. "PSR B1620-26 System"@en . . . "A helium white dwarf and a pulsar in the middle of the crowded core of the M4 star cluster, around which , the oldest known planet, nicknamed \"Methuselah, orbits. It was formed only 1 Billion Years after the big bang and is 13 Billion years old. The planet may be a brown dwarf."@en . "A helium white dwarf and a pulsar in the middle of the crowded core of the M4 star cluster, around which , the oldest known planet, nicknamed \"Methuselah, orbits. It was formed only 1 Billion Years after the big bang and is 13 Billion years old. The planet may be a brown dwarf."@en . .