  Gas detection around main sequence stars is becoming more common with around
20 systems showing the presence of CO. However, more detections are needed,
especially around later spectral type stars to better understand the origin of
this gas and refine our models. To do so, we carried out a survey of 10 stars
with predicted high likelihoods of secondary CO detection using ALMA in band 6.
We looked for continuum emission of mm-dust as well as gas emission (CO and CN
transitions). The continuum emission was detected in 9/10 systems for which we
derived the discs' dust masses and geometrical properties, providing the first
mm-wave detection of the disc around HD 106906, the first mm-wave radius for HD
114082, 117214, HD 15745, HD 191089 and the first radius at all for HD 121191.
A crucial finding of our paper is that we detect CO for the first time around
the young 10-16 Myr old G1V star HD 129590, similar to our early Sun. The gas
seems colocated with its planetesimal belt and its total mass is likely between
$2-10 \times 10^{-5}$ M$_\oplus$. This first gas detection around a G-type
main-sequence star raises questions as to whether gas may have been released in
the Solar System as well in its youth, which could potentially have affected
planet formation. We also detected CO gas around HD 121191 at a higher S/N than
previously and find that the CO lies much closer-in than the planetesimals in
the system, which could be evidence for the previously suspected CO viscous
spreading owing to shielding preventing its photodissociation. Finally, we make
estimates for the CO content in planetesimals and the HCN/CO outgassing rate
(from CN upper limits), which we find are below the level seen in Solar System
comets in some systems.
