Collecting Photons

M81, M82, NGC 3077 (Ursa Major)

Roll over to see the IFN

Full resolution galaxies 1600x1177

Full resolution galaxies and IFN 1600x1177

Objects: M81, M82, NGC 3077 and the overlying integrated flux nebula

Constellation: Ursa Major

Coordinates of field center (J2000): h 57m 23s +69° 18' 22"

Notes: Three main galaxies: M82 (Sd, 11.2'x4.3'), M81(Sb, 24.9'x11.5'), NGC 3077 (Sd, 5.2'x4.7'), a small irregular satellite Holmberg IX (Irr, 2.6'x2.2') and countless smaller blips. Some interesting HII regions far, far away, a diffuse reflection nebula covering the entire field. Plenty of stuff to look at, then!

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

Exposure: Luminance 167x8'; Hα 60x16';R, B 20x10'; G 20x8'. About 47.6 hrs total.

Date: 15 nights in December, January and February 2009-2011.

Software used: acquisition, CCDsoft, The Sky 6, CCDcommander. Calibration; registration and stacking: CCDstack; processing: PixInsight LE, Photoshop CS.

Inverted and equalised view of the IFN

Full resolution view of M81 and Holmberg IX

Full resolution view of M82

Past visit to the area: a personal historical record

These images are totally sub-par and are here only for personal record.

2005 - NGC 3031 - M 81 (Ursa Major)

One of the great wonders of sky. Large (26'X14') and bright (6.9) with a marvellous colour contrast between spiral arms and dustier nucleus. Notice several dark lanes and numerous blue stars resolved in the arms. The faint path on the left is the galaxy Holmberg II: this is a dwarf galaxy in the M81 group.

31X8' over 4 hours of exposure, iso 400. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS. Canon 300D, C8 f 6.3. Published on the July 2005 issue of "Le Stelle".

2005 - NGC 3034 - M 82 (Ursa Major)

A peculiar and very active galaxy nearby M81(13'X6').

37X8', iso 400. The stack has been processed with the aim of maximizing resolution and colour differences. In brief the final image is the composite of a luminance layer obtained by converting the added stack to black and white and then processing through a Richardson-Lucy algorithm. The chroma layer has been processed through a hyperbolic sine stretch. Final composition in the Lab mode in Photoshop CS. Canon 300D, C8 f 6.3. Published on the July 2005 issue of "Le Stelle".

2006 - Region of M81 - 82 (Ursa Major)

Wide field image. On the top-left corner is visible the associated galaxy ngc 3077 (5.2'x4.7').

Megrez 80, 600 mm, 350D, 36X8' over 4 hours of exposure, iso 800. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS.

2007 - M81 - 82 (Ursa Major)

A mosaic of this lovely couple made with the C8 and the 350D. The shot has been taken in bad weather so it took 4 nights to collect a very unimpressive total of 53X8' sub-exposures. In spite of the relatively short integration time, the result is reasonably decent.

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Send anything that comes to mind to Gimmi Ratto gimmi@in.cnr.it