Messier Collection

M4 - Globular Cluster in Scorpius

M4 is a globular cluster - a dense, gravitationally-bound collection of stars. Globular clusters orbit the galaxy, forming a halo outside of the main body of the galaxy. They are found in almost every galaxy. M4 contains tens of thousands of stars in an area about 75 light years across, 7,000 light years from Earth. It is less densely packed than many globulars so many stars are resolved even in relatively small telescopes. At magnitude 5.9, it is difficult to see with the naked eye but is easily visible in binoculars and small telescopes as a fuzzy patch the size of the full Moon. 5 minute exposures: 3 each R, G, B, and 5 luminosity SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Taken June 19, 2017, Santa Cruz Mountains, California

M8 - Lagoon Nebula

The Lagoon Nebula is a cloud of hydrogen gas where new stars are being formed. It glows red because the newly-formed stars ionize the hydrogen gas. These types of nebulae are called emission nebulae or H II regions. The Lagoon Nebula is about 5000 light years from Earth. 4 R, 3 G, 3B x 5min + 11 x 2min luminosity exposures 16 RGB darks + 26 luminosity darks SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Shot June 21, 2017, Santa Cruz Mountains, California

M13 - Great Globular Cluster in Hercules

M13 is a globular cluster - a dense, gravitationally-bound collection of stars. M13 contains several hundred thousand stars in an area about 145 light years across, 22,000 light years from Earth. It is magnitude 5.8, just barely visible to the naked eye on clear, dark nights. It is easily seen in binoculars and small telescopes as a fuzzy patch nearly the size of the full Moon. Progressively larger telescopes resolve more and more of the stars. 1 minute exposures: 8 R, 7 G, 10 B, and 8 luminosity SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Taken June 28, 2017, Santa Cruz Mountains, California

M17 - Omega Nebula

The Omega Nebula is a cloud of hydrogen gas where new stars are being formed. The newly-formed stars emit ultraviolet light that ionizes the hydrogen gas. This nebula 5000-6000 light years from Earth. 12 R, 12 G, 11 B x 1min + 25 x 2min H-alpha + 17 x 1min luminosity frames SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Shot June 29, 2017, Santa Cruz Mountains, California

M20 - Trifid Nebula

The Trifid Nebula is an "H II region" -- a cloud of hydrogen gas where new stars are being formed. The new stars are hot, therefore blue, emitting ultraviolet light that ionizes the hydrogen gas. The red portion of the nebula is glow from this ionized gas. The blue portion is where star light is being reflected by gas and dust. The dark streaks within the red area are dust lanes that block the light. Thus the Trifid Nebula is a combination of emission, reflection, and dark nebulae, plus an open cluster of stars. It is about 5000 light years from Earth. 5min exposures: 2 R, 3 G, 2 B, 2 H-alpha, 3 OIII, 1 S, 3 luminosity SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Shot June 20, 2017, Santa Cruz Mountains, California

M31 - The Great Galaxy in Andromeda

The Andromeda Galaxy is a spiral galaxy similar to, but somewhat larger than, the Milky Way. It is 2.5 million light years from Earth, and is visible to the naked eye as a faint smudge. There are about 1 trillion stars in this galaxy. 8 x 3min exposures with Canon F2.8L 70-200 zoom at F2.8/200mm, modified Canon XSi. Shot July 13, 2018 at the Golden State Star Party.

M51 - Whirlpool Galaxy

The Whirlpool Galaxy is about 25 million light years from Earth. It was the first galaxy to be identified as a spiral, easily seen in photographs and large telescopes since it presents a face-on view to Earth. 8 x 2min luminosity exposures 8 x 2min darks SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian Shot and processed with Nebulosity Shot May 28, 2017, Santa Cruz Mountains, California

M101 - Pinwheel Galaxy

M101 is a face-on spiral galaxy about 21 million light years from Earth. It is rather larger than our Milky Way, being 170,000 light years across as opposed to the Milky Way's 100,000 light year diameter. The many bright knots are H II regions -- emission nebulae -- where new stars are being formed. M101 contains an estimated 1 trillion stars. 2 min exposures: 3 R, 3 G, 3 B, and 7 luminosity SBIG ST-8300M cooled CCD camera Orion 8" F/3.9 Newtonian with Baader coma corrector Shot and processed with Nebulosity Taken June 15-16, 2017, Santa Cruz Mountains, California

M42

This "RGB" image approximates the true color of the nebula, which is primarily red because it's composed of glowing hydrogen gas.