Strange radio waves emerge from direction of the galactic centre
sydney.edu.auOne of the best (IMHO) Sci-Fi books "His Master's Voice" by Stanisław Lem begins exactly like this.
"It is a densely philosophical first contact story about an effort by scientists to decode, translate, and understand an extraterrestrial transmission. The novel critically approaches humanity's intelligence and intentions in deciphering and truly comprehending a message from outer space." https://en.wikipedia.org/wiki/His_Master%27s_Voice_(novel)
Source is here: https://iopscience.iop.org/article/10.3847/1538-4357/ac2360
This is a draft/pre-print version https://arxiv.org/pdf/2109.00652.pdf
earlier discussion: https://news.ycombinator.com/item?id=28840102
Thank you, I did not see that discussion!