NGC 2261
NGC 2261 (also known as Hubble's Variable Nebula or Caldwell 46) is a
Observing history
The first recorded observation of the nebula was by William Herschel on 26 December 1783, being described as considerably bright and 'fan-shaped'.[2] It had long been designated as H IV 2, after being the second entry of Herschel's class 4 category for nebulae and star clusters, in his catalogues of nebulae.[3]
NGC 2261 was imaged as Palomar Observatory's Hale Telescope's first light by Edwin Hubble on January 26, 1949,[4] some 20 years after the Palomar Observatory project began in 1928. Hubble had studied the nebula previously at Yerkes and Mt. Wilson.[4] Hale had taken photographic plates with a 24-inch (60.96 cm) reflecting telescope in 1916.[5] Also, plates were taken using the same telescope in 1908 by FC Jordan, allowing Hale to use of a blink comparator to study any changes in the nebula.[5]
NGC 2261 was imaged by the Hubble Space Telescope, and an image of the nebula was released in 1999.[6]
A timelapse of NGC 2261 was taken over a period of 6 months by over 20
Descriptions
The star R Monocerotis has lit up a nearby cloud of gas and dust, but the shape and brightness slowly changes visibly even in small telescopes over weeks and months, and the nebula looks like a small comet.[8]
One explanation proposed for the variability is that dense clouds of dust near R Mon periodically block the illumination from the star.[9] This casts a temporary shadow on the nearby clouds.[10]
See also
References
- ^ a b c "NGC 2261". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-04-11.
- JSTOR 106639.
- S2CID 119513655.
- ^ a b "Citizen Science". 26 January 2009.
- ^ doi:10.1086/142284.
- ^ "Hubble's variable nebula (NGC 2261)". www.spacetelescope.org. Retrieved 2018-07-25.
- ^ "Hubble's variable nebula Project". bigamateurtelescope.com. Retrieved 2022-12-24.
- ^ "Hubble's Variable Nebula, NGC 2261". Planetary Science Institute. 2010-10-15. Retrieved 2018-07-25.
- doi:10.1086/156627.
- ^ "NGC 2261: Hubble's Variable Nebula | Science Mission Directorate". science.nasa.gov. Archived from the original on 2020-08-05. Retrieved 2018-07-25.
External links
- European Homepage for the HST – Hubble photos and information on NGC 2261
- wikispaces.com Archived 2013-02-09 at archive.today – Images by amateur astronomers
- Astrobiscuit: Seeing The Speed Of Light fun and educational video about variable nebula and the amateur community observing them
- NASA Astronomy Picture of the Day: NGC 2261: Hubble s Variable Nebula (November 8, 2017)
- NGC 2261 on