The Horsehead Nebula…from L.A.

The Horsehead Nebula

The Horsehead Nebula and Flame Nebula shot with a DSLR from L.A. in H-alpha light

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  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 0.72x field flattener & reducer (f/5)
  • Filter: 12-nm narrowband H-alpha
  • Camera: Canon 60Da
  • Light Frames: 12, 4-min. exposures
  • Calibration: 13 darks, 100 biases, 30 flats
  • Exposure Time: 48 min. (12 x 4 min.)
  • ISO: 1600
  • Pre-Processing: PixInsight
  • Processing: Photoshop CC (processed in a single red channel and flattened)
  • Imaging Location: Los Angeles, Calif.

Photographing wispy deep-sky objects (DSOs) in the light-polluted skies of Los Angeles is not for the faint of heart. L.A. was an early adopter of LED streetlights; so night has now become day, ablaze with broadband sky glow. But those gossamer DSOs can be photographed under such conditions, as the image above of the Horsehead Nebula and Flame Nebula proves. The trick is to use a narrowband filter in front of the camera sensor, which blocks all wavelengths of light except the ones of interest. In this case, the wavelength of interest is the red emission line of hydrogen-alpha at 656 nm…aka, H-alpha. The Horsehead and Flame nebulae both emit at the H-alpha wavelength, so the filter allows their “voices” to be “heard” above the raucous roar of urban light pollution.

This image makes use of a narrowband H-alpha filter with a full-width half-max transmission window of 12 nm. It is a proof-of-concept shot intended to flush out the process and nail down some of the parameters (see bulleted details above). Wind and the meridian precluded taking more light frames, which would have further enhanced the quality and detail of the image. During the imaging session, a very bright LED streetlight gleamed at full intensity about 50 yards away, and the full moon (two days past full) was rising in the east. Yet, the results speak for themselves. It can be done, and done well.

Stay tuned for more narrowband images to come on this website.

Nighttime Lights of L.A.

The city lights of L.A. transform night into day.

2017 Solar Eclipse, Take Two

Eclipse 2017 Corona, HDR Print, Brighter, Reduced

This high-dynamic-range image showcases the solar corona and the Moon during The Great American Eclipse of 2017.

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  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: No
  • Optical Configuration: 0.72x field flattener & reducer (f/5); no solar filter during totality
  • Camera: Canon 60Da
  • Light Frame(s): 6 frames from 1/500 sec to 1 sec
  • Calibration: None (no darks, no flats, no biases)
  • Exposure Time(s): 1/500, 1/250, 1/125, 1/60, 1/30 sec, and 1 sec
  • ISO: 100
  • Processing: Photoshop CC using HDR Pro
  • Imaging Location: Prairie City, Ore.
  • Click for high-quality prints

This high-dynamic-range image of the 2017 solar eclipse, originally posted August 25, 2017, has been reprocessed to reveal more detail of the solar corona and the Moon.

Super-heated plasma escaping from the sun creates the solar corona and becomes the solar wind that blows through our solar system at a million miles per hour. The charged particles that make up the coronal plasma follow the magnetic field lines of the sun and form streamers in the corona, like iron filings around a magnet.

Sunlight reflecting from Earth during the eclipse illuminates the Moon and bounces back to Earth as “earthshine.” Because of this earthshine, lunar features such as the “seas” and several large craters (Tycho, Copernicus, etc.) can be imaged during totality. The blue color of the Moon comes from our blue sky.

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Waxing Crescent

Waxing Crescent

Two-day-old waxing crescent

  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: No
  • Optical Configuration: 2x Barlow (f/14)
  • Camera: Canon 60Da
  • Light Frames: Single frame, 1/125-sec. exposure
  • Calibration: None (no darks, no flats, no biases)
  • Exposure Time: 1/125 sec.
  • ISO: 1250
  • Processing: Photoshop CC
  • Imaging Location: Sierra Nevada Mountains (Altitude: 8,600 ft)

This two-day-old waxing crescent of the Moon was shot while waiting for darkness to fall in the High Sierra.

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The Heart Nebula (IC 1805)

The Heart Nebula (IC 1805)

This H-II emission nebula traces a red heart in the constellation Cassiopeia.

  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 0.72x field flattener & reducer (f/5)
  • Camera: Canon 60Da
  • Light Frames: 25, 6-min. exposures
  • Calibration: None (no darks, no flats, no biases)
  • Exposure Time: 150 min. (25 x 6 min.)
  • ISO: 800
  • Processing: Photoshop CC
  • Imaging Location: Sierra Nevada Mountains (Altitude: 8,600 ft)

About 7,500 light-years away in the constellation Cassiopeia, the feeble red light from a very dim emission nebula traces the shape of a heart in the sky. With an apparent magnitude of only 18.3, the aptly named Heart Nebula requires long exposures to tease out the details of its shape.

Ultraviolet light from the open cluster of stars (Melotte 15) near the nebula’s center stimulates the  re-emission of red light from ionized hydrogen gas (H II) in the interstellar medium. Hints of blue light from doubly ionized interstellar oxygen gas (O III) also can be seen throughout the nebula.

Because the nebula’s size exceeds the widest field of view of the telescope-sensor configuration (1.95° x 1.30°), some parts of the object extend off frame in the image above.

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The Triangulum Galaxy (M33)

Triangulum Galaxy (M33)

The Triangulum Galaxy (M33) is the third largest member of our Local Group.

  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 0.72x field flattener & reducer (f/5)
  • Camera: Canon 60Da
  • Light Frames: 24, 5-min. exposures
  • Calibration: None (no darks, no flats, no biases)
  • Exposure Time: 120 min. (24 x 5 min.)
  • ISO: 800
  • Processing: Photoshop CC
  • Imaging Location: Sierra Nevada Mountains (Altitude: 8,600 ft)

On a very dark and clear autumn night, a sharp eye can spot the Triangulum Galaxy (M33) high in the sky in the constellation Triangulum. At a distance of 3 million light-years, it is one of the farthest objects that can be seen with the naked eye.

The Triangulum Galaxy lives right next door to the Andromeda Galaxy (M31) in the constellation Andromeda, which is the largest member of our Local Group of galaxies that includes Andromeda (#1), our galaxy the Milky Way (#2), and Triangulum (#3). Altogether, our Local Group contains more than 54 galaxies.

The Triangulum Galaxy spans about 60,000 light-years and may contain 40 billion stars, which is about one tenth the number of stars in our galaxy.

[For Tom, whose artful words live on.]

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