Stephenson 2 DFK 1

Rare card · No. 51491

Stephenson 2 DFK 1 is a red supergiant (RSG) or possible extreme red hypergiant (RHG) star in the constellation of Scutum. It lies near the open cluster Stephenson 2, which is located about 5.8 kiloparsecs (19,000 light-years) away from Earth in the Scutum–Centaurus Arm of the Milky Way galaxy. Although older studies have categorised it as an unrelated or foreground red supergiant, it is now generally accepted to be a member of its cluster. At a radius of roughly 1,840 times that of the Sun (R☉), corresponding to a volume around 6.26 billion times that of the Sun, it is one of the largest known stars. If placed at the center of the Solar System, its photosphere would extend past the orbit of Jupiter and almost reach the orbit of Saturn. It is also one of the most luminous and coolest red supergiants known, with a luminosity 321,000 times that of the Sun (L☉) and an effective temperature of 3,200 K respectively.

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