NGC 2261
Variable fog ( reflection fog ) | |
---|---|
NGC 2261 | |
Photo from the Hubble Space Telescope | |
Constellation | unicorn |
Position equinox : J2000.0 |
|
Right ascension | 06h 39m 09.5s |
declination | + 08 ° 44 ′ 40 ″ |
Further data | |
Brightness (visual) |
9.0 likes |
Angular expansion |
3 ′, 0 × 2 ′, 0 |
distance |
2600 ly |
history | |
discovery |
William Herschel |
Date of discovery |
December 26, 1783 |
Catalog names | |
NGC 2261 • Caldwell 46, H IV 2, h 399, GC 1437 | |
Aladin previewer |
NGC 2261 (also Hubble's Variable Nebula and Caldwell 46 ) is a variable reflection nebula in the constellation Monoceros , which is about 2,600 light-years from the sun away. It is illuminated by a young giant star of the spectral type B0 called R Monocerotis (R Mon), but which is not itself visible.
NGC 2261 was photographed as the " first light " of the Hale telescope by Edwin Hubble on January 26, 1949. Hubble had already studied the nebula at the Yerkes and Mount Wilson observatories .
One thesis for the variability are dense dust clouds in the vicinity of R Mon, which periodically block its illumination.
The object was discovered by Wilhelm Herschel on December 26, 1783 .
Web links
- Spektrum.de : Amateur recordings [1]
Individual evidence
- ↑ NASA / IPAC EXTRAGALACTIC DATABASE
- ↑ SEDS : NGC 2261
- ↑ SuW 01.2017 p. 58ff
- ↑ a b http://365daysofastronomy.org/2009/01/26/january-26-60th-anniversary-of-hale-telescope-first-light/
- ↑ SAO / NASA ADS Astronomy Abstract Service (ed.): A model for the cometary nebula NGC 2261 . bibcode : 1978ApJ ... 226..455A .
- ↑ Seligman