NGC 6540
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Globular cluster NGC 6540 |
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|---|---|
| AladinLite | |
| Constellation | Sagittarius |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 18 h 06 m 07.9 s |
| declination | -27 ° 45 ′ 46 ″ |
| Appearance | |
| Concentration class | GCL |
| Brightness (visual) | 14.6 mag |
| Angular expansion | 1.5 ′ × 1.5 ′ |
| Physical data | |
| Affiliation | Milky Way |
| Radial velocity | −17.7 km / s |
| distance | 17.3 kLj |
| Core radius | 5 years |
| Metallicity [Fe / H] | −1.29 |
| history | |
| discovery | Wilhelm Herschel |
| Discovery date | May 24, 1784 |
| Catalog names | |
| NGC 6540 • C 1803-278 • ESO 456-SC53 • GC 4371 • H II 198 • Djorg 3 • VDBH 258 • Cr 364 | |
NGC 6540 is a 14.6 like brighter and originally for an open clusters held globular cluster in the constellation Sagittarius .
It is about 17,000 light-years away from Earth and was discovered on May 24, 1784 by Wilhelm Herschel with an 18.7-inch reflector telescope, who described it as "pretty faint, not large, crookedly extended, easily resolvable".