Messaging and broadcasting via Cepheid Variable and a possible chat with extraterrestrial civilization. All they would have to do is waiting for us to login to the real broadband of the connected Universe which is Cepheid Variables: A Galactic Internet. If we want to contact not just a few highly targeted systems, but instead send a signal intended for everyone in the galaxy through this pulsar as modem, Cepheid variables is one of the other “standard candles” for measuring inter-galactic distances. The pulsars are good navigational beacons over galactic and intergalactic distances but are a effective way to broadcast a ‘message’ in terms of its luminosity and accessibility. One advantage of using Cepheids would be that astronomers in other civilizations are likely to be looking at them since they are a valuable tool in determining distances between galaxies.
Hubble tracks down Cepheid variable stars in M100. The Cepheid star in the center of the box is located in a star forming region of the spiral arm of the galaxy M100.
"We propose that a sufficiently advanced civilization may employ Cepheid variable stars as beacons to transmit all-call information throughout the galaxy and beyond. One can construct many scenarios wherein it would be desirable for such a civilization of star ticklers to transmit data to anyone else within viewing range. The beauty of employing Cepheids is that these stars can be seen from afar(we monitor them out through the Virgo cluster), and any developing technological society would seem to be likely to closely observe them as distance markers. Records exist of Cepheids for well over one hundred years. We propose that these (and other regularly variable types of stars) be searched for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional signaling. "
Above is excerpt from Paper "The Cepheid Galactic Internet" by John G. Learned, R-P. Kudritzki, Sandip Pakvasa, A. Zee
Centauri Dreams, post as:
Making contact with an extraterrestrial civilization, whether by microwave, laser or neutrino, highlights the problem of time. Suppose you are looking for a newly emerging technological culture around another star. When do you transmit? After all, even the most powerful signal sent to Earth a million years ago would have no listeners, which is why some have suggested putting actual artifacts in promising solar systems. Rather than transmitting over time-scales measured in eons, you leave an object that can be decoded and activated for communications. All kinds of interesting science and science fictional scenarios flow from that idea.