M3
NGC 5272
Dati oggetto
- Designazione catalogo
- M3
- Tipo
- GlobularCluster
- Costellazione
- Canes Venatici
- Magnitudine
- 6.2
- Ascensione retta
- 13h 42m 11.6s
- Declinazione
- +28° 22' 38.2"
- Distanza
- 33,900 anni luce
- Dimensione angolare
- 16.2
Immagine survey
Caricamento immagine survey…
Su M3
Descrizione
M3 is one of the brightest and largest globular clusters in the northern sky, located about 33,900 light-years from Earth in Canes Venatici. It contains roughly 500,000 stars in a sphere about 180 light-years in diameter. The cluster is renowned for its large population of variable stars — over 270 have been identified.
Consigli per l'osservazione
Located roughly halfway between Arcturus (Alpha Bootis) and Cor Caroli (Alpha Canum Venaticorum). Visible as a fuzzy star in binoculars. A 4-inch telescope at 100x shows a bright, round nebulous glow with a brilliant core. An 8-inch telescope resolves stars across much of the cluster, with beautiful chains radiating outward. Best observed from April through August.
Storia
Discovered by Charles Messier on May 3, 1764 — it was the first original discovery in Messier's catalog (M1 and M2 had been found by others). William Herschel resolved it into stars around 1784, counting an estimated 500 stars.
Curiosità
M3 holds the record for the most variable stars of any globular cluster, with over 270 known. Most are RR Lyrae variables, pulsating stars used as standard candles for measuring cosmic distances. The cluster is estimated to be 11.4 billion years old.
Foto della comunità (1)
Credit: Credit Line and Copyright Adam Block/Mount Lemmon SkyCenter/University of Arizona. License: CC BY-SA 3.0 us. (Wikimedia Commons)
Skybred Feb 28, 2026