  The nearby young open cluster eta Chamaeleontis has been observed by
eROSITA/SRG during its CalPV phase for 150 ks. The eROSITA data were taken in
the field-scan mode, an observing mode of Spectrum-Roentgen-Gamma (SRG) that
follows a rectangular grid-like pattern, here covering a 5x5 deg field with an
exposure depth of about 5 ks. We study the known members in X-rays and search
for potential new members of the anticipated dispersed low-mass cluster
population. Detected sources were identified by cross-matching X-ray sources
with Gaia and 2MASS, and young stars were identified by their X-ray activity,
the position in the color-magnitude diagram, and by their astrometric and
kinematic properties. X-ray-luminosities, light curves, and spectra of cluster
members were obtained and compared with previous X-ray data. Literature results
of other member searches were used to verify our new member candidates in the
observed field. We determine X-ray properties of virtually all known eta Cha
members and identify five additional stellar systems that show basically
identical characteristics, but are more dispersed. Four of them were previously
proposed as potential members; this status is supported by our X-ray study.
Based on their spatial distribution, further members are expected beyond the
sky region we surveyed. The identified stellar systems very likely belong to
the ejected halo population, which brings the total number of eta Cha cluster
members to at least 23.
