Autore dello sfondo:
John Ebersole
19 May 2026
M21
The open star cluster, M21, at image center is rather inconspicuous compared to the surrounding nebulae, including M8, M20, Sh2-29, and Sh2-34 at image right, that I recently named the Forgotten Nebula. It suffers the fate of many nice nebulae that are close to famous ones.
Dataset da cui è stata elaborata l'immagine
M21
8 credit
- Tipo di obiettivo............................................................................................................................Emission Nebula
- Fotocamera............................................................................................................................FLI PL16803
- Coordinate dell'obiettivo............................................................................................................................RA 271.0542 Dec -22.48333
- Emisfero............................................................................................................................Southern
- Posizione del telescopio............................................................................................................................Australia
- Evento transitorio............................................................................................................................No
- Osservato il............................................................................................................................19 Jun 2021 - 17 Apr 2022
Filtro | Exp. media (s) | Esposizione totale | Sottoframe |
|---|---|---|---|
| SII | 600 | 3h40m | 22 |
| Halpha | 600 | 3h40m | 22 |
| OIII | 600 | 3h40m | 22 |