Caldwell 105 — Globular Cluster in Musca
NGC 4833
About C105
Description
NGC 4833 is a globular cluster in Musca, about 21,200 light-years away. It spans about 14 arcminutes and shines at magnitude 7.4. The cluster lies behind significant foreground dust, which reddens and dims it somewhat.
Observing Tips
Visible as a moderately bright, round glow in a 4-inch telescope. An 8-inch scope resolves the outer stars. The foreground dust gives the cluster a slightly reddened appearance. Best from southern latitudes in autumn and winter.
History
Discovered by Nicolas Louis de Lacaille in 1751 from South Africa. It is one of the more obscured globular clusters in this part of the sky due to intervening Milky Way dust.
Fun Facts
NGC 4833 is one of the more metal-poor globular clusters in the Milky Way, suggesting it is among the oldest. Its position behind moderate interstellar extinction has historically made precise measurements challenging.
Observe
1Properties
Position & Identifiers
2How easy to spot?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Easy | Easy | Easy |
| 150 mm Newton 150mm Newt. | Easy | Easy | Easy |
| Celestron C8 (203 mm SCT) C8 203mm | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
3Visibility
Set a location in User Settings to see visibility data.
4
Eyepiece View
5
Best Magnification
6Metallicity
[Fe/H] = -1.85 — these stars formed from gas about 71× poorer in iron than the Sun.
7Concentration class
Shapley-Sawyer class VI — moderately concentrated core.
Explore
8
Classification Decoder
Discover
9
Light Travel Time Machine
10
Relativistic Travel
Community Photos (1)
Credit: ESA/Hubble and NASA. License: CC BY 4.0. (Wikimedia Commons)
Skybred Mar 2, 2026
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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