RSGC1-F01

RSGC1-F01 is a red supergiant star in the young open cluster RSGC1 located in the constellation of Scutum. It is one of the largest stars discovered so far and also one of the most luminous cool supergiants, with a radius around Template:Convert and around 300,000 solar luminosities, with the former corresponding to a volume 3.58 billion times bigger than the Sun.Template:Efn If placed at the center of the Solar System, the photosphere would engulf the orbit of Jupiter.

The star is heavily obscured by interstellar dust and is invisible in optical wavelengths; it has only been studied through infrared and submillimeter observations.Template:Cn RSGC1 itself was discovered in 2006 using data from infrared surveys.

Observation

RSGC1-F01 is a member of the open cluster RSGC1, which is estimated to be 10–14 million years old with a total mass of about 30,000 solar masses (Template:Solar mass). All red supergiants in RSGC1 share similar initial masses (around Template:Solar mass), making the cluster a valuable for studying the evolution and mass loss of massive stars.

ALMA observations in 2024 detected CO rotational line emission from RSGC1-F01 and several other cluster members, allowing direct measurement of gas mass-loss rates and wind velocities. The wind speed for RSGC1-F01 (along with F02, F03, and F04) is Template:Val. These data have contributed to a new mass-loss rate prescription for M-type supergiants with effective temperatures between roughly 3,200 and Template:Val, showing that CO-derived rates are systematically lower than dust-based estimates.

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  Infrared image of RSGC1 cluster by Spitzer, with 2MASS image inset

See also

• Mu Cephei
• NML Cygni
• Stephenson 2 DFK 1 – mistakenly referred to as "RSGC1-01" in a 2020 paper
• VY Canis Majoris