Caldwell 87 — Globular Cluster in Horologium
NGC 1261
About C87
Description
NGC 1261 is a globular cluster in Horologium, about 53,500 light-years away. It is a moderately concentrated cluster spanning about 7 arcminutes with an integrated magnitude of 8.4.
Observing Tips
Visible as a small, round glow in a 6-inch telescope. An 8-inch scope at 150x begins to resolve the outer edges. Located in the faint constellation Horologium, best found by star-hopping from brighter neighbors. Best in autumn and winter evenings.
History
Discovered by James Dunlop on October 1, 1826 from Australia. It is one of the more remote globular clusters in the southern sky.
Fun Facts
NGC 1261's orbit takes it far from the Milky Way's center, suggesting it may have been accreted from a now-destroyed dwarf galaxy. Its chemical composition supports an extragalactic origin.
Observe
1Properties
Position & Identifiers
2How easy to spot?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Easy | Easy | Medium+ |
| 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] = -1.27 — these stars formed from gas about 19× 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: Lithopsian. License: CC BY-SA 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.
Explore Nightbase
Related knowledge, tools, and stories — no observation planning required.
