What is stephenson 2-18?

Stephenson 2-18 (also known as Stephenson 2-DFK 1 or RSGC2-18) is a red supergiant star located within the Stephenson 2 open cluster. It is considered one of the largest known stars, and one of the most luminous red supergiants known.

Here's a breakdown of important facts:

• Type of Star: It is classified as a <a href="https://www.wikiwhat.page/kavramlar/Red%20Supergiant">red supergiant</a>, a late-stage evolved massive star.

• Size: Estimates suggest that its radius is around 2,150 times that of the Sun. If placed at the center of our Solar System, its photosphere would engulf the orbit of Saturn.

• Luminosity: Its luminosity is estimated to be over 400,000 times that of the Sun, making it an extremely luminous star. This information changes according to study.

• Location: It is located within the <a href="https://www.wikiwhat.page/kavramlar/Stephenson%202%20Cluster">Stephenson 2 Cluster</a>, a young open cluster situated approximately 19,000 light-years away in the constellation Scutum.

• Distance: The star's extreme distance and the obscuring effects of interstellar dust make precise measurements of its properties challenging. This means estimates of its size and luminosity can vary between studies.

• Variability: It's a variable star, meaning its brightness fluctuates over time, though the nature and period of this variability are not fully characterized. The star's <a href="https://www.wikiwhat.page/kavramlar/Variability">Variability</a> is due to the instability of its outer layers.