The BD eventually included 324,188 stars to about magnitude 9.5. The BD, with its detailed star charts to 9th or 10th magnitude and its reliable, well-checked list of positions, remained an essential everyday tool of working astronomers for nearly a century. Durchmusterung designations are still often encountered. The star magnitudes in these catalogs, however, are notoriously unreliable by modern standards. Most were merely quick eyeball estimates.
Variable stars have a naming system all their own.
This too was instigated by the energetic Argelander. He denoted the first variable star found in a constellation by the capital letter R with the genitive of the constellation name, since the previous letter, Q, was the highest Bayer had gone in Roman star lettering. If a variable already had a Greek letter, Argelander left it alone. Even these 334 designations proved insufficient for the variables in some crowded constellations. Rather than start an even more awkward three-letter system, astronomers ruled that further variables in a constellation would simply be designated V335, V336, and so on forever.