Sh2-254, Sh2-255, Sh2-256, Sh2-257, Sh2-258 in Orion


12" ASA - HaRGB

12" ASA - Ha

12" ASA - 100% crop

Annotated map

  Size: 2000 px Size: 2000 px Size: 2000 px Size: 2000 px  
Downloading, please wait ...
© Velimir Popov & Emil Ivanov 2013

This image shows a complex of H II regions located at 2460 parsecs (8,000 light years) away from Earth in the Perseus Arm, at the southernmost part of the Gemini OB1 association, in the constellation Orion. However, since the distance of this OB association is not known with absolute precision, being variable depending on the estimates between 1500 and 2000 parsecs, the real interaction of the region with this association is not certain. The region is composed of some clouds that optically have spheroidal aspect and seemingly are unrelated to each other, although they are very close to each other. Brightest components are Sh2-255 and Sh2-257, while Sh2 -254 is the most extensive of them. Actually the whole complex takes its name. Within this region clouds there are a phenomena of star formation, as evidenced by the presence of different sources of infrared radiation and also by the discovery of some very young open clusters.

Image details:


Center of field RA 06:12:26 (h:m:s)
Center of field DE +18:02:52 (deg:m:s)
Size 66.2 x 47.5 (arcmin)
Pixel scale: 1.8 (arcsec/pixel)
Orientation: Up is -176 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: Ha, Red, Green, Blue, Astronomik filters
Dates/Times: February 2014
Location: IRIDA Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exp. Details: Ha:20x15 min; R:8x10 min, G:10x10 min, B:8x10 min Bin 1, Total 560 min (9:20 hrs)
More details: Dark and flat frames reduction
Processing: PixInsight / PS
Copyright: Velimir Popov and Emil Ivanov 2013. All Rights Reserved
click tracking