Getting plate-solving status, please wait...

M65, M66, NGC 3628: The "Leo Trio", LRGB, 14 Apr 2017

Technical card

Resolution: 4494x3295

Dates: April 14, 2017

ZWO Blue 31 mm: 17x180" -20C bin 1x1
ZWO Green 31 mm: 17x180" -20C bin 1x1
ZWO Luminance 31 mm: 52x180" -20C bin 1x1
ZWO Red 31 mm: 8x180" -20C bin 1x1

Integration: 4.7 hours

Avg. Moon age: 17.28 days

Avg. Moon phase: 93.00% job: 1539805

RA center: 169.981 degrees

DEC center: 13.322 degrees

Pixel scale: 0.858 arcsec/pixel

Orientation: -89.634 degrees

Field radius: 0.664 degrees

Locations: Mapleton Lateral Observatory, Mapleton, Utah, United States


Still a little more Moon than is good for this kind of image, but this was my last chance to image for a while and the weather was cooperating. Had some trouble finding good guide stars, and my guiding is the next area that needs a lot of work. I kept trying to set things up to get the maximum number of subs before this target set, but apparently I guessed wrong and I only got half as many R subs as I was shooting for before Leo disappeared behind the neighbor's trees. So I had to make do with what I've got. Perhaps as a result, it turned out to be difficult to bring out much color in this image. Still, it's a lot better than my last previous look at the Leo Trio.

Date: 14 Apr 2017
Subject: M65, M66, NGC 3628, The Leo Trio
Scope: AT8IN + High Point Scientific coma corrector
Filters: ZWO 31 mm diameter unmounted L, R, G, B
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + DSI +PHD (Win 10 ASCOM) using predictive PEC algorithm
Camera: ASI1600MM-Cool, -20 °C, Gain 0 Offset 10
Acquisition: Sequence Generator Pro
Exposure: 52x180 L, 8x180 R, 17x180 G, 17x180 B
Stacking: Neb 4.1.5, flats & darks, trans+rot align, Nebulosity 1.5σ stack and align.
Processing: StarTools 1.4.327. Aggressively stretched and deconvoluted the luminance. Combined RGB in Neb 4 and stretched, color balanced, and sharpened in StarTools. Used StarTools' "Repair" module to "repair" some stars that were out of round due to optical problems, but some of the "repaired" stars were probably really faint fuzzies that should not have been messed with. Layered luminance over RGB in Photoshop CC 2014, used Carboni’s Astronomy Tools deep space noise reduction several times, boosted the vibrance a lot and saturation almost as much (masking out some in the core of M66), topped off with AstroFrame.



David Dearden

Sky plot

Sky plot


M65, M66, NGC 3628: The "Leo Trio", LRGB, 14 Apr 2017, David Dearden

In these public groups