NGC 7129, VdB 146, NGC 7142 - reflection nebula and open cluster in Cepheus

  Size: 2000 px      
© Velimir Popov & Emil Ivanov 2016

This image shows an area 1.77 x 1.18 deg. in the constellation Cepheus. Here is a bit of confusion with the catalogue entries of the objects (see annotated mouseover). NGC 7129 was discovered in 1794 by William Herschel with an 18.7-inch f/13 speculum telescope. He described it as "three stars about 9m involved in nebulosity. The whole takes up a space of about 1.5' diameter; other stars of the same size are free from nebulosity." Some astronomers consider NGC 7129 an open cluster, and IC 5134 - the wide dusty nebula around this cluster. Others (e.g. Magakian 2003) believe IC 5134 to be the detached part of the whole nebula. According SIMBAD, Collinder (1931), DAML02 and Archinal&Hynes (2003), NGC 7129 = Ced 196, DG 176, Cl Collinder 441, C 2140+658, Small Cluster Nebula, IV 75, h 2131, GC 4702; and IC 5134 = Ced 196, Magakian 871, VDB 146, Bernes 40, V361 Cep. Asumming this is the correct description, VdB 146 is the reflection nebula surrounding V361 Cep (BD+65 1637), which is a Herbig Ae/Be star. Despite of the confusion, one can be told: this is a young compact star forming region which shows a colorful mixture of nebulosity and bright stars against the dust clouds of the Milky Way. The distance to the complex is believed to be 3300 light years. A lot of Herbig-Haro (HH) objects can be seen on the image (see mouseover for annotations). Herbig-Haro are small emission nebulae around young developing stars (protostars). First described by American astronomer George Herbig and Mexican astronomer Guillermo Haro during the mid-1940's while studying NGC 1999, they are believed to be transient phenomena that last less than a few thousand years. With its diameter of 7.5 arc-minutes, HH 167 in Cepheus is one of the largest examples of a Herbig-Haro object.

Image details:


Center of field RA 21:42:52 (h:m:s)
Center of field DE +66:06:05 (deg:m:s)
Size 1.77 x 1.18 (deg)
Pixel scale: 2.99 (arcsec/pixel)
Orientation: Up is 101 degrees E of N
Charts and image details obtained from
Optic(s): ASA 12" Astrograph @ f/3.6 (Newton)
Mount: ASA DDM85 Standard
Camera: SBIG STL 11000 M
Filters: Luminance, Red, Green, Blue, Astronomik filters
Dates/Times: 28 Jan. 2017
Location: IRIDA Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exp. Details: R:6x10 min, G:6x10 min, B:6x10 min, Bin 2, Total Exposure Time - 180 min. (3:00 h)
More details: Dark and flat frames reduction
Processing: PixInsight / PS
Copyright: Velimir Popov and Emil Ivanov 2013 - 2016. All Rights Reserved
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