Collecting  Photons

Roll over to see the Hα channel

Portrait: north on the right 1600x1223

Objects:             NGC 1909 (reflection nebula) on the Hα background of the periphery of the south end of the Barnard loop.

Constellation:     Orionis

Coordinates of field center: 5h 5m +7° 20'

Notes: this is the ghost on which Rigel light reflects. Here I was not only interested in the reflection itself but also on the extremely faint extensions of the Barnard loop that cross the area and, I suspected, were associated with the reflection nebula. Indeed, the larger image show that the Hα fluorescence surrounds nicely the reflections showing a denser band, in a similar way, for example, to what is found around B33 or the dark lane that surrounds VdB 142.
 

Telescope and camera: Megrez 80 super apo with the Televue 0.8x flattener (80-384 mm f 4.8); SBIG STL 11000.

Exposure: Luminance 43x8'; R, B 14x10'; G 14x8'; Hα bin 2x2 21x16'. Almost 18 hrs total.

Date: 6 nights on 12,15, 19-12-09, 15, 18, 21-01-10.

Software used: acquisition, CCDsoft. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight, Photoshop CS. 

Processing notes: processing was complicated by the sub-optimal instrumentation: the TV flattener is computed to cover a DSRL field (22.2x14.8 mm), while this image covered 28.1x22.1 mm. The correction was non ideal but relatively acceptable, while the corners presented sever illumination problems that were only partially corrected by flat fielding.

Copyright © 2010 by Gimmi Ratto. (January 24, 2010)