Small Sagittarius Star Cloud
![Sky map](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Jupiter_and_moon.png/20px-Jupiter_and_moon.png)
Small Sagittarius Star Cloud | |
---|---|
kly (3070 Pc) | |
Apparent magnitude (V) | 2.5[1][2] |
Apparent dimensions (V) | 2°x1°[1] |
Physical characteristics | |
Radius | ~300 ly |
Other designations | Delle Caustiche,[3] IC 4715 |
Associations | |
Constellation | Sagittarius |
The Small Sagittarius Star Cloud (also known as Messier 24 and IC 4715) is a
The
M24 fills a space of significant volume to a depth of 10,000 to 16,000 light-years. The star cloud is the most dense concentration of individual stars visible using
The light of M24 is spread out over a large area, which makes estimating its brightness difficult. Older references give the star cloud's magnitude as 4.6, but more recent estimates place it a full two magnitudes brighter, at 2.5.[1][2]
The star cloud incorporates two prominent dark nebulae which are vast clouds of dense, obscuring interstellar dust. This dust blocks light from the more distant stars, which keeps them from being seen from Earth. Lying on the northwestern side is Barnard 92, which is the darker of the two. Within the star field, the nebula appears as an immense round hole devoid of stars. American astronomer Edward Emerson Barnard discovered this dark nebula in 1913.[6] Along the northeast side lies Barnard 93, as large as Barnard 92 though less obvious. There are also other dark nebulae within M24, including Barnard 304 and Barnard 307.[2][6]
The Small Sagittarius Star Cloud also contains two planetary nebulae, M 1-43 and NGC 6567. Located within a spiral arm of the Milky Way, Messier 24 holds some similarities with NGC 206, a bright, large star cloud within the Andromeda Galaxy.[6]
See also
- Messier object
- List of Messier objects
- New General Catalogue
- Large Sagittarius Star Cloud
References
- ^ ISBN 978-1107018372.
- ^ a b c French, Sue (July 2015). "Small Sagittarius star cloud: the Sagittarius Milky Way is host to dark nebulae and open clusters". Sky & Telescope: 56.
- ^ a b "Messier 24 – the Sagittarius Star Cloud". www.universetoday.com. 3 October 2016. Retrieved 2020-10-07.
- ISBN 3211008519.
- ^ "Messier 24". messier.seds.org. Archived from the original on 2023-04-16. Retrieved 2020-09-27.
- ^ a b c d e f g "Messier 24: Sagittarius Star Cloud | Messier Objects". www.messier-objects.com. 17 April 2015. Retrieved 2018-03-21.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- Finder Chart for Messier 24
- Messier 24, SEDS Messier pages
- Merrifield, Michael. "M24 – Sagittarius Star Cloud". Deep Sky Videos. Brady Haran.
- The Sagittarius Star Cloud on