SIMBAD references

IX Del is a variable star that was classified as uncertain E/SD at the Variable Star Index. The SSV-UAI-GRAV (Unione Astrofili Italiani, Variable Star Section) suggested a campaign to observe the star in order to understand its true nature. The Štefánik and Ďáblice observatories in Prague also collaborated in the observing campaign of the Italian section. From 2024 August to 2024 September, 10 observing sessions were obtained with terrestrial telescopes and V-band CCDs. From the analysis of the data thus obtained, combined with the Zwicky Transient Facility data, the star IX Del has been reclassified as an RRab-type variable with a pulsation period of 0.540914 day and a range of 1.36 mag g. The Blazhko effect from the result of this work is evident.