Object description:
This nebular region in the constellation Sagittarius
is a star forming region and a small part of the large molecular cloud
Lynds 291 with a size of about 70 x 250 light
years.
The northern part of the region is dominated by red 2 H-II
emission nebulae - IC 1283 and IC 1284. The star
exciting the emission is the double star HD 167815 with spectral types B1 and
B2 III. Most of the star formation takes place at the southwestern edge of the
hydrogen cloud. IC 1283/84 was discovered by Edward Barnard in 1892 and is also
cataloged as Sharpless Sh-2 37. S 37 is part of a larger H-II region known as
Gum 78 or RCW 153.
The two smaller reflection nebulae to the southwest,
NGC 6589 (LBN 46, vdB 118) and
NGC 6595 (LBN 43, vdB 119, IC 4700), reflect light
from the B2 II star HD 167 638 and the B5 double star HD 313094/95,
respectively.
There is confusion
about the identification and names of the two small reflection nebulae. NGC
6589 was discovered by Swift in1886, but he gave a wrong position, which was
corrected by Barnard (1892). NGC 6595 was originally discovered by John
Herschel in 1830 and listed as h 2002 in his catalog in 1864.
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NGC
6595 was later observed again by Swift and - again - due to a wrong coordinate
specification by Swift in 1888 was included by Dreyer in the NGC catalog as a
separate object with the designation NGC 6590. Curiously, NGC 6590 is also
listed in the catalog as an open star cluster, but there is no star cluster in
this reflection nebula, only the central double star HD 313094/95. NGC 6590 and
NGC 6589 are therefore identical objects, the correct designation is NGC 6595.
A detailed description of the region "Star
Formation in Sagittarius: The Lynds 291 Cloud" can be found as pdf-file
in the download
here.
We also
have a wide angle view of this region, along with Messier 24,
we show that image here.
« Click here or the thumbnail to load a large annoted image
and a size comparison to the full moon. |
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