NGC 6781
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Planetary Nebula NGC 6781 |
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| Taken with the 3.6 m telescope at the La Silla Observatory | |
| AladinLite | |
| Constellation | Eagle |
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Position equinox : J2000.0 |
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| Right ascension | 19h 18m 28.2s |
| declination | + 06 ° 32 ′ 23 ″ |
| Appearance | |
| Apparent brightness (visual) | 11.4 mag |
| Apparent brightness (B-band) | 11.8 mag |
| Angular expansion | 1.9 ′ × 1.9 ′ |
| Central star | |
| Physical data | |
| history | |
| Catalog names | |
| NGC 6781 • PK 041-02 1 • GC 4487 • H III 743 • h 2037 • | |
NGC 6781 is a planetary nebula in the constellation Eagle in the northern sky . It is between 3000 and 5000 light years away from the solar system. The central star has a mass of around 0.6 solar masses and an effective temperature of 100,000 ° Celsius, which means that most of its luminosity is in the ultraviolet spectral range.
Measurements of the radio and infrared radiation from NGC 6781 have shown that in addition to ionized gases, molecules such as carbon monoxide (CO) and hydrogen (H2) are also present in the nebula .
The object was discovered on July 30, 1788 by William Herschel .
A high-resolution image from the Hubble space telescope shows fine structures.
credentials
- ↑ NASA / IPAC EXTRAGALACTIC DATABASE
- ↑ a b SEDS : NGC 6781
- ↑ Stars and Space September 2008 p. 82
- ↑ http://deepsky.astronomie.info/Aql/ngc6781/index.de.php
- ↑ Seligman