NGC 6540
| Kugelsternhaufen NGC 6540 | |
|---|---|
 (c) Credit: ESA/Hubble & NASA, R. Cohen, CC BY 4.0 | |
| Aufnahme von NGC 6540 mithilfe des Hubble-Weltraumteleskops | |
| AladinLite | |
| Sternbild | Schütze |
| Position Äquinoktium: J2000.0, Epoche: J2000.0 | |
| Rektaszension | 18h 06m 07,9s [1] |
| Deklination | −27° 45′ 46″ [1] |
| Erscheinungsbild | |
| Konzentrationsklasse | GCL [2] |
| Helligkeit (visuell) | 14,6 mag [2] |
| Winkelausdehnung | 1,5′ × 1,5′ [2] |
| Physikalische Daten | |
| Zugehörigkeit | Milchstraße |
| Radialgeschwindigkeit | −17,7 km/s |
| Entfernung | 17,3 kLj |
| Kernradius | 5 Lj. |
| Metallizität [Fe/H] | −1,29 |
| Geschichte | |
| Entdeckung | Wilhelm Herschel |
| Entdeckungsdatum | 24. Mai 1784 |
| Katalogbezeichnungen | |
| NGC 6540 • C 1803-278 • ESO 456-SC53 • GC 4371 • H II 198 • Djorg 3 • VDBH 258 • Cr 364 | |
NGC 6540 ist ein 14,6 mag heller und ursprünglich für einen offenen Sternhaufen gehaltener Kugelsternhaufen im Sternbild Schütze.
Er ist etwa 17.000 Lichtjahre von der Erde entfernt und wurde am 24. Mai 1784 von Wilhelm Herschel mit einem 18,7-Zoll-Spiegelteleskop entdeckt,[3] der ihn dabei mit „pretty faint, not large, crookedly extended, easily resolvable“[4] beschrieb.
Weblinks
- Hubble Spies a Scintillating Globular Cluster (engl.)
- NGC 6540. SIMBAD, abgerufen am 7. September 2016 (englisch).
- NGC 6540. DSO Browser, abgerufen am 7. September 2016 (englisch).
Einzelnachweise
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(c) Credit: ESA/Hubble & NASA, R. Cohen, CC BY 4.0
Hubble Spies a Scintillating Globular Cluster
This scintillating image showcases the globular cluster NGC 6540 in the constellation Sagittarius, which was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys. These two instruments have slightly different fields of view — which determines how large an area of sky each instrument captures. This composite image shows the star-studded area of sky that was captured in both instruments’ field of view.
NGC 6540 is a globular cluster, a stable, tightly bound multitude of stars. The populations of these clusters can range from tens of thousands to millions of stars, all of which are trapped in a closely-packed group by their mutual gravitational attraction.
The brightest stars in this image are adorned with prominent cross-shaped patterns of light known as diffraction spikes. These astronomical embellishments are a type of imaging artefact, meaning that they are caused by the structure of Hubble rather than the stars themselves. The path taken by the starlight as it enters the telescope is slightly disturbed by its internal structure, causing bright objects to be surrounded by spikes of light.
Hubble peered into the heart of NGC 6540 to help astronomers measure the ages, shapes, and structures of globular clusters towards the centre of the Milky Way. The gas and dust shrouding the centre of our galaxy block some of the light from these clusters, as well as subtly changing the colours of their stars. Globular clusters contain insights into the earliest history of the Milky Way, and so studying them can help astronomers understand how our galaxy has evolved.
Credit:
ESA/Hubble & NASA, R. Cohen