 Image of the host galaxyUGC 3855 captured by theHubble Space Telescope (HST). The bright object is not a supernova but instead astar in the foreground | |
| Event type | Supernova |
|---|---|
| Ib | |
| Date | 2021 |
| Right ascension | 04h 45m 50.526s |
| Declination | +61° 59′ 33.82″ |
| Epoch | J2000 |
| Distance | ~40 mpc |
| Host | UGC 3855 |
| Notable features | closest ultra-stripped supernova |
| Total energy output |
|
SN 2021agco is was aType Ibsupernova event located in the spiral galaxyUGC 3855 at a distance of around ~40Mpc from Earth. It is the closest ultra-stripped supernova (USSN) known. It is known as an ultra-stripped SN due to the progenitor star of SN 2021agco suffered through violent mass loss with the majority of its outer layer being stripped. It was discovered in the year 2021 by a team of astronomers who were led byShengyu Yan of theTsinghua University inBeijing,China.[1]
It produced a totalkinetic energy of9.69×1049ergs and aninjection energy of8.93×1049 ergs. There was only 0.26 solar masses of supernova ejecta with2.2×10−2 solar masses ofnickel-56.[1][2]
SN 2021agco exist within an unusual environment for Ultra-stripped Supernovas. The host galaxy (UGC 3855) is around 10.6 billion years old making it and thestellar population is has relatively old. That, with its low rate ofstar formation, makes SN 2021agco located in an area where USSN's are not often found.[1]