NGC 6717
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Globular cluster NGC 6717 |
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| Photo from the Hubble Space Telescope | |
| AladinLite | |
| Constellation | Sagittarius |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 18 h 55 m 06.0 s |
| declination | -22 ° 42 ′ 06 ″ |
| Appearance | |
| Concentration class | VIII |
| Brightness (visual) | 8.4 mag |
| Angular expansion | 5.4 ' |
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Color excess E (BV) (redness) |
0.22 |
| Physical data | |
| Affiliation | Milky Way |
| Radial velocity | 22.8 km / s |
| distance | 23.1 kLj (7.1 kpc ) |
| Absolute brightness | −5.67 mag |
| Core radius | 0.08 |
| Tidal radius | 9.87 |
| Concentration lg (r t / r c ) | 2.07 |
| Metallicity [Fe / H] | −1.29 |
| history | |
| discovery | William Herschel |
| Discovery date | August 7, 1784 |
| Catalog names | |
| NGC 6717 • IC 4802 • C 1852-227 • GCl 105 • ESO 523-SC014 • GC 4444 • Pal 9 • Cr 395 • OCL 37 | |
NGC 6717 is a globular cluster in the constellation Sagittarius that was discovered by Friedrich Wilhelm Herschel on August 7, 1784 .
It is at a distance of 7100 pc from the earth . The globular cluster, which has an apparent magnitude of 8.4 m , is located directly south of the star ν 2 Sagittarii. The bright star region on the northeastern edge has the separate designation IC 4802 .
Individual evidence
- ↑ NASA / IPAC EXTRAGALACTIC DATABASE
- ↑ a b c SEDS: NGC 6717
- ↑ a b c d e www.mporzio.astro.it ( Memento from June 29, 2007 in the Internet Archive )
- ↑ SEDS_Palomar 9
- ↑ Seligman
- ↑ The Palomar globular cluster