Collecting  Photons

North is to the left. Wide field: 1600x1142

Objects:             A fantastic sculture of gas and dust. VdB 27 is the yellowish reflection nebula at the bottom, CED 30 glows in blue scattered light at the top. 

Constellation:     Taurus

Coordinates of field center (J2000): 4h 20m 43s; +27° 56'

Notes: LDN 1495 is the long dark filament that frame the image on the right. Here, strong evidences of star formation have been recently demonstrated. Within the dark filament near the lower right corner, is visible a tiny reddish nebula catalogued as HH 157 showing Herbig Haro objects embedded in the cloud. I am grateful to Sakib Rasool for these infos on the area.

Telescope and camera: ASA 10', f 3.6; TEC 140, f 7.2, SBIG STL 11000.

Exposure: ASA: L 29x10'; R 25x10'; G 21x8'; B 31x10'. TEC: L 28x10'. About 21.6 hrs total.

Date: five nights on October 2011.

Software used: acquisition, CCDsoft, FocusMax, The Sky VI. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight 1.7, Photoshop CS3. 

Processing notes: Registar was crucial to align the ASA and TEC images, since a simple affine transformation is not sufficient for a correct registration. The image shows the complete field of the ASA, while the field covered by the TEC is a bit smaller. To prepare the combined luminance I aligned the TEC subs on the ASA luminance, then the black contour of the TEC sub was rejected (CCDstack, reject range) before preparing the final sum. In this way no dark edge appeared in the final summed stack, but only a slightly worse S/N ratio.

Copyright © 2011 by Gimmi Ratto. (November 8, 2011)