
KW  - stars: individual: GALEX J015054.4+310745
KW  - subdwarfs
KW  - planetary nebulae: individual: Hen 2-84
Y1  - 2022
U6  - https://doi.org/10.1093/mnras/stac226
SN  - 0035-8711
SN  - 1365-2966
VL  - 511
IS  - 2
SP  - 2033
EP  - 2039
PB  - Oxford Univ. Press
CY  - Oxford
ER  -