The Leo Treo
The Leo Trio
M65, M66 and NGC3628
Galaxy Group in Leo

Click here for higher-resolution versions: 1568x1052  2090x1403


The Leo Trio:There are three large galaxies plainly visible in this image, called M65, M66 and NGC3628 (as shown on the picture to the right). All three are spiral galaxies; NGC3628 presents to us edge-on, so we cannot see the spiral structure in this picture. Being within the part of the sky covered by the constellation Leo, they are known by the euphonious name "Leo Trio." They are thought to be about 30-35 million light years away from us, and are physically part of the same galaxy group (not merely in the same line of sight). At that distance, M65 and M66 are about 60,000 light years in diameter, while NGC3628 is about 100,000 light years in diameter (by comparison, our Milky Way galaxy is about 100,000 light years in diameter). Because they are relatively close together, they each show some signs of the gravitational forces they subject on one another. I particularly enjoy picking out the many small, background galaxies in this picture.


Technical Information:

LRGB: 300:90:90:90; L consisted of twenty 15-minute unbinned images; R, G and B consisted of six 15-minute unbinned images each.

Equipment: AP130, SBIG ST-10XME with CFW8 (Astrodon filter set), on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: CCDSoft v5, controlled with CCDAutoPilot3, working in concert with TheSky v6.

Processing: All color images calibrated (darks and dawn flats), debloomed (Ron Wodaski's debloomer), and aligned in CCDSoft v5. Sigma reject performed in Ray Gralak's Sigma pre-beta 11. Luminance layer calibrated and debloomed in CCDSoft; aligned, combined and deconvolved in CCDStack. Color combine in Photoshop. Finish work (curves and levels, increasing saturation, smart sharpen luminance layer) was done in Photoshop CS2.

Location: Data acquired remotely from the Tejas Observatory, located on the grounds of New Mexico Skies, near Mayhill, NM (elevation 7300 feet).

Date: Luminance images taken on the night February 12, 2007. Color images taken during the night of February 15, 2007.

Pixel scale: 1.67 arcseconds per pixel.

CCD Chip temperature: -25C

Seeing: Generally good, but variable.

Transparency: Good.

Moon Phase: Minimal or no moon throughout.

Copyright 2007 Mark de Regt

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